Point cloud encoding method, point cloud decoding method, bitstream, encoder, decoder, and storage medium

Abstract

Disclosed in embodiments of the present application are a point cloud encoding method and a point cloud decoding method. The method comprises: when a current RAHT layer uses a hybrid prediction mode, determining an inter-frame reference block corresponding to a current block; on the basis of occupancy information of the current block and occupancy information of the inter-frame reference block, determining an occupancy information difference parameter between the current block and the inter-frame reference block; and on the basis of the occupancy information difference parameter, determining an attribute transform-domain prediction value corresponding to the current block.

Description

Point cloud coding method, code stream, encoder, decoder and storage medium TECHNICAL FIELD

[0001] Embodiments of the present application relate to the technical field of point cloud coding, and particularly relate to a point cloud coding method, a code stream, an encoder, a decoder and a storage medium. BACKGROUND

[0002] In a point cloud compression (PCC) framework, for a geometry-based point cloud compression (G-PCC) coding framework, geometry information of a point cloud and attribute information corresponding to each point are encoded separately. The current G-PCC coding framework contains three attribute encoding methods: predicting transform (PT), lifting transform (LT) and region adaptive hierarchical transform (RAHT). Among them, the first two are point cloud prediction encoding based on the generation order of LOD, and RAHT is adaptive transform of attribute information from bottom to top according to the construction level of octree.

[0003] In related technologies, when performing region adaptive hierarchical prediction transform encoding, if a mixed prediction mode is used, a weighted average calculation based on an inter-frame prediction value and an intra-frame prediction value can be selected to finally obtain an attribute prediction value. However, a simple weighted average cannot obtain the best prediction effect, which limits the performance of point cloud coding to some extent. SUMMARY

[0004] Embodiments of the present application provide a point cloud coding method, a code stream, an encoder, a decoder and a storage medium, which can effectively improve the performance of point cloud coding.

[0005] The technical solutions of the embodiments of the present application can be implemented as follows:

[0006] In a first aspect, the embodiments of the present application provide a decoding method applied to a decoder, and the method comprises:

[0007] In the case that the current RAHT layer uses a mixed prediction mode, determining an inter-frame reference block corresponding to the current block;

[0008] Based on the occupancy information of the current block and the occupancy information of the inter-frame reference block, determining an occupancy information difference parameter between the current block and the inter-frame reference block;

[0009] The attribute transform domain prediction value corresponding to the current block is determined based on the occupancy information difference parameter.

[0010] In a second aspect, an encoding method is provided, which is applied to an encoder, and the method comprises the following steps:

[0011] In the case that the hybrid prediction mode is used in the current RAHT layer, determining an inter-frame reference block corresponding to the current block;

[0012] Based on the occupancy information of the current block and the occupancy information of the inter-frame reference block, determining an occupancy information difference parameter between the current block and the inter-frame reference block;

[0013] The attribute transform domain prediction value corresponding to the current block is determined based on the occupancy information difference parameter.

[0014] In a third aspect, a code stream is provided, which is generated by bit encoding of to-be-encoded information; wherein the to-be-encoded information comprises at least one of the following:

[0015] The attribute transform domain residual value, the prediction mode identification information.

[0016] In a fourth aspect, an encoder is provided, which comprises:

[0017] The first determining unit is configured to, in the case that the hybrid prediction mode is used in the current RAHT layer, determine an inter-frame reference block corresponding to the current block; based on the occupancy information of the current block and the occupancy information of the inter-frame reference block, determine an occupancy information difference parameter between the current block and the inter-frame reference block; and determine the attribute transform domain prediction value corresponding to the current block based on the occupancy information difference parameter.

[0018] In a fifth aspect, an encoder is provided, which comprises a first memory and a first processor; wherein,

[0019] The first memory is configured to store a computer program capable of running on the first processor;

[0020] The first processor is configured to, when the computer program is running, execute the method according to the second aspect.

[0021] In a sixth aspect, a decoder is provided, which comprises:

[0022] The second determining unit is configured to, in the case that the hybrid prediction mode is used in the current RAHT layer, determine an inter-frame reference block corresponding to the current block; based on the occupancy information of the current block and the occupancy information of the inter-frame reference block, determine an occupancy information difference parameter between the current block and the inter-frame reference block; and determine the attribute transform domain prediction value corresponding to the current block based on the occupancy information difference parameter.

[0023] In a seventh aspect, an embodiment of the present application provides a decoder, the decoder comprising a second memory and a second processor; wherein

[0024] The second memory is configured to store a computer program capable of running on the second processor.

[0025] The second processor is configured to execute the method according to the first aspect when running the computer program.

[0026] In an eighth aspect, an embodiment of the present application provides a computer readable storage medium, the computer readable storage medium being configured to store a bitstream generated by the encoding method according to the second aspect.

[0027] The embodiments of the present application provide a point cloud coding method, a bitstream, an encoder, a decoder and a storage medium. In the case that a hybrid prediction mode is used at a current RAHT layer of a coding terminal, an inter-frame reference block corresponding to the current block is determined. Based on occupancy information of the current block and occupancy information of the inter-frame reference block, an occupancy information difference parameter between the current block and the inter-frame reference block is determined. Based on the occupancy information difference parameter, an attribute transform domain prediction value corresponding to the current block is determined. As can be seen, in the embodiments of the present application, the difference between the occupancy information of the current block and the inter-frame reference block is determined, that is, the occupancy information difference parameter between the two is determined. Then, in the subsequent derivation process of the attribute transform domain prediction value, the occupancy information difference parameter is introduced to further determine the attribute transform domain prediction value corresponding to the current block. As can be seen, the attribute transform domain prediction value in the present application is determined based on the difference between the occupancy information of the transform blocks, which can adapt to the real occupancy information of the transform blocks, and thus the performance of point cloud coding can be effectively improved. BRIEF DESCRIPTION OF DRAWINGS

[0028] FIG. 1 is a schematic diagram of a three-dimensional point cloud image;

[0029] FIG. 2 is a partial enlarged view of a three-dimensional point cloud image;

[0030] FIG. 3 is a schematic diagram of six viewing angles of a point cloud image;

[0031] FIG. 4 is a schematic diagram of a data storage format corresponding to a point cloud image;

[0032] FIG. 5 is a schematic diagram of a composition framework of a G-PCC encoder;

[0033] FIG. 6 is a schematic diagram of a composition framework of a G-PCC decoder;

[0034] FIG. 7 is a schematic diagram of a RAHT transformation process along x, y and z directions;

[0035] FIG. 8 is a schematic diagram of a RAHT transformation structure;

[0036] FIG. 9 is a process diagram of a RAHT forward transform;

[0037] FIG. 10 is a process diagram of a RAHT inverse transform;

[0038] FIG. 11 is a structure diagram of an attribute coding block;

[0039] FIG. 12 is a structure diagram of a RAHT attribute inter prediction coding;

[0040] FIG. 13 is a network architecture diagram of a point cloud coding;

[0041] FIG. 14 is a flow diagram of a point cloud decoding method according to an embodiment of the present application;

[0042] FIG. 15 is a diagram of an occupancy situation of a transform block according to an embodiment of the present application;

[0043] FIG. 16 is a diagram of occupancy information according to an embodiment of the present application;

[0044] FIG. 17 is a diagram of occupancy information according to an embodiment of the present application;

[0045] FIG. 18 is a flow diagram of a point cloud encoding method according to an embodiment of the present application;

[0046] FIG. 19 is a diagram of occupancy information difference according to an embodiment of the present application;

[0047] FIG. 20 is a structure diagram of an encoder according to an embodiment of the present application;

[0048] FIG. 21 is a structure diagram of an encoder according to an embodiment of the present application;

[0049] FIG. 22 is a structure diagram of a decoder according to an embodiment of the present application;

[0050] FIG. 23 is a structure diagram of a decoder according to an embodiment of the present application. DETAILED DESCRIPTION

[0051] In order to enable a person skilled in the art to more fully understand the features and technical content of the embodiments of the present application, the implementation of the embodiments of the present application will be described in detail below with reference to the accompanying drawings, which are only used for reference and are not intended to limit the embodiments of the present application.

[0052] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs. The terms used herein are only for the purpose of describing the embodiments of the present application and are not intended to limit the present application.

[0053] In the following description, reference is made to "some embodiments", which describe a subset of all possible embodiments, but it is to be understood that "some embodiments" can be the same subset or different subsets as each other and as other subsets of all possible embodiments, and can be combined with each other and with other subsets of all possible embodiments without conflict.

[0054] It should also be noted that the terms "first", "second", "third" etc. used in the embodiments of the present application are only used to distinguish similar objects, and do not represent a specific order of the objects. Understandably, "first", "second", "third" etc. can be interchanged in a specific order or sequence as allowed, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein.

[0055] Point cloud is a three-dimensional representation of the surface of an object. It can be collected by photoelectric radar, laser radar, laser scanner, multi-view camera and other collection devices.

[0056] Point cloud is a set of discrete points that express the spatial structure and surface properties of a three-dimensional object or scene in a random distribution in space. Figure 1 shows a three-dimensional point cloud image and Figure 2 shows a local enlarged view of a three-dimensional point cloud image. It can be seen that the point cloud surface is composed of densely distributed points.

[0057] A two-dimensional image has information expressed at each pixel point, and the distribution is regular, so there is no need to record the position information. However, the distribution of points in a point cloud in three-dimensional space has randomness and irregularity, so the position of each point in space needs to be recorded in order to fully express a point cloud. Similar to a two-dimensional image, each position has corresponding attribute information during the collection process, which is usually an RGB color value, and the color value reflects the color of the object. For a point cloud, the attribute information corresponding to each point, in addition to color information, also includes reflectance value, which reflects the surface material of the object. Therefore, the points in the point cloud can include point geometric information and point attribute information. For example, the point geometric information can be the three-dimensional coordinate information (x, y, z) of the point, so the point geometric information can also be referred to as the position information of the point. For example, the point attribute information can include color information (three-dimensional color information) and / or reflectance (one-dimensional reflectance information r), etc. For example, the color information can be information on any color space. For example, the color information can be RGB information. Wherein, R represents red (Red, R), G represents green (Green, G), and B represents blue (Blue, B). For another example, the color information can be luminance chrominance (YCbCr, YUV) information. Wherein, Y represents brightness (Luma), Cb (U) represents blue color difference, and Cr (V) represents red color difference.

[0058] According to the laser measurement principle, the point cloud obtained can include the three-dimensional coordinate information of the point and the reflectivity value of the point. For example, according to the photogrammetry principle, the point cloud obtained can include the three-dimensional coordinate information of the point and the three-dimensional color information of the point. For example, the point cloud obtained in combination with the laser measurement and the photogrammetry principle can include the three-dimensional coordinate information of the point, the reflectivity value of the point, and the three-dimensional color information of the point.

[0059] As shown in FIG. 3 and FIG. 4, a point cloud image and its corresponding data storage format are provided. FIG. 3 provides six viewing angles of the point cloud image, and FIG. 4 is composed of a file header information part and a data part. The header information includes the data format, the data representation type, the total number of points of the point cloud, and the content represented by the point cloud. For example, the point cloud is in the “.ply” format, represented by ASCII code, and has a total of 207242 points, each point having three-dimensional coordinate information (x, y, z) and three-dimensional color information (r, g, b).

[0060] The point cloud can be classified according to the acquisition method as follows:

[0061] Static point cloud: the object is static, and the device for acquiring the point cloud is also static;

[0062] Dynamic point cloud: the object is moving, but the device for acquiring the point cloud is static;

[0063] Dynamic acquisition of point cloud: the device for acquiring the point cloud is moving.

[0064] For example, the point cloud can be classified into two categories according to the use as follows:

[0065] Category I: machine perception point cloud, which can be used in autonomous navigation system, real-time inspection system, geographic information system, visual sorting robot, rescue robot, etc.

[0066] Category II: human eye perception point cloud, which can be used in digital cultural heritage, free viewpoint broadcast, three-dimensional immersive communication, three-dimensional immersive interaction, etc.

[0067] The point cloud can flexibly and conveniently express the spatial structure and surface properties of a three-dimensional object or scene, and can provide strong reality under the premise of ensuring accuracy because the point cloud is obtained by directly sampling a real object. Therefore, the point cloud is widely used in virtual reality games, computer-aided design, geographic information systems, autonomous navigation systems, digital cultural heritage, free viewpoint broadcast, three-dimensional immersive remote presentation, three-dimensional reconstruction of biological tissues and organs, etc.

[0068] The acquisition of point cloud mainly has the following ways: computer generation, 3D laser scanning, 3D photogrammetry, etc. The computer can generate the point cloud of virtual three-dimensional objects and scenes; 3D laser scanning can obtain the point cloud of static real-world three-dimensional objects or scenes, and can obtain million-level point cloud per second; 3D photogrammetry can obtain the point cloud of dynamic real-world three-dimensional objects or scenes, and can obtain ten million-level point cloud per second. These technologies reduce the cost and time period of point cloud data acquisition, and improve the accuracy of data. The change of point cloud data acquisition method makes it possible to obtain a large amount of point cloud data, and with the increase of application demand, the processing of massive 3D point cloud data encounters the bottleneck of storage space and transmission bandwidth limitation.

[0069] Exemplarily, taking a point cloud video with a frame rate of 30 frames per second (fps) as an example, the number of points of each frame of point cloud is 700,000, each point has coordinate information xyz (float) and color information RGB (uchar), and the data amount of 10s point cloud video is about 0.7million×(4Byte×3+1Byte×3)×30fps×10s=3.15GB, wherein 1Byte is 10bit, and the YUV sampling format is 4:2:0, the frame rate of 1280×720 two-dimensional video is 24fps, the data amount of 10s is about 1280×720×12bit×24fps×10s≈0.33GB, and the data amount of 10s two-view three-dimensional video is about 0.33×2=0.66GB. As can be seen, the data amount of point cloud video far exceeds that of two-dimensional video and three-dimensional video of the same length. Therefore, in order to better realize data management, save server storage space, and reduce transmission flow and transmission time between server and client, point cloud compression has become a key problem to promote the development of point cloud industry.

[0070] That is, since the point cloud is a collection of massive points, storing the point cloud will not only consume a large amount of memory, but also be not conducive to transmission, and there is no such large bandwidth to support the transmission of the point cloud directly on the network layer without compression, therefore, the point cloud needs to be compressed.

[0071] At present, the point cloud encoding framework that can compress the point cloud can be a Geometry-based Point Cloud Compression (G-PCC) encoding and decoding framework provided by Moving Picture Experts Group (MPEG) or a Video-based Point Cloud Compression (V-PCC) encoding and decoding framework, or an AVS-PCC encoding and decoding framework provided by Audio Video Standard (AVS).

[0072] The following describes the related technology taking the G-PCC coding framework as an example.

[0073] It can be understood that in the point cloud G-PCC coding framework, for the point cloud data to be encoded, the point cloud data is first divided into multiple slices through slice division. In each slice, the geometry information of the point cloud and the attribute information corresponding to each point are encoded separately.

[0074] FIG. 5 shows a schematic diagram of the composition framework of a G-PCC encoder. As shown in FIG. 5, in the geometry coding process, coordinate conversion is performed on the geometry information, so that all the point clouds are contained in a bounding box, and then quantization is performed, which mainly plays a scaling role. Due to the rounding of quantization, the geometry information of a part of the point clouds is the same, and then it is decided based on parameters whether to remove the duplicate points. This process of quantization and removal of duplicate points is also called voxelization process. Then, octree division or prediction tree construction is performed on the bounding box. In this process, the points in the divided leaf nodes are arithmetically encoded to generate a binary geometry bitstream; or the vertices generated by the division are arithmetically encoded (surface fitting based on the vertices) to generate a binary geometry bitstream. In the attribute coding process, after the geometry coding is completed and the geometry information is reconstructed, color conversion is first performed to convert the color information (i.e., attribute information) from the RGB color space to the YUV color space. Then, the reconstructed geometry information is used to recolor the point cloud, so that the unencoded attribute information corresponds to the reconstructed geometry information. Attribute coding is mainly performed on color information. In the color information coding process, there are mainly two transformation methods, one is distance-based lifting transformation depending on level of detail (LOD) division, and the other is direct region adaptive hierarchal transform (RAHT). Both of these two methods convert the color information from the spatial domain to the frequency domain, obtain high-frequency coefficients and low-frequency coefficients through transformation, and finally quantize the coefficients, and then arithmetically encode the quantized coefficients to generate a binary attribute bitstream.

[0075] FIG. 6 shows a schematic diagram of a G-PCC decoder. As shown in FIG. 6, for the obtained binary bitstream, firstly, the geometry bitstream and the attribute bitstream in the binary bitstream are respectively decoded independently. In the decoding of the geometry bitstream, the geometry information of the point cloud is obtained through arithmetic decoding-reconstructing an octree / reconstructing a prediction tree-reconstructing geometry-coordinate inversion. In the decoding of the attribute bitstream, the attribute information of the point cloud is obtained through arithmetic decoding-dequantization-LOD partitioning / RAHT-color inversion, and the point cloud data to be encoded (i.e., the output point cloud) is restored based on the geometry information and the attribute information.

[0076] It should be noted that, as shown in FIG. 5 or FIG. 6, the current geometry coding of G-PCC can be divided into octree-based geometry coding (indicated by a dashed box) and prediction tree-based geometry coding (indicated by a dotted box).

[0077] It should be further noted that the current G-PCC coding framework contains three attribute coding methods: predicting transform (PT), lifting transform (LT), and region adaptive hierarchical transform (RAHT). Among them, the first two are point cloud prediction coding based on the generation order of LOD, and RAHT is adaptive transform of attribute information from bottom to top according to the construction level of the octree.

[0078] Region adaptive hierarchical transform (RAHT) is a Haar wavelet transform, which can transform the attribute information of the point cloud from the spatial domain to the frequency domain, further reducing the correlation between the attributes of the point cloud. The main idea is to transform the nodes in each layer from the X, Y, and Z dimensions in a bottom-up manner according to the octree structure (as shown in FIG. 7), and iterate until the root node of the octree. As shown in FIG. 8, the basic idea is to perform wavelet transform based on the hierarchical structure of the octree, associate the attribute information with the octree nodes, recursively transform the attributes of the occupied nodes in the same parent node in a bottom-up manner, transform the nodes in each layer from the X, Y, and Z dimensions, and continue to transform until the root node of the octree. In the hierarchical transform process, the low-pass / low-frequency (DC) coefficients obtained after the transform of the nodes in the same layer are passed to the nodes in the next layer for further transform, and all high-pass / high-frequency (AC) coefficients can be encoded by an arithmetic encoder.

[0079] In the transform process, the DC coefficients (direct current component) after the transform of the nodes in the same layer are passed to the previous layer for further transform, and the AC coefficients (alternating current component) after the transform of each layer are quantized and encoded. The main transform process will be introduced below.

[0080] Fig. 9 is a schematic diagram of a process of RAHT forward transform, and Fig. 10 is a schematic diagram of a process of RAHT inverse transform. For the RAHT corresponding transform and inverse transform process, it is assumed that g' L,2x+1,y,z are two attribute DC coefficients of mutually adjacent points in the L layer. After linear transform, the information of the L-1 layer is the AC coefficient f' L,2x+1,y,z L，2x，y，z L-1，x，y，z L-1，x，y，z L-1，x，y，z L-1，x，y，z will no longer be transformed, and will be directly quantized and encoded, and g' L,2x+1,y,z will continue to search for neighbors for transform, and if no neighbors are found, it will be directly passed to the L-2 layer, i.e., the RAHT transform is only valid for nodes with neighbors, and nodes without neighbors will be directly passed to the previous layer. In the above transform process, the weights (the number of non-empty child nodes in the node) corresponding to g' L,2x+1,y,z and g' L,2x+2,y,z are w' L,2x+1,y,z and w' L,2x+2,y,z (abbreviated as w' 0 and w' 1), and the weight of g' L,2x+1,y,z is w' L,2x+1,y,z L，2x，y，z L，2x，y，z L-1，x，y，z L-1，x，y，z , and the general transform formula is:

[0081] where T w0，w1 is the transform matrix:

[0082] The transform matrix will be updated adaptively according to the weights corresponding to each point. The above process will be iteratively updated according to the octree partition structure until the root node of the octree.

[0083] In a specific implementation, for the region adaptive hierarchical intra prediction transform coding, prediction can be performed based on the RAHT transform coding. As shown in Fig. 8, the RAHT attribute transform is based on the order of the octree hierarchy, and the attribute transform is continuously performed from the voxel level until the root node is obtained, so as to complete the entire attribute hierarchical transform coding. In the prediction transform coding, the attribute prediction transform coding is also performed based on the order of the octree hierarchy, but is continuously performed from the root node until the voxel level. In each RAHT attribute transform process, the attribute prediction transform coding is performed based on a 2x2x2 block. As shown in Fig. 11, it can be seen that the grid filled block is the current block to be encoded, and the diagonal line filled block is some neighbor block coplanar and collinear with the current block to be encoded. The attribute of the current block is normalized by the following method: node p∈node attribute(p) (3) w node p∈node ​​​​​​​​​1 = {p∈node} (4) a node = A node / w node (5)

[0084] Firstly, the attribute of the current block can be obtained by the attribute of the point contained in the current block, that is, A node Secondly, the mean value a node of the attribute of the current block is obtained by normalizing the attribute of the current block with the number of points in the current block.

[0085] In another specific implementation, for the adaptive region adaptive hierarchical inter prediction transform coding, in the G-PCC attribute inter prediction coding scheme, the process is similar to the intra prediction coding. Firstly, the RAHT attribute transform coding structure is constructed based on the geometric information, that is, the transform is continuously performed at the voxel level until the root node is obtained, so as to complete the hierarchical transform coding of the entire attribute. In this way, the intra coding structure and the inter coding structure are constructed. The inter coding structure of the RAHT attribute can be seen from FIG. 12.

[0086] As shown in FIG. 12, firstly, the geometric information of the current to-be-coded node is used to obtain the homologous prediction node of the to-be-coded node in the reference frame, and secondly, the geometric information and the attribute information of the reference node are used to obtain the predicted attribute of the current to-be-coded node.

[0087] Among them, the attribute prediction value of the current to-be-coded node is obtained according to the following two different ways:

[0088] ① The inter prediction node of the current node is valid: that is, the homologous node exists, and the attribute of the prediction node is directly taken as the attribute prediction value of the current to-be-coded node;

[0089] ② The inter prediction node of the current node is invalid: that is, the homologous node does not exist, and the attribute prediction value of the intra adjacent node is used as the attribute prediction value of the to-be-coded node.

[0090] Finally, the attribute of the current to-be-coded node is predicted by using the obtained attribute prediction value, so as to complete the prediction coding of the entire attribute.

[0091] In another specific implementation, for the adaptive region adaptive hierarchical prediction transform coding, for each layer of the RAHT transform, firstly, a flag representing the prediction mode of the layer is decoded, the flag is equal to 0 for the intra prediction mode or the hybrid prediction mode (Hybrid prediction), the flag is equal to 1 for the inter prediction mode, and the flag is equal to 2 for the non-prediction mode.

[0092] When flag = 0, at the decoding end, when K <= current layer <= M, the mixed prediction mode is used, otherwise, the intra prediction mode is used, K and M are known at the decoding end.

[0093] In the related art, when performing the region adaptive hierarchical prediction transform coding, if the mixed prediction mode is used, the inter prediction value and the intra prediction value can be selected to perform the weighted average calculation, and finally the attribute prediction value is obtained. However, the simple weighted average cannot obtain the best prediction effect, which limits the performance of the point cloud coding to a certain extent.

[0094] To solve the above problems, the embodiment of the present application provides a point cloud coding method, in the case that the current RAHT layer uses the mixed prediction mode, the decoder determines the inter reference block corresponding to the current block; determines the occupancy information difference parameter between the current block and the inter reference block based on the occupancy information of the current block and the occupancy information of the inter reference block; and determines the attribute transform domain prediction value corresponding to the current block based on the occupancy information difference parameter. As can be seen, in the embodiment of the present application, the difference between the occupancy information of the current block and the inter reference block can be determined, that is, the occupancy information difference parameter between the two is determined, and then the occupancy information difference parameter is introduced in the subsequent derivation process of the attribute transform domain prediction value to further determine the attribute transform domain prediction value corresponding to the current block. As can be seen, the attribute transform domain prediction value in the present application is determined based on the difference between the occupancy information of the transform blocks, which can adapt to the real occupancy information of the transform blocks, and thus the performance of the point cloud coding can be effectively improved.

[0095] It can be understood that the embodiment of the present application provides a network architecture of a point cloud coding system including a decoding method and an encoding method, and FIG. 13 is a schematic diagram of a network architecture of a point cloud coding. As shown in FIG. 13, the network architecture includes one or more electronic devices 13 to 1N and a communication network 01, wherein the electronic devices 13 to 1N can perform video interaction through the communication network 01. The electronic devices in the implementation process can be various types of devices with point cloud coding function, for example, the electronic devices can include mobile phones, tablet computers, personal computers, personal digital assistants, navigation instruments, digital phones, video phones, televisions, sensing devices, servers, etc., and the embodiment of the present application is not limited.

[0096] Among them, the decoder or the encoder in the embodiment of the present application can be the above-mentioned electronic device. That is, the electronic device in the embodiment of the present application has the point cloud coding function, and generally includes a point cloud encoder (i.e. an encoder) and a point cloud decoder (i.e. a decoder).

[0097] The embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0098] In an embodiment of the present application, FIG. 14 is a schematic diagram of an implementation flow of a point cloud decoding method according to an embodiment of the present application. As shown in FIG. 14, the method of the decoder for decoding the point cloud can include the following steps:

[0099] In step 101, in the case that the current RAHT layer uses the hybrid prediction mode, the inter-frame reference block corresponding to the current block is determined.

[0100] In an embodiment of the present application, if the current RAHT layer uses the hybrid prediction mode, the inter-frame reference block corresponding to the current block can be determined first.

[0101] It should be noted that the decoding method according to the embodiments of the present application is applied to a point cloud decoder (which can be referred to as a "decoder" for short). The method can refer to a point cloud decoding method, and specifically refers to a point cloud attribute decoding method.

[0102] It should be noted that in the embodiments of the present application, in the RAHT attribute transformation, the order of the RAHT attribute transformation is to perform division from the root node until the voxel level is reached, and specifically, the division is stopped when the unit cube of 1x1x1 size is reached, thereby completing the encoding and reconstruction of the entire point cloud attribute. Here, the layer obtained by performing downsampling along the Z direction, the Y direction and the X direction each time is a RAHT transformation layer, that is, layer. Then, until the unit cube of 1x1x1 size is reached, it indicates that the voxel level has been reached.

[0103] It can be understood that in the embodiments of the present application, the current RAHT layer can be a RAHT transformation layer corresponding to the current point cloud.

[0104] In an embodiment of the present application, the code stream can be decoded first to determine the prediction mode identification information corresponding to the current RAHT layer, and then the prediction mode corresponding to the current RAHT layer can be determined based on the prediction mode identification information.

[0105] Further, in an embodiment of the present application, the prediction mode identification information corresponding to the current RAHT layer can be used to determine the prediction mode used by the current RAHT layer. The prediction mode corresponding to the current RAHT layer can include an inter-frame prediction mode, an intra-frame prediction mode, a hybrid prediction mode (Hybrid prediction), and can also include a skip prediction transformation.

[0106] Further, in an embodiment of the present application, when determining the prediction mode corresponding to the current RAHT layer, the prediction mode identification information corresponding to the current RAHT layer can be determined by decoding the code stream, and then the prediction mode corresponding to the current RAHT layer can be determined according to the prediction mode identification information.

[0107] It should be noted that in the embodiments of the present application, the prediction mode identifier information corresponding to the current RAHT layer can be attribute header corresponding syntax element.

[0108] For example, in some embodiments, the prediction mode identifier information can be placed in a vector form array in the attribute header. Each RAHT layer corresponds to a prediction mode identifier information. For example, if the current point cloud corresponds to 10 RAHT layers, the vector needs to correspond to 10 prediction mode identifier information.

[0109] For example, in some embodiments, the prediction mode identifier information can be determined by the attribute header corresponding to the slice, or by the attribute header corresponding to the frame. The present application does not make specific limitation.

[0110] It can be understood that in the embodiments of the present application, the current RAHT layer can be any RAHT transform layer corresponding to the current point cloud, and accordingly, the prediction mode of the current RAHT layer can be determined by the prediction mode identifier information corresponding to the current RAHT layer.

[0111] In the embodiments of the present application, in the case of determining that the current RAHT layer uses the hybrid prediction mode, the inter-frame reference block corresponding to the current block can be determined first.

[0112] It can be understood that in the embodiments of the present application, the current block can be a to-be-decoded transform block in the current RAHT layer, and the inter-frame reference block corresponding to the current block can be a reconstructed transform block in the reference image corresponding to the current image, which has the same or corresponding geometric information as the current block.

[0113] It should be noted that in the embodiments of the present application, the geometric information at least includes any one of the following information: spatial Morton code information, spatial Hilbert code information, spatial coordinate information, spherical coordinate information, polar coordinate information.

[0114] That is, in the embodiments of the present application, the inter-frame reference block corresponding to the current block can be a reconstructed transform block in the reference image determined based on the geometric information of the current block.

[0115] Step 102, based on the occupancy information of the current block and the occupancy information of the inter-frame reference block, determine the occupancy information difference parameter between the current block and the inter-frame reference block.

[0116] In the embodiments of the present application, if the current RAHT layer uses the hybrid prediction mode, after determining the inter-frame reference block corresponding to the current block, the occupancy information difference parameter between the current block and the inter-frame reference block can be further determined based on the occupancy information of the current block and the occupancy information of the inter-frame reference block.

[0117] In the related art, since the compression of the point cloud is to first decode the geometry and then decode the attribute. Therefore, when performing the RAHT compression (attribute) on each current transform block, the geometry information of the to-be-decoded point cloud slice can be known in advance, and then the occupancy information of the transform block can be determined.

[0118] That is to say, in the embodiments of the present application, the geometry information of the nodes in the current point cloud has been completely decoded before the attribute decoding of the current RAHT layer.

[0119] It can be understood that in the embodiments of the present application, the geometry information of the decoded point cloud can be used to further determine the occupancy information of the current block and the occupancy information of the corresponding inter-frame reference block.

[0120] In the embodiments of the present application, the occupancy information can be used to determine the occupancy situation of the transform block. The occupancy information can be represented in binary, for example, the occupancy information can be used to represent the occupancy situation of the transform block in binary by 0 or 1, 0 represents not occupying, and 1 represents occupying.

[0121] Exemplarily, in some embodiments, FIG. 15 is a schematic diagram of the occupancy situation of the transform block according to the embodiments of the present application, as shown in FIG. 15, when the RAHT transform is from the L-1 layer to the L-2 layer, the occupancy situation of the white block is not occupying, and the occupancy situation of the gray block is occupying.

[0122] Exemplarily, in some embodiments, FIG. 16 is a schematic diagram of the occupancy information according to the embodiments of the present application, as shown in FIG. 16, the occupancy situation of the transform block is represented in binary by 0 or 1. 0 represents not occupying, and 1 represents occupying, the occupancy information of the transform block a is 11111111.

[0123] Exemplarily, in some embodiments, FIG. 17 is a schematic diagram of the occupancy information according to the embodiments of the present application, as shown in FIG. 17, the occupancy situation of the transform block is represented in binary by 0 or 1. 0 represents not occupying, and 1 represents occupying, the occupancy information of the transform block b is 00000000.

[0124] Further, in the embodiments of the present application, according to the determined occupancy information of the current block and the occupancy information of the inter-frame reference block, an occupancy information difference parameter between the current block and the inter-frame reference block can be further determined. Wherein, the occupancy information difference parameter can be the occupancy information difference between the occupancy information of the current block and the occupancy information of the inter-frame reference block.

[0125] It can be understood that, in the embodiments of the present application, the occupancy information difference parameter (i.e. occupancy information difference) is used to determine the number of occupancy information differences, as shown in the figure, the occupancy information difference between the transform block a and the transform block b is 8.

[0126] Exemplarily, in some embodiments, when determining the occupancy information difference parameter between the current block and the inter-frame reference block, assuming that the occupancy information of the current block is A and the occupancy information of the inter-frame reference block is B, A and B are respectively 8-bit binary numbers, the occupancy information difference parameter between the current block and the inter-frame reference block can be obtained by popcent(A∧B). Wherein, A∧B is the bitwise XOR operation of A and B, the same bit is 0, and different bits are 1. popcent() can count the number of 1 in the binary.

[0127] Exemplarily, in some embodiments, assuming that the occupancy information A of the current block is represented as 11111111 and the occupancy information B of the inter-frame reference block is represented as 00000000, then the occupancy information difference parameter between the current block and the inter-frame reference block can be determined by popcent(A∧B) as 8, i.e. 8 bits of the occupancy information between the current block and the inter-frame reference block are different.

[0128] Exemplarily, in some embodiments, assuming that the occupancy information A of the current block is represented as 10001101 and the occupancy information B of the inter-frame reference block is represented as 01110011, then the occupancy information difference parameter between the current block and the inter-frame reference block can be determined by popcent(A∧B) as 7, i.e. there are 7 bits of the occupancy information between the current block and the inter-frame reference block are different.

[0129] It can be understood that, in the embodiments of the present application, since the occupancy information is an 8-bit binary number, therefore, the occupancy information difference parameter determined based on the difference of the occupancy information can be an integer greater than or equal to 0 and less than or equal to 8.

[0130] Step 103, determining the attribute transform domain prediction value corresponding to the current block based on the occupancy information difference parameter.

[0131] In the embodiments of the present application, after determining the occupancy information difference parameter between the current block and the inter-frame reference block based on the occupancy information of the current block and the occupancy information of the inter-frame reference block, the attribute transform domain prediction value corresponding to the current block can be further determined based on the occupancy information difference parameter.

[0132] That is, in the embodiments of the present application, for the hybrid prediction mode, the information of the occupancy information difference parameter between the current block and the corresponding inter-frame reference block can be introduced when determining the attribute transform domain prediction value of the current block. Wherein, for different occupancy information difference parameters, the specific process of determining the attribute transform domain prediction value of the current block through the inter-frame transform domain prediction value and / or the intra-frame transform domain prediction value corresponding to the current block can also be different, that is, according to the difference of the occupancy information between the current block and the intra-frame reference block, the corresponding prediction mode can be adopted to obtain the corresponding prediction result (the attribute transform domain prediction value of the current block), so as to greatly improve the prediction performance.

[0133] It should be noted that in the embodiments of the present application, for the hybrid prediction mode (Hybrid prediction), the attribute transform domain prediction value of the current block can be determined based on the inter-frame transform domain prediction value and / or the intra-frame transform domain prediction value corresponding to the current block.

[0134] Correspondingly, in the embodiments of the present application, the inter-frame transform domain prediction value corresponding to the current block can be determined, and / or the intra-frame transform domain prediction value corresponding to the current block can be determined.

[0135] In the embodiments of the present application, the inter-frame transform domain prediction value is the attribute transform domain value of the inter-frame reference block corresponding to the current block. Wherein, the inter-frame reference block is a reconstructed transform block, so the attribute transform domain value of the obtained inter-frame reference block can be directly determined as the inter-frame transform domain prediction value corresponding to the current block.

[0136] In the embodiments of the present application, the intra-frame transform domain prediction value is the attribute transform domain value of the intra-frame reference block corresponding to the current block. Wherein, the intra-frame reference block is a reconstructed transform block, so the attribute transform domain value of the obtained intra-frame reference block can be directly determined as the intra-frame transform domain prediction value corresponding to the current block.

[0137] Further, in the embodiments of the present application, when determining the attribute transform domain prediction value of the current block based on the occupancy information difference parameter, the attribute transform domain prediction value of the current block can be determined based on the occupancy information difference parameter, and the inter-frame transform domain prediction value and / or the intra-frame transform domain prediction value.

[0138] In the embodiments of the present application, when determining the attribute transform domain prediction value of the current block, based on the occupancy information difference parameter and the inter-frame transform domain prediction value and / or the intra-frame transform domain prediction value, the attribute transform domain prediction value of the current block can be determined based on the comparison result of the occupancy information difference parameter and the preset value, and the inter-frame transform domain prediction value and / or the intra-frame transform domain prediction value. The embodiments of the present application can be applied to the video coding field, and can improve the prediction performance of the video coding.

[0139] That is, in the embodiments of the present application, the placeholder information difference parameter and the preset value can be compared first, and then based on the comparison result of the two, the attribute transform domain prediction value of the current block is determined further in combination with the inter-frame transform domain prediction value and / or the intra-frame transform domain prediction value.

[0140] It can be understood that in the embodiments of the present application, the placeholder information difference parameter can determine the difference between the current block and the corresponding inter-frame reference block, and accordingly, the comparison result of the placeholder information difference parameter and the preset value can determine whether to use the inter-frame transform domain prediction value to determine the attribute transform domain prediction value of the current block, or can determine whether to use only the intra-frame transform domain prediction value to determine the attribute transform domain prediction value of the current block, or can determine how to combine the inter-frame transform domain prediction value and the intra-frame transform domain prediction value to determine the attribute transform domain prediction value of the current block.

[0141] It can be understood that in the embodiments of the present application, the preset value can include one or more numerical values, wherein the preset value can be an integer greater than or equal to 0.

[0142] Exemplarily, in some embodiments, the preset value can include a first value, wherein the first value can be an integer greater than or equal to 0, for example, the first value is 2.

[0143] In the embodiments of the present application, when the attribute transform domain prediction value of the current block is determined based on the comparison result of the placeholder information difference parameter and the preset value, and the inter-frame transform domain prediction value and / or the intra-frame transform domain prediction value, in the case that the comparison result is that the placeholder information difference parameter is greater than the first value, the attribute transform domain prediction value of the current block is determined based on the intra-frame transform domain prediction value.

[0144] Exemplarily, in some embodiments, if the placeholder information difference parameter is greater than 2 (the first value), it can be considered that the difference between the current block and the inter-frame reference block is large, and if the attribute transform domain prediction value of the current block is determined in combination with the inter-frame transform domain prediction value, there can be a problem of low prediction accuracy, therefore, it can be selected to determine the attribute transform domain prediction value of the current block only using the intra-frame transform domain prediction value corresponding to the current block.

[0145] Exemplarily, in some embodiments, in the case that the comparison result is that the placeholder information difference parameter is greater than or equal to the first value, the attribute transform domain prediction value of the current block can also be determined based on the intra-frame transform domain prediction value. For example, if the placeholder information difference parameter is greater than or equal to 2 (the first value), it can be considered that the difference between the current block and the inter-frame reference block is large, therefore, it can be selected to determine the attribute transform domain prediction value of the current block only using the intra-frame transform domain prediction value corresponding to the current block.

[0146] Exemplarily, in some embodiments, the preset values can include a first value and a second value, where the first value and the second value can be integers greater than or equal to 0, for example, the first value is 2 and the second value is 1.

[0147] In the embodiments of the present application, when determining the attribute transform domain prediction value of the current block based on the comparison result of the placeholder information difference parameter and the preset value, and the inter-frame transform domain prediction value and / or the intra-frame transform domain prediction value, in the case that the comparison result is that the placeholder information difference parameter is less than or equal to the first value and greater than or equal to the second value, the attribute transform domain prediction value of the current block is determined based on the inter-frame transform domain prediction value and the intra-frame transform domain prediction value.

[0148] It can be understood that, in the embodiments of the present application, for the case that the placeholder information difference parameter is less than or equal to the first value and greater than or equal to the second value, when determining the attribute transform domain prediction value of the current block based on the inter-frame transform domain prediction value and the intra-frame transform domain prediction value, the average of the inter-frame transform domain prediction value and the intra-frame transform domain prediction value can be directly determined as the attribute transform domain prediction value of the current block.

[0149] Exemplarily, in some embodiments, if the placeholder information difference parameter is greater than or equal to 1 (the second value) and less than or equal to 2 (the first value), it can be considered that there is a certain degree of difference between the current block and the inter-frame reference block, and if only the inter-frame transform domain prediction value is used to determine the attribute transform domain prediction value of the current block, there can be a problem of low prediction accuracy, therefore, it can be selected to determine the attribute transform domain prediction value of the current block by combining the inter-frame transform domain prediction value and the intra-frame transform domain prediction value corresponding to the current block.

[0150] Exemplarily, in some embodiments, in the case that the placeholder information difference parameter is greater than or equal to the second value and less than the first value, it can also be selected to determine the attribute transform domain prediction value of the current block by combining the inter-frame transform domain prediction value and the intra-frame transform domain prediction value corresponding to the current block. For example, if the placeholder information difference parameter is greater than or equal to 1 (the second value), and less than 2 (the first value), it can be considered that there is a certain degree of difference in the current block and the inter-frame reference block, therefore, it can be selected to determine the attribute transform domain prediction value of the current block based on the inter-frame transform domain prediction value corresponding to the current block and the intra-frame transform domain prediction value.

[0151] Exemplarily, in some embodiments, in the case that the placeholder information difference parameter is less than the second value and greater than or equal to the first value, it can also be selected to determine the attribute transform domain prediction value of the present block by combining the inter-frame transform domain prediction value and the intra-frame transform domain prediction value corresponding the current block. For example, if the placeholder information difference parameter is greater than 1 (the second value) and less than or equal to 2 (the first value), it can be considered that there is a certain degree of difference between the current block and the inter- frame reference block, therefore, it can be selected to determine the attribute transform domain prediction value of the present block by combining the inter-frame domain prediction value and the intra-frame transform domain prediction value corresponding to the current block.

[0152] For example, in some embodiments, when the occupancy information difference parameter is greater than the second value and less than the first value, the attribute transform domain prediction value of the current block can also be determined by combining the inter transform domain prediction value and the intra transform domain prediction value corresponding to the current block. For example, if the occupancy information difference parameter is greater than 1 (the second value) and less than 2 (the first value), it can be considered that there is a certain degree of difference between the current block and the inter reference block, and thus the attribute transform domain prediction value of the current block can be determined by combining the inter transform domain prediction value and the intra transform domain prediction value corresponding to the current block.

[0153] For example, in some embodiments, the preset value can include a second value, where the second value can be an integer greater than or equal to 0, for example, the second value is 1.

[0154] In the embodiments of the present application, when the attribute transform domain prediction value of the current block is determined based on the comparison result of the occupancy information difference parameter and the preset value, and the inter transform domain prediction value and / or the intra transform domain prediction value, when the comparison result is that the occupancy information difference parameter is less than the second value, the attribute transform domain prediction value of the current block is determined based on the inter transform domain prediction value.

[0155] For example, in some embodiments, if the occupancy information difference parameter is less than 1 (the second value), it can be considered that the difference between the current block and the inter reference block is small, and thus it can be selected to ignore and only use the inter transform domain prediction value to determine the attribute transform domain prediction value of the current block to obtain a more accurate prediction result, and thus it can be selected to only use the inter transform domain prediction value corresponding to the current block to determine the attribute transform domain prediction value of the current block.

[0156] For example, in some embodiments, when the comparison result is that the occupancy information difference parameter is less than or equal to the second value, the attribute transform domain prediction value of the current block can also be determined based on the inter transform domain prediction value. For example, if the occupancy information difference parameter is greater than or equal to 1 (the second value), it can be considered that the difference between the current block and the inter reference block is small, and thus it can be selected to only use the inter transform domain prediction value corresponding to the current block to determine the attribute transform domain prediction value of the current block.

[0157] For example, in some embodiments, the preset value can include a third value, where the third value can be an integer greater than or equal to 0, for example, the third value is 2.

[0158] In the embodiments of the present application, when determining the attribute transform domain prediction value of the current block based on the comparison result of the placeholder information difference parameter and the preset value, and the inter-frame transform domain prediction value and / or the intra-frame transform domain prediction value, in the case that the comparison result is that the placeholder information difference parameter is greater than the third value, the attribute transform domain prediction value of the current block is determined based on the inter-frame transform domain prediction value and the intra-frame transform domain prediction value; and in the case that the placeholder information difference parameter is less than or equal to the third value, the attribute transform domain prediction value of the current block is determined based on the preset weight parameter, the inter-frame transform domain prediction value and the intra-frame transform domain prediction value.

[0159] For example, in some embodiments, the attribute transform domain prediction value of the current block can be determined by combining the inter-frame transform domain prediction value and the intra-frame transform domain prediction value corresponding to the current block. In this case, how to combine the inter-frame transform domain prediction value and the intra-frame transform domain prediction value to determine the attribute transform domain prediction value of the current block can be further selected according to the comparison result of the placeholder information difference parameter and the third value. For example, if the placeholder information difference parameter is greater than the third value, the attribute transform domain prediction value of the current block can be directly determined based on the inter-frame transform domain prediction value and the intra-frame transform domain prediction value; and if the placeholder information difference parameter is less than or equal to the third value, the proportion of the inter-frame transform domain prediction value and the intra-frame transform domain prediction value can be adjusted according to the preset weight parameter, and then the attribute transform domain prediction value of the current block is determined.

[0160] It can be understood that, in the embodiments of the present application, in the case that the placeholder information difference parameter is greater than the third value, when the attribute transform domain prediction value of the current block is determined based on the inter-frame transform domain prediction value and the intra-frame transform domain prediction value, the average of the inter-frame transform domain prediction value and the intra-frame transform domain prediction value can be directly determined as the attribute transform domain prediction value of the current block.

[0161] In the embodiments of the present application, the preset weight parameter can include a weight corresponding to the inter-frame transform domain prediction value and a weight corresponding to the intra-frame transform domain prediction value. That is, the weight corresponding to the inter-frame transform domain prediction value and the weight corresponding to the intra-frame transform domain prediction value can be preset, and then in the process of combining the inter-frame transform domain prediction value and the intra-frame transform domain prediction value for weighted operation, the preset weight parameter can be used to control the proportion of the inter-frame transform domain prediction value and the intra-frame transform domain prediction value.

[0162] For example, in some embodiments, the preset weight parameter can be any numerical value greater than or equal to 0, for example, the weight corresponding to the inter-frame transform domain prediction value is 1 / 4, the weight corresponding to the intra-frame transform domain prediction value is 3 / 4, or the weight corresponding to the inter-frame transform domain prediction value is 3 / 4, and the weight corresponding to the intra-frame transform domain prediction value is 1 / 4.

[0163] For example, in some embodiments, if the placeholder information difference parameter is greater than 2 (the third value), the average of the inter transform domain prediction value and the intra transform domain prediction value can be selected as the attribute transform domain prediction value of the current block; if the placeholder information difference parameter is less than or equal to 2 (the third value), the inter transform domain prediction value and the intra transform domain prediction value can be weighted and calculated according to the weight of the inter transform domain prediction value being 1 / 4 and the weight of the intra transform domain prediction value being 3 / 4, and finally the attribute transform domain prediction value of the current block is determined.

[0164] For example, in some embodiments, when the comparison result is that the placeholder information difference parameter is greater than or equal to the third value, i.e., the placeholder information difference parameter is greater than or equal to 2 (the third value), the average of the inter transform domain prediction value and the intra transform domain prediction value can also be selected as the attribute transform domain prediction value of the current block; correspondingly, when the comparison result is that the placeholder information difference parameter is less than the third value, i.e., the placeholder information difference parameter is less than 2 (the third value), the inter transform domain prediction value and the intra transform domain prediction value can also be weighted and calculated according to the weight of the inter transform domain prediction value being 1 / 4 and the weight of the intra transform domain prediction value being 3 / 4, and finally the attribute transform domain prediction value of the current block is determined.

[0165] It can be understood that in the embodiments of the present application, the values of the preset values, such as the first value, the second value, and the third value, can all be the same, all be different, or partially the same, which is not specifically limited in the present application. For example, the first value and the third value can be the same, both being 2; the first value and the second value can be different.

[0166] In the embodiments of the present application, when the attribute transform domain prediction value of the current block is determined based on the placeholder information difference parameter and the inter transform domain prediction value and / or the intra transform domain prediction value, the first weight corresponding to the inter transform domain prediction value and the second weight corresponding to the intra transform domain prediction value can be first determined based on the comparison result of the placeholder information difference parameter and the preset value; then the attribute transform domain prediction value of the current block can be further determined based on the first weight, the second weight, the inter transform domain prediction value, and the intra transform domain prediction value.

[0167] That is, in the embodiments of the present application, the placeholder information difference parameter and the preset value can be compared first, and then the first weight corresponding to the inter transform domain prediction value and the second weight corresponding to the intra transform domain prediction value can be determined based on the comparison result, and then the inter transform domain prediction value and the intra transform domain prediction value can be weighted and calculated based on the first weight and the second weight, and finally the attribute transform domain prediction value of the current block is determined.

[0168] It can be understood that in the embodiments of the present application, the first weight and the second weight can be the same or different, and the first weight or the second weight can be 0, which is not specifically limited in the present application.

[0169] It can be understood that in the embodiments of the present application, the preset value can include one or more numerical values, wherein the preset value can be an integer greater than or equal to 0.

[0170] Exemplarily, in some embodiments, the preset value can include a first value, wherein the first value can be an integer greater than or equal to 0, for example, the first value is 2.

[0171] In the embodiments of the present application, when determining the first weight corresponding to the inter-frame transform domain prediction value and the second weight corresponding to the intra-frame transform domain prediction value based on the comparison result of the placeholder information difference parameter and the preset value, in the case that the comparison result is that the placeholder information difference parameter is greater than the first value, it is determined that the first weight is 0.

[0172] Exemplarily, in some embodiments, if the placeholder information difference parameter is greater than 2 (the first value), it can be considered that the difference between the current block and the inter-frame reference block is large, and if the attribute transform domain prediction value of the current block is determined in combination with the inter-frame transform domain prediction value, there can be a problem of low prediction accuracy, therefore, the inter-frame transform domain prediction value can be selected not to be used, and therefore the first weight corresponding to the inter-frame transform domain prediction value can be determined as 0.

[0173] Exemplarily, in some embodiments, in the case that the comparison result is that the placeholder information difference parameter is greater than or equal to the first value, the inter-frame transform domain prediction value can also be selected not to be used to determine the attribute transform domain prediction value of the current block. For example, if the placeholder information difference parameter is greater than or equal to 2 (the first value), it can be considered that the difference between the current block and the inter-frame reference block is large, and therefore the first weight corresponding to the inter-frame transform domain prediction value can be determined as 0.

[0174] Correspondingly, in the embodiments of the present application, for the case that the attribute transform domain prediction value of the current block is not determined using the inter-frame transform domain prediction value, it can be considered that only the intra-frame transform domain prediction value corresponding to the current block is used to determine the attribute transform domain prediction value of the current block, and at this time, the second weight corresponding to the intra-frame transform domain prediction value can be 1.

[0175] Exemplarily, in some embodiments, the preset value can include a first value and a second value, wherein the first value and the second value can be integers greater than or equal to 0, for example, the first value is 2 and the second value is 1.

[0176] In the embodiments of this application, when determining the first weight corresponding to the inter-frame transform domain prediction value and the second weight corresponding to the intra-frame transform domain prediction value based on the comparison result of the placeholder information difference parameter and the preset value, if the comparison result is that the placeholder information difference parameter is less than or equal to the first value and greater than or equal to the second value, the first weight and the second weight are determined to be equal.

[0177] It is understood that, in the embodiments of this application, when the placeholder information difference parameter is less than or equal to the first value and greater than or equal to the second value, the average of the inter-frame transform domain prediction value and the intra-frame transform domain prediction value can be selected as the attribute transform domain prediction value of the current block. Therefore, the first weight and the second weight can be set to be equal.

[0178] For example, in some embodiments, if the placeholder information difference parameter is greater than or equal to 1 (second value) and less than or equal to 2 (first value), then it can be considered that there is a certain degree of difference between the current block and the inter-frame reference block. The attribute transform domain prediction value of the current block can be determined by combining the inter-frame transform domain prediction value and the intra-frame transform domain prediction value corresponding to the current block. For example, the first weight and the second weight can be set to be equal. For example, the first weight and the second weight are both 1 / 2.

[0179] For example, in some embodiments, when the placeholder information difference parameter is greater than or equal to the second value and less than the first value, it is also possible to determine that the first weight and the second weight are equal. For example, if the placeholder information difference parameter is greater than or equal to 1 (the second value) and less than 2 (the first value), then it can be considered that there is a certain degree of difference between the current block and the inter-frame reference block. Therefore, it is possible to combine the inter-frame transform domain prediction value and the intra-frame transform domain prediction value corresponding to the current block to determine the attribute transform domain prediction value of the current block. For example, the first weight and the second weight are both determined to be 1 / 2.

[0180] For example, in some embodiments, when the placeholder information difference parameter is greater than a second value and less than or equal to a first value, it is also possible to determine that the first weight and the second weight are equal. For example, if the placeholder information difference parameter is greater than 1 (the second value) and less than or equal to 2 (the first value), then it can be considered that there is a certain degree of difference between the current block and the inter-frame reference block. Therefore, it is possible to combine the inter-frame transform domain prediction value and the intra-frame transform domain prediction value corresponding to the current block to determine the attribute transform domain prediction value of the current block. For example, the first weight and the second weight are both determined to be 1 / 2.

[0181] For example, in some embodiments, when the placeholder information difference parameter is greater than a second value and less than a first value, it is also possible to determine that the first weight and the second weight are equal. For example, if the placeholder information difference parameter is greater than 1 (the second value) and less than 2 (the first value), then it can be considered that there is a certain degree of difference between the current block and the inter-frame reference block. Therefore, it is possible to combine the inter-frame transform domain prediction value and the intra-frame transform domain prediction value corresponding to the current block to determine the attribute transform domain prediction value of the current block. For example, the first weight and the second weight are both determined to be 1 / 2.

[0182] For example, in some embodiments, the preset value may include a second value, wherein the second value may be an integer greater than or equal to 0, for example, the second value is 1.

[0183] In the embodiments of this application, when determining the first weight corresponding to the inter-frame transform domain prediction value and the second weight corresponding to the intra-frame transform domain prediction value based on the comparison result of the placeholder information difference parameter and the preset value, the second weight is determined to be 0 if the placeholder information difference parameter is less than the second value.

[0184] For example, in some embodiments, if the placeholder information difference parameter is less than 1 (second value), then it can be considered that the difference between the current block and the inter-frame reference block is small and can be ignored. Only the inter-frame transform domain prediction value is used to determine the attribute transform domain prediction value of the current block to obtain a more accurate prediction result. Therefore, it is possible to choose not to use the intra-frame transform domain prediction value corresponding to the current block. Therefore, it is possible to choose to determine the second weight corresponding to the intra-frame transform domain prediction value as 0.

[0185] For example, in some embodiments, if the comparison result shows that the placeholder information difference parameter is less than or equal to the second value, it is also possible to choose not to use the intra-transform domain prediction value corresponding to the current block. For example, if the placeholder information difference parameter is greater than or equal to 1 (the second value), then it can be considered that the difference between the current block and the inter-frame reference block is small. Therefore, it is possible to choose to use only the inter-frame transform domain prediction value corresponding to the current block to determine the attribute transform domain prediction value of the current block. Therefore, it is possible to choose to determine the second weight corresponding to the intra-frame transform domain prediction value as 0.

[0186] Accordingly, in the embodiments of this application, for cases where the attribute transform domain prediction value of the current block is not determined by using the intra-frame transform domain prediction value, it can be considered that only the inter-frame transform domain prediction value corresponding to the current block is used to determine the attribute transform domain prediction value of the current block. In this case, the first weight corresponding to the inter-frame transform domain prediction value can be 1.

[0187] For example, in some embodiments, the preset value may include a third value, wherein the third value may be an integer greater than or equal to 0, for example, the third value is 2.

[0188] In the embodiments of this application, when determining the first weight corresponding to the inter-frame transform domain prediction value and the second weight corresponding to the intra-frame transform domain prediction value based on the comparison result of the placeholder information difference parameter and the preset value, if the placeholder information difference parameter is greater than the third value, the first weight and the second weight are determined to be equal; if the placeholder information difference parameter is less than or equal to the third value, the ratio of the second weight to the first weight is determined to be 3.

[0189] For example, in some embodiments, the attribute transform domain prediction value of the current block can be determined by combining the inter-frame transform domain prediction value and the intra-frame transform domain prediction value corresponding to the current block. Specifically, the method for determining the attribute transform domain prediction value of the current block by combining the inter-frame transform domain prediction value and the intra-frame transform domain prediction value can be further selected based on the comparison result of the placeholder information difference parameter and the third value. For instance, if the placeholder information difference parameter is greater than the third value, then during the weighted calculation of combining the inter-frame transform domain prediction value and the intra-frame transform domain prediction value, the first weight and the second weight can be determined to be equal; if the placeholder information difference parameter is less than or equal to the third value, then during the weighted calculation of combining the inter-frame transform domain prediction value and the intra-frame transform domain prediction value, the ratio of the second weight to the first weight can be set to 3.

[0190] It is understood that, in the embodiments of this application, when the placeholder information difference parameter is greater than the third value, when determining the attribute transform domain prediction value of the current block based on the inter-frame transform domain prediction value and the intra-frame transform domain prediction value, the average of the inter-frame transform domain prediction value and the intra-frame transform domain prediction value can be directly determined as the attribute transform domain prediction value of the current block, that is, the first weight and the second weight are set to be equal.

[0191] For example, in some embodiments, if the occupancy information difference parameter is greater than 2 (the third value), then the first weight and the second weight can be set to be equal; if the occupancy information difference parameter is less than or equal to 2 (the third value), then the inter-frame transform domain prediction value and the intra-frame transform domain prediction value can be weighted according to the weight of 1 / 4 of the inter-frame transform domain prediction value and the weight of 3 / 4 of the intra-frame transform domain prediction value, that is, the ratio of the second weight to the first weight is set to 3.

[0192] For example, in some embodiments, when the comparison result is that the placeholder information difference parameter is greater than or equal to the third value, that is, when the placeholder information difference parameter is greater than or equal to 2 (the third value), it is also possible to choose to set the first weight and the second weight to be equal; correspondingly, when the comparison result is that the placeholder information difference parameter is less than the third value, that is, when the placeholder information difference parameter is less than 2 (the third value), it is also possible to choose to perform weighted calculation on the inter-frame transform domain prediction value and the intra-frame transform domain prediction value according to the weight of 1 / 4 of the inter-frame transform domain prediction value and the weight of 3 / 4 of the intra-frame transform domain prediction value, that is, to set the ratio of the second weight to the first weight to be 3.

[0193] It is understood that in the embodiments of this application, for example, the values ​​of the first value, the second value, and the third value can all be the same, all be different, or all be partially the same, and this application does not impose specific limitations. For example, the first value, the second value, and the third value can all be the same, such as all being 2; the first value, the second value, and the third value can also all be different, such as being 2, 1, and 3 respectively.

[0194] Furthermore, in the embodiments of this application, the bitstream can also be decoded to determine the attribute transformation domain residual value corresponding to the current block.

[0195] Accordingly, in the embodiments of this application, the attribute transformation domain value corresponding to the current block can also be determined based on the attribute transformation domain residual value and the attribute transformation domain prediction value of the current block.

[0196] It should be noted that, in the embodiments of this application, the attribute transformation domain value of the current block can be determined by the sum of the attribute transformation domain residual value and the attribute transformation domain predicted value of the current block.

[0197] Furthermore, in the embodiments of this application, the inter-frame transform domain prediction value, for example, the inter-frame transform domain prediction value of the inter-frame reference block, can be understood as the prediction value of the Transform Domain Inter Prediction (TDIP) or the prediction value of the Sample Domain Inter Prediction (SDIP). This application does not impose any specific limitations.

[0198] Transform Domain Inter-Frame Prediction (TDIP) is an inter-frame prediction technique performed in the transform domain (e.g., the frequency domain). TDIP first transforms the residual data of the current block (e.g., Discrete Cosine Transform, DCT), and then performs motion estimation and compensation in the transform domain. For Sample Domain Inter-Frame Prediction (SDIP), motion estimation and compensation are performed directly in the sample domain (i.e., the pixel domain).

[0199] Furthermore, in the embodiments of this application, after the decoded bitstream determines the prediction mode identifier information corresponding to the current RAHT layer, when determining the prediction mode corresponding to the current RAHT layer based on the prediction mode identifier information, if the prediction mode identifier information is a fourth value, the prediction mode corresponding to the current RAHT layer is determined according to the layer number of the current RAHT layer; if the prediction mode identifier information is a fifth value, the prediction mode corresponding to the current RAHT layer is determined to be an inter-frame prediction mode; if the prediction mode identifier information is a sixth value, the prediction transformation of the current RAHT layer is skipped.

[0200] It should be noted that, in the embodiments of this application, when determining the prediction mode corresponding to the current RAHT layer based on the prediction mode identifier information, the value of the current prediction mode identifier information can be determined first, and then the prediction mode corresponding to the current RAHT layer can be further determined based on the value of the prediction mode identifier.

[0201] For example, in some embodiments, when the prediction mode identifier information is a fourth value, it is determined that the prediction mode identifier information indicates that the current RAHT layer uses a hybrid prediction mode or an intra-frame prediction mode. Therefore, it is necessary to further determine the prediction mode corresponding to the current RAHT layer based on the number of the current RAHT layer. When the prediction mode identifier information is a fifth value, it is determined that the prediction mode identifier information indicates that the current RAHT layer uses an inter-frame prediction mode, that is, the prediction mode corresponding to the current RAHT layer is an inter-frame prediction mode. When the prediction mode identifier information is a sixth value, it is determined that the prediction mode identifier information indicates that the current RAHT layer does not perform prediction, that is, the prediction transformation of the current RAHT layer is skipped.

[0202] It should also be noted that in the embodiments of this application, the fourth, fifth, and sixth values ​​are different, and the fourth, fifth, and sixth values ​​can be in parameter form or in numerical form. Specifically, the prediction mode identification information can be a parameter written in the profile or a flag value, without specific limitations here.

[0203] For example, in the embodiments of this application, the values ​​of the fourth, fifth, and sixth values ​​are not specifically limited. For example, the fourth value can be 0, the fifth value can be 1, and the sixth value can be 2.

[0204] Furthermore, in the embodiments of this application, when determining the prediction mode corresponding to the current RAHT layer based on the number of layers of the current RAHT layer, if the number of layers of the current RAHT layer is greater than or equal to a first preset value and less than or equal to a second preset value, the prediction mode corresponding to the current RAHT layer is determined to be a hybrid prediction mode; if the number of layers of the current RAHT layer is less than the first preset value or greater than the second preset value, the prediction mode corresponding to the current RAHT layer is determined to be an intra-frame prediction mode.

[0205] It is understood that, in the embodiments of this application, the first preset value and the second preset value can be predetermined, known at both the encoding and decoding ends, and both the first preset value and the second preset value are integers greater than 0.

[0206] In summary, in this embodiment, the point cloud decoding method proposed in steps 101 to 103 above, in a hybrid prediction mode scenario, derives the attribute transform domain prediction value of the current block based on the difference between the occupancy information of the current block and the occupancy information of the inter-frame reference block. That is, in determining the attribute transform domain prediction value of the current block, the occupancy information difference parameter between the current block and the inter-frame reference block can be determined first. Then, based on this occupancy information difference parameter, combined with the inter-frame transform domain prediction value and the intra-frame transform domain prediction value corresponding to the current block, the attribute transform domain prediction value of the current block is further derived.

[0207] For example, in some embodiments, the point cloud decoding method proposed in this application specifically includes: when the placeholder information difference parameter is greater than 2, determining the intra-frame transform domain prediction value as the attribute transform domain prediction value of the current block; when the placeholder information difference parameter is greater than or equal to 1 and less than or equal to 2, determining the average of the intra-frame transform domain prediction value and the inter-frame transform domain prediction value as the attribute transform domain prediction value of the current block; otherwise, determining the inter-frame transform domain prediction value as the attribute transform domain prediction value of the current block. Experimental verification was conducted based on TMC13V27-RC2 C1, and the corresponding performance results are shown in Table 1.

[0208] Table 1

[0209] Based on Table 1, under C2 conditions, Luma, Chroma Cb, and ChromaCr can all achieve average gains of -3.3%, -2.3%, and -3.2%, respectively, with almost no impact on time complexity.

[0210] For example, in some embodiments, the point cloud decoding method proposed in this application specifically includes: when the placeholder information difference parameter is greater than 2, determining the average of the intra-frame transform domain prediction value and the inter-frame transform domain prediction value as the attribute transform domain prediction value of the current block; otherwise, setting the weight of the inter-frame transform domain prediction value to 1 / 4 and the weight of the intra-frame transform domain prediction value to 3 / 4, and then performing a weighted operation on the intra-frame transform domain prediction value and the inter-frame transform domain prediction value according to the weight of 1 / 4 of the inter-frame transform domain prediction value and the weight of 3 / 4 of the intra-frame transform domain prediction value to determine the attribute transform domain prediction value of the current block. Experimental verification was conducted based on TMC13V27-RC2 C1, and the corresponding performance results are shown in Table 2.

[0211] Table 2

[0212] Based on Table 2, under C2 conditions, Luma, Chroma Cb, and ChromaCr can all achieve average gains of -0.3%, -0.4%, and -0.2%, respectively, with almost no impact on time complexity.

[0213] Therefore, the point cloud decoding method proposed in this application takes into account the additional information of the occupancy information difference, and uses the occupancy information difference to perform weighted averaging on the mixed prediction mode, thereby improving the prediction efficiency.

[0214] This embodiment provides a point cloud decoding method. At the decoding end, when the current RAHT layer uses a hybrid prediction mode, the inter-frame reference block corresponding to the current block is determined. Based on the occupancy information of the current block and the inter-frame reference block, a occupancy information difference parameter between the current block and the inter-frame reference block is determined. Based on the occupancy information difference parameter, the attribute transform domain prediction value corresponding to the current block is determined. Therefore, in this embodiment, the difference in occupancy information between the current block and the inter-frame reference block can be determined, i.e., the occupancy information difference parameter between them can be determined. Then, in the subsequent derivation of the attribute transform domain prediction value, the occupancy information difference parameter is introduced to further determine the attribute transform domain prediction value corresponding to the current block. It is evident that the attribute transform domain prediction value in this application is determined based on the difference in occupancy information between transform blocks, which can adapt to the actual occupancy information of the transform blocks, thereby effectively improving the performance of point cloud encoding and decoding.

[0215] In another embodiment of this application, Figure 18 is a schematic diagram of the implementation process of the point cloud encoding method proposed in this application. As shown in Figure 18, the method of the encoder performing point cloud encoding may include the following steps:

[0216] Step 201: When using the hybrid prediction mode in the current RAHT layer, determine the inter-frame reference block corresponding to the current block.

[0217] In the embodiments of this application, if the current RAHT layer uses a hybrid prediction mode, the inter-frame reference block corresponding to the current block can be determined first.

[0218] It should be noted that the encoding method in this application embodiment is applied to a point cloud encoder (which may be simply referred to as an "encoder"). Specifically, this method can refer to a point cloud encoding method, or more specifically, a point cloud attribute encoding method.

[0219] It should be noted that, in the embodiments of this application, the RAHT attribute transformation is performed sequentially from the root node until the voxel level is reached. Specifically, the transformation stops when a 1×1×1 unit cube is reached, thus completing the encoding and reconstruction of the entire point cloud attributes. Here, each downsampling operation along the Z, Y, and X directions results in a RAHT transformation layer. The process continues until a 1×1×1 unit cube is reached, indicating that the voxel level has been reached.

[0220] It is understood that, in the embodiments of this application, the current RAHT layer can be a RAHT transformation layer corresponding to the current point cloud.

[0221] In the embodiments of this application, the prediction mode corresponding to the current RAHT layer can be determined first, and then the prediction mode identification information corresponding to the current RAHT layer can be determined based on the prediction mode corresponding to the current RAHT layer, and the prediction mode identification information can be written into the bit stream.

[0222] Furthermore, in the embodiments of this application, the prediction mode identification information corresponding to the current RAHT layer can be used to indicate the prediction mode used by the current RAHT layer. The prediction mode corresponding to the current RAHT layer may include inter-frame prediction mode, intra-frame prediction mode, hybrid prediction mode, and may also include skipping prediction transform.

[0223] Furthermore, in the embodiments of this application, the prediction mode corresponding to the current RAHT layer can be determined according to the rate-distortion optimization algorithm, and then the corresponding prediction mode identification information can be determined based on the prediction mode corresponding to the current RAHT layer, and the prediction mode identification information can be written into the bitstream.

[0224] It is understood that, in the embodiments of this application, when determining the prediction mode corresponding to the current RAHT layer according to the rate-distortion optimization algorithm, the first generation value corresponding to the inter-frame prediction mode, the second generation value corresponding to the intra-frame prediction mode, and the third generation value corresponding to the hybrid prediction mode can be determined according to the rate-distortion optimization algorithm, and the fourth generation value corresponding to skipping the prediction transformation can also be determined. Then, the prediction mode corresponding to the current RAHT layer can be determined based on the first generation value, the second generation value, the third generation value, and the fourth generation value.

[0225] It should be noted that, in the embodiments of this application, the prediction mode identification information corresponding to the current RAHT layer can be the syntax element corresponding to the attribute header information.

[0226] For example, in some embodiments, the prediction mode identification information can be placed in a vector array within the attribute header. Each RAHT layer corresponds to one prediction mode identification information. For instance, if the current point cloud has 10 RAHT layers, then the vector needs to contain 10 prediction mode identification information entries.

[0227] For example, in some embodiments, the prediction mode identification information can be determined by the attribute header corresponding to the slice or by the attribute header corresponding to the frame. This application does not impose specific limitations.

[0228] It is understood that, in the embodiments of this application, the current RAHT layer can be any RAHT transformation layer corresponding to the current point cloud. Accordingly, the prediction mode of the current RAHT layer can be determined by the prediction mode identification information corresponding to the current RAHT layer.

[0229] In the embodiments of this application, when it is determined that the current RAHT layer uses a hybrid prediction mode, the inter-frame reference block corresponding to the current block can be determined first.

[0230] It is understood that, in the embodiments of this application, the current block can be the transform block to be encoded in the current RAHT layer, and the inter-frame reference block corresponding to the current block can be a reconstructed transform block in the reference image corresponding to the current image that has the same or corresponding geometric information as the current block.

[0231] It should be noted that, in the embodiments of this application, the geometric information includes at least any one of the following: spatial Morton code information, spatial Hilbert code information, spatial coordinate information, spherical coordinate information, and polar coordinate information.

[0232] In other words, in the embodiments of this application, the inter-frame reference block corresponding to the current block can be a reconstructed transform block in the reference image determined based on the geometric information of the current block.

[0233] Step 202: Based on the occupancy information of the current block and the occupancy information of the inter-frame reference block, determine the occupancy information difference parameter between the current block and the inter-frame reference block.

[0234] In the embodiments of this application, if the current RAHT layer uses a hybrid prediction mode, then after determining the inter-frame reference block corresponding to the current block, the occupancy information difference parameter between the current block and the inter-frame reference block can be further determined based on the occupancy information of the current block and the occupancy information of the inter-frame reference block.

[0235] In related technologies, point cloud compression involves encoding the geometry first, followed by encoding the attributes. Therefore, when performing RAHT compression (attribute) on each current transform block, the geometric information of the point cloud slice to be encoded can be known in advance, thus allowing the determination of the transform block's placeholder information.

[0236] In other words, in this embodiment of the application, the geometric information of the nodes in the current point cloud has been fully encoded before the attribute encoding is performed in the current RAHT layer.

[0237] It is understood that, in the embodiments of this application, the occupancy information of the current block and the occupancy information of the corresponding inter-frame reference block can be further determined by the geometric information of the point cloud obtained by encoding.

[0238] In the embodiments of this application, placeholder information can be used to determine the occupancy status of the transform block. The placeholder information can be represented in binary; for example, the placeholder information can be represented by 0 or 1 to indicate the occupancy status of the transform block, where 0 represents no occupancy and 1 represents occupancy.

[0239] For example, in some embodiments, as shown in FIG15, when the RAHT transformation is performed from layer L-1 to layer L-2, the white block is not occupied, and the gray block is occupied.

[0240] For example, in some embodiments, as shown in FIG16, the occupancy status of the transform block is represented by binary using 0 or 1. Here, 0 represents no occupancy, and 1 represents occupancy; the occupancy information for transform block a is 11111111.

[0241] For example, in some embodiments, as shown in FIG17, the occupancy status of the transform block is represented by binary using 0 or 1. Here, 0 represents no occupancy, and 1 represents occupancy; the occupancy information for transform block b is 00000000.

[0242] Furthermore, in the embodiments of this application, based on the determined placeholder information of the current block and the placeholder information of the inter-frame reference block, a placeholder information difference parameter between the current block and the inter-frame reference block can be further determined. The placeholder information difference parameter can be the difference between the placeholder information of the current block and the placeholder information of the inter-frame reference block.

[0243] It is understood that in the embodiments of this application, the placeholder information difference parameter (i.e., placeholder information difference) is used to determine the number of placeholder information differences. As shown in the figure, the placeholder information difference between transform block a and transform block b is 8.

[0244] For example, in some embodiments, when determining the placeholder information difference parameter between the current block and the inter-frame reference block, assuming the placeholder information of the current block is A and the placeholder information of the inter-frame reference block is B, where A and B are both 8-bit binary numbers, the placeholder information difference parameter between the current block and the inter-frame reference block can be obtained using popcent(A∧B). Here, A∧B is a bitwise XOR operation on A and B; if the same bit is the same, the result is 0; if they are different, the result is 1. popcent() can count the number of 1s in the binary representation.

[0245] For example, in some embodiments, assuming that the placeholder information A of the current block is represented as 11111111 and the placeholder information B of the inter-frame reference block is represented as 00000000, then the placeholder information difference parameter between the current block and the inter-frame reference block can be determined by popcent(A∧B) to be 8, that is, the 8 bits of the placeholder information between the current block and the inter-frame reference block are different.

[0246] For example, in some embodiments, assuming that the placeholder information A of the current block is represented as 10001101 and the placeholder information B of the inter-frame reference block is represented as 01110011, then the placeholder information difference parameter between the current block and the inter-frame reference block can be determined by popcent(A∧B) to be 7, that is, there are 7 bits different in the placeholder information between the current block and the inter-frame reference block.

[0247] It is understood that, in the embodiments of this application, since the placeholder information is an 8-bit binary number, the placeholder information difference parameter determined based on the difference of the placeholder information can be an integer greater than or equal to 0 and less than or equal to 8.

[0248] Step 203: Determine the attribute transformation domain prediction value corresponding to the current block based on the placeholder information difference parameter.

[0249] In the embodiments of this application, after determining the occupancy information difference parameter between the current block and the inter-frame reference block based on the occupancy information of the current block and the occupancy information of the inter-frame reference block, the attribute transform domain prediction value corresponding to the current block can be further determined based on the occupancy information difference parameter.

[0250] In other words, in the embodiments of this application, for the hybrid prediction mode, when determining the attribute transform domain prediction value of the current block, the occupancy information difference parameter between the current block and the corresponding inter-frame reference block can be introduced. Specifically, for different occupancy information difference parameters, the specific process of determining the attribute transform domain prediction value of the current block through the inter-frame transform domain prediction value and / or intra-frame transform domain prediction value corresponding to the current block may also be different. That is, based on the difference in occupancy information between the current block and the intra-frame reference block, an appropriate prediction method can be adopted to obtain an appropriate prediction result (the attribute transform domain prediction value of the current block), thereby greatly improving prediction performance.

[0251] It should be noted that, in the embodiments of this application, for the hybrid prediction mode, the attribute transform domain prediction value of the current block can be determined based on the inter-frame transform domain prediction value and / or intra-frame transform domain prediction value corresponding to the current block.

[0252] Accordingly, in the embodiments of this application, the inter-frame transform domain prediction value corresponding to the current block can be determined, and / or the intra-frame transform domain prediction value corresponding to the current block can be determined.

[0253] In the embodiments of this application, the inter-frame transform domain prediction value is the attribute transform domain value of the inter-frame reference block corresponding to the current block. Since the inter-frame reference block is a reconstructed transform block, the obtained attribute transform domain value of the inter-frame reference block can be directly determined as the inter-frame transform domain prediction value corresponding to the current block.

[0254] In the embodiments of this application, the intra-transform domain prediction value is the attribute transform domain value of the intra-reference block corresponding to the current block. Since the intra-reference block is a reconstructed transform block, the obtained attribute transform domain value of the intra-reference block can be directly determined as the intra-transform domain prediction value corresponding to the current block.

[0255] Furthermore, in the embodiments of this application, when determining the attribute transform domain prediction value corresponding to the current block based on the placeholder information difference parameter, the attribute transform domain prediction value of the current block can be determined based on the placeholder information difference parameter, as well as the inter-frame transform domain prediction value and / or the intra-frame transform domain prediction value.

[0256] In the embodiments of this application, when determining the attribute transform domain prediction value of the current block based on the placeholder information difference parameter, and the inter-frame transform domain prediction value and / or intra-frame transform domain prediction value, the attribute transform domain prediction value of the current block can be determined based on the comparison result of the placeholder information difference parameter and the preset value, and the inter-frame transform domain prediction value and / or intra-frame transform domain prediction value.

[0257] In other words, in the embodiments of this application, the placeholder information difference parameter and the preset value can be compared first, and then based on the comparison result, the attribute transform domain prediction value of the current block can be determined by further combining the inter-frame transform domain prediction value and / or the intra-frame transform domain prediction value.

[0258] It is understood that, in the embodiments of this application, the placeholder information difference parameter can determine the difference between the current block and the corresponding inter-frame reference block. Accordingly, the comparison result of the placeholder information difference parameter and the preset value can determine whether to use the inter-frame transform domain prediction value to determine the attribute transform domain prediction value of the current block, or whether to use only the intra-frame transform domain prediction value to determine the attribute transform domain prediction value of the current block, or how to combine the inter-frame transform domain prediction value and the intra-frame transform domain prediction value to determine the attribute transform domain prediction value of the current block.

[0259] It is understood that in the embodiments of this application, the preset value may include one or more numerical values, wherein the preset value may be an integer greater than or equal to 0.

[0260] For example, in some embodiments, the preset value may include a first value, wherein the first value may be an integer greater than or equal to 0, for example, the first value is 2.

[0261] In the embodiments of this application, when determining the attribute transform domain prediction value of the current block based on the comparison result of the placeholder information difference parameter and the preset value, as well as the inter-frame transform domain prediction value and / or intra-frame transform domain prediction value, if the comparison result is that the placeholder information difference parameter is greater than the first value, the attribute transform domain prediction value of the current block is determined based on the intra-frame transform domain prediction value.

[0262] For example, in some embodiments, if the placeholder information difference parameter is greater than 2 (first value), it can be considered that the difference between the current block and the inter-frame reference block is large. If the attribute transform domain prediction value of the current block is determined by combining the inter-frame transform domain prediction value, there may be a problem of low prediction accuracy. Therefore, it is possible to select to use only the intra-frame transform domain prediction value corresponding to the current block to determine the attribute transform domain prediction value of the current block.

[0263] For example, in some embodiments, if the comparison result shows that the placeholder information difference parameter is greater than or equal to a first value, the attribute transform domain prediction value of the current block can also be determined based on the intra-frame transform domain prediction value. For example, if the placeholder information difference parameter is greater than or equal to 2 (the first value), then it can be considered that the difference between the current block and the inter-frame reference block is large, so the attribute transform domain prediction value of the current block can be determined by using only the intra-frame transform domain prediction value corresponding to the current block.

[0264] For example, in some embodiments, the preset value may include a first value and a second value, wherein the first value and the second value may be integers greater than or equal to 0, for example, the first value is 2 and the second value is 1.

[0265] In the embodiments of this application, when determining the attribute transform domain prediction value of the current block based on the comparison result of the placeholder information difference parameter and the preset value, as well as the inter-frame transform domain prediction value and / or intra-frame transform domain prediction value, if the comparison result is that the placeholder information difference parameter is less than or equal to the first value and greater than or equal to the second value, the attribute transform domain prediction value of the current block is determined based on the inter-frame transform domain prediction value and the intra-frame transform domain prediction value.

[0266] It is understood that, in the embodiments of this application, when the placeholder information difference parameter is less than or equal to the first value and greater than or equal to the second value, when determining the attribute transform domain prediction value of the current block based on the inter-frame transform domain prediction value and the intra-frame transform domain prediction value, the average of the inter-frame transform domain prediction value and the intra-frame transform domain prediction value can be directly determined as the attribute transform domain prediction value of the current block.

[0267] For example, in some embodiments, if the placeholder information difference parameter is greater than or equal to 1 (second value) and less than or equal to 2 (first value), then it can be considered that there is a certain degree of difference between the current block and the inter-frame reference block. If only the inter-frame transform domain prediction value is used to determine the attribute transform domain prediction value of the current block, there may be a problem of low prediction accuracy. Therefore, it is possible to combine the inter-frame transform domain prediction value and the intra-frame transform domain prediction value corresponding to the current block to determine the attribute transform domain prediction value of the current block.

[0268] For example, in some embodiments, when the placeholder information difference parameter is greater than or equal to a second value and less than a first value, the attribute transform domain prediction value of the current block can also be determined by combining the inter-frame transform domain prediction value and the intra-frame transform domain prediction value corresponding to the current block. For example, if the placeholder information difference parameter is greater than or equal to 1 (the second value) and less than 2 (the first value), then it can be considered that there is a certain degree of difference between the current block and the inter-frame reference block. Therefore, the attribute transform domain prediction value of the current block can be determined by combining the inter-frame transform domain prediction value and the intra-frame transform domain prediction value corresponding to the current block.

[0269] For example, in some embodiments, when the placeholder information difference parameter is greater than a second value and less than or equal to a first value, the attribute transform domain prediction value of the current block can also be determined by combining the inter-frame transform domain prediction value and the intra-frame transform domain prediction value corresponding to the current block. For instance, if the placeholder information difference parameter is greater than 1 (the second value) and less than or equal to 2 (the first value), then it can be considered that there is a certain degree of difference between the current block and the inter-frame reference block. Therefore, the attribute transform domain prediction value of the current block can be determined by combining the inter-frame transform domain prediction value and the intra-frame transform domain prediction value corresponding to the current block.

[0270] For example, in some embodiments, when the placeholder information difference parameter is greater than a second value and less than a first value, the attribute transform domain prediction value of the current block can also be determined by combining the inter-frame transform domain prediction value and the intra-frame transform domain prediction value corresponding to the current block. For instance, if the placeholder information difference parameter is greater than 1 (the second value) and less than 2 (the first value), then it can be considered that there is a certain degree of difference between the current block and the inter-frame reference block. Therefore, the attribute transform domain prediction value of the current block can be determined by combining the inter-frame transform domain prediction value and the intra-frame transform domain prediction value corresponding to the current block.

[0271] For example, in some embodiments, the preset value may include a second value, wherein the second value may be an integer greater than or equal to 0, for example, the second value is 1.

[0272] In the embodiments of this application, when determining the attribute transform domain prediction value of the current block based on the comparison result of the placeholder information difference parameter and the preset value, as well as the inter-frame transform domain prediction value and / or intra-frame transform domain prediction value, if the comparison result is that the placeholder information difference parameter is less than the second value, the attribute transform domain prediction value of the current block is determined based on the inter-frame transform domain prediction value.

[0273] For example, in some embodiments, if the placeholder information difference parameter is less than 1 (second value), then it can be considered that the difference between the current block and the inter-frame reference block is small and can be ignored. The attribute transform domain prediction value of the current block can be determined by using only the inter-frame transform domain prediction value to obtain a more accurate prediction result. Therefore, it is possible to select to use only the inter-frame transform domain prediction value corresponding to the current block to determine the attribute transform domain prediction value of the current block.

[0274] For example, in some embodiments, if the comparison result shows that the placeholder information difference parameter is less than or equal to a second value, the attribute transform domain prediction value of the current block can also be determined based on the inter-frame transform domain prediction value. For instance, if the placeholder information difference parameter is greater than or equal to 1 (the second value), then it can be considered that the difference between the current block and the inter-frame reference block is small, so the attribute transform domain prediction value of the current block can be determined using only the inter-frame transform domain prediction value corresponding to the current block.

[0275] For example, in some embodiments, the preset value may include a third value, wherein the third value may be an integer greater than or equal to 0, for example, the third value is 2.

[0276] In the embodiments of this application, when determining the attribute transform domain prediction value of the current block based on the comparison result of the placeholder information difference parameter and the preset value, as well as the inter-frame transform domain prediction value and / or intra-frame transform domain prediction value, if the comparison result shows that the placeholder information difference parameter is greater than the third value, the attribute transform domain prediction value of the current block is determined based on the inter-frame transform domain prediction value and the intra-frame transform domain prediction value; if the placeholder information difference parameter is less than or equal to the third value, the attribute transform domain prediction value of the current block is determined based on the preset weight parameter, the inter-frame transform domain prediction value, and the intra-frame transform domain prediction value.

[0277] For example, in some embodiments, the attribute transform domain prediction value of the current block can be determined by combining the inter-frame transform domain prediction value and the intra-frame transform domain prediction value corresponding to the current block. Specifically, the method for determining the attribute transform domain prediction value of the current block by combining the inter-frame transform domain prediction value and the intra-frame transform domain prediction value can be further selected based on the comparison result of the placeholder information difference parameter and the third value. For instance, if the placeholder information difference parameter is greater than the third value, the attribute transform domain prediction value of the current block can be directly determined based on the inter-frame transform domain prediction value and the intra-frame transform domain prediction value; if the placeholder information difference parameter is less than or equal to the third value, the weights of the inter-frame transform domain prediction value and the intra-frame transform domain prediction value can be adjusted according to a preset weight parameter to determine the attribute transform domain prediction value of the current block.

[0278] It is understood that, in the embodiments of this application, when the placeholder information difference parameter is greater than the third value, when determining the attribute transform domain prediction value of the current block based on the inter-frame transform domain prediction value and the intra-frame transform domain prediction value, the average of the inter-frame transform domain prediction value and the intra-frame transform domain prediction value can be directly determined as the attribute transform domain prediction value of the current block.

[0279] In the embodiments of this application, the preset weight parameters may include weights corresponding to inter-frame transform domain prediction values ​​and weights corresponding to intra-frame transform domain prediction values. That is, the weights corresponding to inter-frame transform domain prediction values ​​and intra-frame transform domain prediction values ​​can be preset, and then, during the weighted calculation of combining inter-frame transform domain prediction values ​​and intra-frame transform domain prediction values, the preset weight parameters can be used to control the proportion of inter-frame transform domain prediction values ​​and intra-frame transform domain prediction values.

[0280] For example, in some embodiments, the preset weight parameters can be any value greater than or equal to 0. For example, the weight corresponding to the inter-frame transform domain prediction value is 1 / 4, and the weight corresponding to the intra-frame transform domain prediction value is 3 / 4, or the weight corresponding to the inter-frame transform domain prediction value is 3 / 4, and the weight corresponding to the intra-frame transform domain prediction value is 1 / 4.

[0281] For example, in some embodiments, if the placeholder information difference parameter is greater than 2 (the third value), then the average of the inter-frame transform domain prediction value and the intra-frame transform domain prediction value can be selected as the attribute transform domain prediction value of the current block; if the placeholder information difference parameter is less than or equal to 2 (the third value), then the inter-frame transform domain prediction value and the intra-frame transform domain prediction value can be weighted according to the weight of 1 / 4 of the inter-frame transform domain prediction value and the weight of 3 / 4 of the intra-frame transform domain prediction value to finally determine the attribute transform domain prediction value of the current block.

[0282] For example, in some embodiments, when the comparison result is that the placeholder information difference parameter is greater than or equal to the third value, that is, when the placeholder information difference parameter is greater than or equal to 2 (the third value), the average value of the inter-frame transform domain prediction value and the intra-frame transform domain prediction value can be selected as the attribute transform domain prediction value of the current block. Correspondingly, when the comparison result is that the placeholder information difference parameter is less than the third value, that is, when the placeholder information difference parameter is less than 2 (the third value), the inter-frame transform domain prediction value and the intra-frame transform domain prediction value can be weighted according to the weight of 1 / 4 of the inter-frame transform domain prediction value and the weight of 3 / 4 of the intra-frame transform domain prediction value to finally determine the attribute transform domain prediction value of the current block.

[0283] It is understood that, in the embodiments of this application, for example, the values ​​of the first value, the second value, and the third value can all be the same, all be different, or all be partially the same; this application does not impose specific limitations. For example, the first value and the third value can be the same, both being 2; the first value and the second value can be different.

[0284] In the embodiments of this application, when determining the attribute transform domain prediction value of the current block based on the placeholder information difference parameter, and the inter-frame transform domain prediction value and / or intra-frame transform domain prediction value, the first weight corresponding to the inter-frame transform domain prediction value and the second weight corresponding to the intra-frame transform domain prediction value can be determined first based on the comparison result of the placeholder information difference parameter and the preset value; then the attribute transform domain prediction value of the current block can be further determined based on the first weight, the second weight, the inter-frame transform domain prediction value and the intra-frame transform domain prediction value.

[0285] In other words, in the embodiments of this application, the difference parameter of the placeholder information and the preset value can be compared first, and then the first weight corresponding to the inter-frame transform domain prediction value and the second weight corresponding to the intra-frame transform domain prediction value can be determined based on the comparison result. Then, the inter-frame transform domain prediction value and the intra-frame transform domain prediction value can be further weighted based on the first weight and the second weight to finally determine the attribute transform domain prediction value of the current block.

[0286] It is understood that in the embodiments of this application, the first weight and the second weight may be the same or different, and the first weight or the second weight may be 0. This application does not impose any specific limitations.

[0287] It is understood that in the embodiments of this application, the preset value may include one or more numerical values, wherein the preset value may be an integer greater than or equal to 0.

[0288] For example, in some embodiments, the preset value may include a first value, wherein the first value may be an integer greater than or equal to 0, for example, the first value is 2.

[0289] In the embodiments of this application, when determining the first weight corresponding to the inter-frame transform domain prediction value and the second weight corresponding to the intra-frame transform domain prediction value based on the comparison result of the placeholder information difference parameter and the preset value, if the comparison result is that the placeholder information difference parameter is greater than the first value, the first weight is determined to be 0.

[0290] For example, in some embodiments, if the occupancy information difference parameter is greater than 2 (first value), it can be considered that the difference between the current block and the inter-frame reference block is large. If the attribute transform domain prediction value of the current block is determined by combining the inter-frame transform domain prediction value, there may be a problem of low prediction accuracy. Therefore, it is possible to choose not to use the inter-frame transform domain prediction value. Thus, the first weight corresponding to the inter-frame transform domain prediction value can be determined to be 0.

[0291] For example, in some embodiments, if the comparison result shows that the placeholder information difference parameter is greater than or equal to a first value, it is also possible to choose not to use the inter-frame transform domain prediction value to determine the attribute transform domain prediction value of the current block. For example, if the placeholder information difference parameter is greater than or equal to 2 (the first value), then it can be considered that the difference between the current block and the inter-frame reference block is large, so it is possible to choose to determine the first weight corresponding to the inter-frame transform domain prediction value as 0.

[0292] Accordingly, in the embodiments of this application, for cases where the inter-frame transform domain prediction value is not used to determine the attribute transform domain prediction value of the current block, it can be considered that only the intra-frame transform domain prediction value corresponding to the current block is used to determine the attribute transform domain prediction value of the current block. In this case, the second weight corresponding to the intra-frame transform domain prediction value can be 1.

[0293] For example, in some embodiments, the preset value may include a first value and a second value, wherein the first value and the second value may be integers greater than or equal to 0, for example, the first value is 2 and the second value is 1.

[0294] In the embodiments of this application, when determining the first weight corresponding to the inter-frame transform domain prediction value and the second weight corresponding to the intra-frame transform domain prediction value based on the comparison result of the placeholder information difference parameter and the preset value, if the comparison result is that the placeholder information difference parameter is less than or equal to the first value and greater than or equal to the second value, the first weight and the second weight are determined to be equal.

[0295] It is understood that, in the embodiments of this application, when the placeholder information difference parameter is less than or equal to the first value and greater than or equal to the second value, the average of the inter-frame transform domain prediction value and the intra-frame transform domain prediction value can be selected as the attribute transform domain prediction value of the current block. Therefore, the first weight and the second weight can be set to be equal.

[0296] For example, in some embodiments, if the placeholder information difference parameter is greater than or equal to 1 (second value) and less than or equal to 2 (first value), then it can be considered that there is a certain degree of difference between the current block and the inter-frame reference block. The attribute transform domain prediction value of the current block can be determined by combining the inter-frame transform domain prediction value and the intra-frame transform domain prediction value corresponding to the current block. For example, the first weight and the second weight can be set to be equal. For example, the first weight and the second weight are both 1 / 2.

[0297] For example, in some embodiments, when the placeholder information difference parameter is greater than or equal to the second value and less than the first value, it is also possible to determine that the first weight and the second weight are equal. For example, if the placeholder information difference parameter is greater than or equal to 1 (the second value) and less than 2 (the first value), then it can be considered that there is a certain degree of difference between the current block and the inter-frame reference block. Therefore, it is possible to combine the inter-frame transform domain prediction value and the intra-frame transform domain prediction value corresponding to the current block to determine the attribute transform domain prediction value of the current block. For example, the first weight and the second weight are both determined to be 1 / 2.

[0298] For example, in some embodiments, when the placeholder information difference parameter is greater than a second value and less than or equal to a first value, it is also possible to determine that the first weight and the second weight are equal. For example, if the placeholder information difference parameter is greater than 1 (the second value) and less than or equal to 2 (the first value), then it can be considered that there is a certain degree of difference between the current block and the inter-frame reference block. Therefore, it is possible to combine the inter-frame transform domain prediction value and the intra-frame transform domain prediction value corresponding to the current block to determine the attribute transform domain prediction value of the current block. For example, the first weight and the second weight are both determined to be 1 / 2.

[0299] For example, in some embodiments, when the placeholder information difference parameter is greater than a second value and less than a first value, it is also possible to determine that the first weight and the second weight are equal. For example, if the placeholder information difference parameter is greater than 1 (the second value) and less than 2 (the first value), then it can be considered that there is a certain degree of difference between the current block and the inter-frame reference block. Therefore, it is possible to combine the inter-frame transform domain prediction value and the intra-frame transform domain prediction value corresponding to the current block to determine the attribute transform domain prediction value of the current block. For example, the first weight and the second weight are both determined to be 1 / 2.

[0300] For example, in some embodiments, the preset value may include a second value, wherein the second value may be an integer greater than or equal to 0, for example, the second value is 1.

[0301] In the embodiments of this application, when determining the first weight corresponding to the inter-frame transform domain prediction value and the second weight corresponding to the intra-frame transform domain prediction value based on the comparison result of the placeholder information difference parameter and the preset value, the second weight is determined to be 0 if the placeholder information difference parameter is less than the second value.

[0302] For example, in some embodiments, if the placeholder information difference parameter is less than 1 (second value), then it can be considered that the difference between the current block and the inter-frame reference block is small and can be ignored. Only the inter-frame transform domain prediction value is used to determine the attribute transform domain prediction value of the current block to obtain a more accurate prediction result. Therefore, it is possible to choose not to use the intra-frame transform domain prediction value corresponding to the current block. Therefore, it is possible to choose to determine the second weight corresponding to the intra-frame transform domain prediction value as 0.

[0303] For example, in some embodiments, if the comparison result shows that the placeholder information difference parameter is less than or equal to the second value, it is also possible to choose not to use the intra-transform domain prediction value corresponding to the current block. For example, if the placeholder information difference parameter is greater than or equal to 1 (the second value), then it can be considered that the difference between the current block and the inter-frame reference block is small. Therefore, it is possible to choose to use only the inter-frame transform domain prediction value corresponding to the current block to determine the attribute transform domain prediction value of the current block. Therefore, it is possible to choose to determine the second weight corresponding to the intra-frame transform domain prediction value as 0.

[0304] Accordingly, in the embodiments of this application, for cases where the attribute transform domain prediction value of the current block is not determined by using the intra-frame transform domain prediction value, it can be considered that only the inter-frame transform domain prediction value corresponding to the current block is used to determine the attribute transform domain prediction value of the current block. In this case, the first weight corresponding to the inter-frame transform domain prediction value can be 1.

[0305] For example, in some embodiments, the preset value may include a third value, wherein the third value may be an integer greater than or equal to 0, for example, the third value is 2.

[0306] In the embodiments of this application, when determining the first weight corresponding to the inter-frame transform domain prediction value and the second weight corresponding to the intra-frame transform domain prediction value based on the comparison result of the placeholder information difference parameter and the preset value, if the placeholder information difference parameter is greater than the third value, the first weight and the second weight are determined to be equal; if the placeholder information difference parameter is less than or equal to the third value, the ratio of the second weight to the first weight is determined to be 3.

[0307] For example, in some embodiments, the attribute transform domain prediction value of the current block can be determined by combining the inter-frame transform domain prediction value and the intra-frame transform domain prediction value corresponding to the current block. Specifically, the method for determining the attribute transform domain prediction value of the current block by combining the inter-frame transform domain prediction value and the intra-frame transform domain prediction value can be further selected based on the comparison result of the placeholder information difference parameter and the third value. For instance, if the placeholder information difference parameter is greater than the third value, then during the weighted calculation of combining the inter-frame transform domain prediction value and the intra-frame transform domain prediction value, the first weight and the second weight can be determined to be equal; if the placeholder information difference parameter is less than or equal to the third value, then during the weighted calculation of combining the inter-frame transform domain prediction value and the intra-frame transform domain prediction value, the ratio of the second weight to the first weight can be set to 3.

[0308] It is understood that, in the embodiments of this application, when the placeholder information difference parameter is greater than the third value, when determining the attribute transform domain prediction value of the current block based on the inter-frame transform domain prediction value and the intra-frame transform domain prediction value, the average of the inter-frame transform domain prediction value and the intra-frame transform domain prediction value can be directly determined as the attribute transform domain prediction value of the current block, that is, the first weight and the second weight are set to be equal.

[0309] For example, in some embodiments, if the occupancy information difference parameter is greater than 2 (the third value), then the first weight and the second weight can be set to be equal; if the occupancy information difference parameter is less than or equal to 2 (the third value), then the inter-frame transform domain prediction value and the intra-frame transform domain prediction value can be weighted according to the weight of 1 / 4 of the inter-frame transform domain prediction value and the weight of 3 / 4 of the intra-frame transform domain prediction value, that is, the ratio of the second weight to the first weight is set to 3.

[0310] For example, in some embodiments, when the comparison result is that the placeholder information difference parameter is greater than or equal to the third value, that is, when the placeholder information difference parameter is greater than or equal to 2 (the third value), it is also possible to choose to set the first weight and the second weight to be equal; correspondingly, when the comparison result is that the placeholder information difference parameter is less than the third value, that is, when the placeholder information difference parameter is less than 2 (the third value), it is also possible to choose to perform weighted calculation on the inter-frame transform domain prediction value and the intra-frame transform domain prediction value according to the weight of 1 / 4 of the inter-frame transform domain prediction value and the weight of 3 / 4 of the intra-frame transform domain prediction value, that is, to set the ratio of the second weight to the first weight to be 3.

[0311] It is understood that in the embodiments of this application, for example, the values ​​of the first value, the second value, and the third value can all be the same, all be different, or all be partially the same, and this application does not impose specific limitations. For example, the first value, the second value, and the third value can all be the same, such as all being 2; the first value, the second value, and the third value can also all be different, such as being 2, 1, and 3 respectively.

[0312] Furthermore, in the embodiments of this application, the attribute transformation domain residual value corresponding to the current block can also be determined based on the predicted value of the attribute transformation domain of the current block and the true value of the attribute transformation domain of the current block.

[0313] It should be noted that, in the embodiments of this application, the residual value of the attribute transformation domain corresponding to the current block can be determined by the difference between the true value of the attribute transformation domain of the current block and the predicted value of the attribute transformation domain of the current block.

[0314] Furthermore, in the embodiments of this application, the attribute transformation domain residual value can also be written into the bitstream.

[0315] Furthermore, in the embodiments of this application, the inter-frame transform domain prediction value, for example, the inter-frame transform domain prediction value of the inter-frame reference block, can be understood as the prediction value of transform domain inter-frame prediction (TDIP) or the prediction value of sample domain inter-frame prediction (SDIP). This application does not impose any specific limitations.

[0316] Transform Domain Inter-Frame Prediction (TDIP) is an inter-frame prediction technique performed in the transform domain (e.g., the frequency domain). TDIP first transforms the residual data of the current block (e.g., Discrete Cosine Transform, DCT), and then performs motion estimation and compensation in the transform domain. For Sample Domain Inter-Frame Prediction (SDIP), motion estimation and compensation are performed directly in the sample domain (i.e., the pixel domain).

[0317] Furthermore, in the embodiments of this application, the first-generation value corresponding to the inter-frame prediction mode, the second-generation value corresponding to the intra-frame prediction mode, and the hybrid prediction mode are determined respectively according to the rate-distortion optimization algorithm. After determining the prediction mode of the current RAHT layer based on the first, second, third, and fourth generation values, if the first generation value is less than the second, third, and fourth generation values, the prediction mode of the current RAHT layer can be determined as an inter-frame prediction mode, and the prediction mode identifier information can be determined to be the fifth value. If the second generation value is less than the first, third, and fourth generation values, the prediction mode of the current RAHT layer can be determined as an intra-frame prediction mode, and the prediction mode identifier information can be determined to be the fourth value. If the third generation value is less than the first, second, and fourth generation values, the prediction mode of the current RAHT layer can be determined as an intra-frame prediction mode, and the prediction mode identifier information can be determined to be the fourth value. If the fourth generation value is less than the first, second, and third generation values, the prediction transformation of the current RAHT layer can be skipped, and the prediction mode identifier information can be determined to be the sixth value.

[0318] It should also be noted that in the embodiments of this application, the fourth, fifth, and sixth values ​​are different, and the fourth, fifth, and sixth values ​​can be in parameter form or in numerical form. Specifically, the prediction mode identification information can be a parameter written in the profile or a flag value, without specific limitations here.

[0319] For example, in the embodiments of this application, the values ​​of the fourth, fifth, and sixth values ​​are not specifically limited. For example, the fourth value can be 0, the fifth value can be 1, and the sixth value can be 2.

[0320] In summary, in this embodiment, the point cloud coding method proposed in steps 201 to 203 above, in a hybrid prediction mode scenario, selects to derive the attribute transform domain prediction value of the current block based on the difference between the occupancy information of the current block and the occupancy information of the inter-frame reference block. That is, in determining the attribute transform domain prediction value of the current block, the occupancy information difference parameter between the current block and the inter-frame reference block can be determined first. Then, based on this occupancy information difference parameter, combined with the inter-frame transform domain prediction value and the intra-frame transform domain prediction value corresponding to the current block, the attribute transform domain prediction value of the current block is further derived.

[0321] For example, in some embodiments, the point cloud coding method proposed in this application is adopted, specifically including: when the placeholder information difference parameter is greater than 2, the intra-frame transform domain prediction value is determined as the attribute transform domain prediction value of the current block; when the placeholder information difference parameter is greater than or equal to 1 and less than or equal to 2, the average value of the intra-frame transform domain prediction value and the inter-frame transform domain prediction value is determined as the attribute transform domain prediction value of the current block; otherwise, the inter-frame transform domain prediction value is determined as the attribute transform domain prediction value of the current block. Experimental verification was conducted based on TMC13V27-RC2 C1, and the corresponding performance results are shown in Table 1.

[0322] Based on Table 1, under C2 conditions, Luma, Chroma Cb, and ChromaCr can all achieve average gains of -3.3%, -2.3%, and -3.2%, respectively, with almost no impact on time complexity.

[0323] For example, in some embodiments, the point cloud encoding method proposed in this application is adopted, specifically including: when the placeholder information difference parameter is greater than 2, the average value of the intra-frame transform domain prediction value and the inter-frame transform domain prediction value is determined as the attribute transform domain prediction value of the current block; otherwise, the weight of the inter-frame transform domain prediction value is set to 1 / 4, and the weight of the intra-frame transform domain prediction value is set to 3 / 4. Then, the intra-frame transform domain prediction value and the inter-frame transform domain prediction value are weighted according to the weight of 1 / 4 of the inter-frame transform domain prediction value and the weight of 3 / 4 of the intra-frame transform domain prediction value to determine the attribute transform domain prediction value of the current block. Experimental verification was performed based on TMC13V27-RC2 C1, and the corresponding performance results are shown in Table 2.

[0324] Based on Table 2, under C2 conditions, Luma, Chroma Cb, and ChromaCr can all achieve average gains of -0.3%, -0.4%, and -0.2%, respectively, with almost no impact on time complexity.

[0325] Therefore, the point cloud encoding method proposed in this application takes into account the additional information of the occupancy information difference, and uses the occupancy information difference to perform weighted averaging on the mixed prediction mode, thereby improving the prediction efficiency.

[0326] This embodiment provides a point cloud encoding method. At the encoding end, when the current RAHT layer uses a hybrid prediction mode, the inter-frame reference block corresponding to the current block is determined. Based on the occupancy information of the current block and the inter-frame reference block, a occupancy information difference parameter between the current block and the inter-frame reference block is determined. Based on the occupancy information difference parameter, the attribute transform domain prediction value corresponding to the current block is determined. Therefore, in this embodiment, the difference in occupancy information between the current block and the inter-frame reference block can be determined, i.e., the occupancy information difference parameter between them can be determined. Then, in the subsequent derivation of the attribute transform domain prediction value, the occupancy information difference parameter is introduced to further determine the attribute transform domain prediction value corresponding to the current block. It is evident that the attribute transform domain prediction value in this application is determined based on the difference in occupancy information between transform blocks, which can adapt to the actual occupancy information of the transform blocks, thereby effectively improving the performance of point cloud encoding and decoding.

[0327] Based on the above embodiments, this application proposes a point cloud encoding and decoding method. In the process of determining the predicted value of the attribute transformation domain, the method takes into account the additional information of the occupancy information difference (occupancy information difference parameter). At the same time, the occupancy information difference can also be used to adjust and control the weight value in the hybrid prediction mode, which further improves the encoding and decoding performance and enhances the prediction efficiency.

[0328] In the embodiments of this application, as shown in FIG12, in the related art, when the inter-frame reference block corresponding to the current block is available, for the hybrid prediction mode, the attribute transform domain prediction value corresponding to the previous block can be determined by simply averaging the intra-frame transform domain prediction value and the inter-frame transform domain prediction value.

[0329] In the embodiments of this application, Figure 19 is a schematic diagram of the placeholder information difference proposed in the embodiments of this application. As shown in Figure 19, when the inter-frame reference block corresponding to the current block is available, the placeholder information of the current block and the placeholder information of the inter-frame reference block are not necessarily consistent. If the difference between the two placeholder information is large, the prediction result obtained by using the inter-frame transform domain prediction value to derive the attribute transform domain prediction value may be inaccurate. In this case, if only the intra-frame transform domain prediction value and the inter-frame transform domain prediction value are simply averaged to determine the attribute transform domain prediction value corresponding to the previous block, it will lead to the defect of poor prediction effect.

[0330] In the embodiments of this application, when deriving the attribute transform domain prediction value, the occupancy information difference can be introduced as a factor. The occupancy information difference can also be used to adjust the proportion of intra-frame transform domain prediction value and inter-frame transform domain prediction value in the weighted averaging process, thereby further improving the prediction performance.

[0331] It is understood that the encoding and decoding method proposed in the embodiments of this application can be applied to the case of hybrid prediction mode.

[0332] For example, in some embodiments, the method for determining the attribute transform domain prediction value using placeholder information difference may include method one and method two.

[0333] Method 1: When the current block is in hybrid prediction mode, for the transform block to be decoded at level lvl of the transform tree, search for a reference transform block (reference transform block) at level lvl in the reference transform tree that has the same geometric spatial coordinates; this is the inter-frame reference block. If such a reference transform block is found, its transform coefficients are the inter-frame prediction values ​​(inter-frame transform domain prediction values), meaning the attribute transform domain value of the obtained inter-frame reference block is determined as the inter-frame transform domain prediction value corresponding to the current block. Simultaneously, if such a reference transform block exists, continue to compare the placeholder information of the current transform block and the reference transform block, and calculate the placeholder information difference. Use the neighborhood information of the current transform block to obtain the intra-frame prediction value (intra-frame transform domain prediction value), meaning the attribute transform domain value of the obtained intra-frame reference block is determined as the inter-frame transform domain prediction value for the current block. The corresponding intra-frame transform domain prediction value; if the placeholder information difference > 2, then the predicted value of the transform coefficients of the current transform block is the intra-frame prediction value, that is, the attribute transform domain prediction value of the current block is determined based on the intra-frame transform domain prediction value; if 1 <= placeholder information difference <= 2, then the predicted value of the transform coefficients of the current transform block is the average of the inter-frame prediction value and the intra-frame prediction value, that is, the attribute transform domain prediction value of the current block is determined based on the inter-frame transform domain prediction value and the intra-frame transform domain prediction value; otherwise, the predicted value of the transform coefficients of the current transform block is the inter-frame prediction value, that is, the attribute transform domain prediction value of the current block is determined based on the inter-frame transform domain prediction value.

[0334] For example, in some embodiments, the scheme of method one was experimentally verified based on tmc13v27-rc2 C1, and the corresponding performance results are shown in Table 1. Based on Table 1, it can be seen that under C2 conditions, Luma, Chroma Cb, and ChromaCr can all achieve average gains of -3.3%, -2.3%, and -3.2%, respectively, with almost no impact on time complexity.

[0335] Method 2: When the current block is in hybrid prediction mode, for the transform block to be decoded at the current level 1 of the transform tree, search for a reference transform block at level 1 with the same geometric spatial coordinates in the reference transform tree; this is the inter-frame reference block. If such a reference transform block is found, its transform coefficients are the inter-frame prediction values ​​(inter-frame transform domain prediction values), that is, the attribute transform domain value of the obtained inter-frame reference block is determined as the inter-frame transform domain prediction value corresponding to the current block. Simultaneously, if such a reference transform block exists, continue to compare the placeholder information of the current transform block and the reference transform block, and calculate the placeholder information difference. Use the neighborhood information of the current transform block to obtain the intra-frame prediction value (intra-frame transform domain prediction value), that is, determine the attribute transform domain value of the obtained intra-frame reference block as the intra-frame prediction value corresponding to the current block. Domain prediction value; if the occupancy information difference > 2, then the predicted value of the transform coefficients of the current transform block is the average of the inter-frame prediction value and the intra-frame prediction value, that is, the attribute transform domain prediction value of the current block is determined based on the inter-frame transform domain prediction value and the intra-frame transform domain prediction value; otherwise, the predicted value of the transform coefficients of the current transform block = inter-frame prediction value * 1 / 4 + intra-frame prediction value * 3 / 4, that is, the attribute transform domain prediction value of the current block is determined based on the preset weight parameters, the inter-frame transform domain prediction value and the intra-frame transform domain prediction value, where the preset weight parameters include the weight 1 / 4 of the inter-frame prediction value and the weight 3 / 4 of the intra-frame prediction value.

[0336] For example, in some embodiments, the scheme of method two was experimentally verified based on tmc13v27-rc2 C1, and the corresponding performance results are shown in Table 2. Based on Table 2, it can be seen that under C2 conditions, Luma, Chroma Cb, and ChromaCr can all achieve average gains of -0.3%, -0.4%, and -0.2%, respectively, with almost no impact on time complexity.

[0337] In summary, the point cloud encoding and decoding method proposed in this application takes into account the additional information of the occupancy information difference, and uses the occupancy information difference to perform weighted averaging on the mixed prediction mode, which can adapt to the real occupancy information of the transform block, thereby effectively improving the performance of point cloud encoding and decoding.

[0338] In another embodiment of this application, based on the same inventive concept as the foregoing embodiments, FIG20 is a schematic diagram of the composition structure of an encoder proposed in an embodiment of this application. As shown in FIG20, the encoder 100 may include: a first determining unit 111; wherein,

[0339] The first determining unit 111 is configured to, when using the hybrid prediction mode in the current RAHT layer, determine the inter-frame reference block corresponding to the current block; determine the occupancy information difference parameter between the current block and the inter-frame reference block based on the occupancy information of the current block and the occupancy information of the inter-frame reference block; and determine the attribute transform domain prediction value corresponding to the current block based on the occupancy information difference parameter.

[0340] It should be noted that, in the embodiments of this application, encoder 100 can also be regarded as a data processing mode (or "entropy encoder"), used to encode the values ​​of the syntax elements to be encoded.

[0341] Understandably, in the embodiments of this application, a "unit" can be a portion of a circuit, a portion of a processor, a portion of a program or software, etc., and can also be a module or a non-modular component. Furthermore, the components in this embodiment can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit described above can be implemented in hardware or as a software functional module.

[0342] If the integrated unit is implemented as a software functional module and not sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this embodiment, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) or processor to execute all or part of the steps of the method described in this embodiment. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0343] Therefore, this application provides a computer-readable storage medium applied to an encoder 100, the computer-readable storage medium storing a computer program that, when executed by a first processor, implements the encoding method described in any of the foregoing embodiments.

[0344] Based on the composition of the encoder 100 described above and the computer-readable storage medium, Figure 21 is a schematic diagram of the composition structure of an encoder according to an embodiment of this application. As shown in Figure 21, the encoder 100 may include: a first memory 121 and a first processor 122, a first communication interface 123, and a first bus system 124. The first memory 121, the first processor 122, and the first communication interface 123 are coupled together through the first bus system 124. It can be understood that the first bus system 124 is used to realize the connection and communication between these components. In addition to the data bus, the first bus system 124 also includes a power bus, a control bus, and a status signal bus. However, for clarity, all buses are labeled as the first bus system 124.

[0345] The first communication interface 123 is used for receiving and sending signals during the process of sending and receiving information with other external network elements;

[0346] The first memory 121 is used to store computer programs that can run on the first processor;

[0347] The first processor 122 is configured to, when running the computer program, determine the inter-frame reference block corresponding to the current block when the current RAHT layer uses a hybrid prediction mode; determine the occupancy information difference parameter between the current block and the inter-frame reference block based on the occupancy information of the current block and the occupancy information of the inter-frame reference block; and determine the attribute transform domain prediction value corresponding to the current block based on the occupancy information difference parameter.

[0348] It is understood that the first memory 121 in the embodiments of this application can be volatile memory or non-volatile memory, or may include both volatile and non-volatile memory. The non-volatile memory can be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. The volatile memory can be random access memory (RAM), which is used as an external cache. By way of example, but not limitation, many forms of RAM are available, such as Static Random Access Memory (SRAM), Dynamic Random Access Memory (DRAM), Synchronous DRAM (SDRAM), Double Data Rate SDRAM (DDRSDRAM), Enhanced Synchronous DRAM (ESDRAM), Synchlink DRAM (SLDRAM), and Direct Rambus RAM (DRRAM). The first memory 121 of the systems and methods described in this application is intended to include, but is not limited to, these and any other suitable types of memory.

[0349] The first processor 122 may be an integrated circuit chip with signal processing capabilities. In implementation, each step of the above method can be completed by the integrated logic circuitry in the hardware of the first processor 122 or by instructions in software form. The first processor 122 may be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. It can implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of this application. The general-purpose processor may be a microprocessor or any conventional processor. The steps of the methods disclosed in the embodiments of this application can be directly embodied in the execution of a hardware decoding processor, or executed by a combination of hardware and software modules in the decoding processor. The software modules may reside in random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, or other mature storage media in the art. The storage medium is located in the first memory 121. The first processor 122 reads the information in the first memory 121 and completes the steps of the above method in conjunction with its hardware.

[0350] It is understood that the embodiments described in this application can be implemented using hardware, software, firmware, middleware, microcode, or a combination thereof. For hardware implementation, the processing unit can be implemented in one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), general-purpose processors, controllers, microcontrollers, microprocessors, other electronic units for performing the functions described in this application, or combinations thereof. For software implementation, the technology described in this application can be implemented through modules (e.g., procedures, functions, etc.) that perform the functions described in this application. Software code can be stored in memory and executed by a processor. The memory can be implemented in the processor or external to the processor.

[0351] Alternatively, as another embodiment, the first processor 122 is further configured to perform the method described in any of the foregoing embodiments when running the computer program.

[0352] This embodiment provides an encoder that takes into account the additional information of the occupancy information difference and uses the occupancy information difference to perform a weighted average of the mixed prediction modes, which can adapt to the real occupancy information of the transform block, thereby effectively improving the performance of point cloud encoding and decoding.

[0353] In another embodiment of this application, based on the same inventive concept as the foregoing embodiments, FIG22 is a schematic diagram of the composition structure of a decoder proposed in an embodiment of this application. As shown in FIG22, the decoder 200 may include: a second determining unit 211; wherein,

[0354] The second determining unit 211 is configured to, when using the hybrid prediction mode in the current RAHT layer, determine the inter-frame reference block corresponding to the current block; determine the occupancy information difference parameter between the current block and the inter-frame reference block based on the occupancy information of the current block and the occupancy information of the inter-frame reference block; and determine the attribute transform domain prediction value corresponding to the current block based on the occupancy information difference parameter.

[0355] It should be noted that, in the embodiments of this application, the decoder 200 can also be regarded as a data processing mode (or "entropy decoder"), which is used to decode the values ​​of the syntax elements to be decoded.

[0356] Understandably, in this embodiment, a "unit" can be a portion of a circuit, a portion of a processor, a portion of a program or software, etc., and can also be a module or a non-modular component. Furthermore, the components in this embodiment can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional module.

[0357] If the integrated unit is implemented as a software functional module and is not sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, this embodiment provides a computer-readable storage medium applied to the decoder 200. This computer-readable storage medium stores a computer program, which, when executed by a second processor, implements the method described in any of the foregoing embodiments.

[0358] Based on the composition of the decoder 200 and the computer-readable storage medium described above, Figure 23 is a schematic diagram of the composition structure of a decoder according to an embodiment of this application. As shown in Figure 23, the decoder 200 may include: a second memory 221 and a second processor 222, a second communication interface 223, and a second bus system 224. The second memory 221, the second processor 222, and the second communication interface 223 are coupled together through the second bus system 224. It is understood that the second bus system 224 is used to realize the connection and communication between these components. In addition to a data bus, the second bus system 224 also includes a power bus, a control bus, and a status signal bus. However, for clarity, all buses are labeled as the second bus system 224.

[0359] The second communication interface 223 is used for receiving and sending signals during the process of sending and receiving information with other external network elements;

[0360] The second memory 221 is used to store computer programs that can run on the second processor;

[0361] The second processor 222 is configured to, when running the computer program, determine the inter-frame reference block corresponding to the current block when the current RAHT layer uses a hybrid prediction mode; determine the occupancy information difference parameter between the current block and the inter-frame reference block based on the occupancy information of the current block and the occupancy information of the inter-frame reference block; and determine the attribute transform domain prediction value corresponding to the current block based on the occupancy information difference parameter.

[0362] It is understood that the second memory 221 in the embodiments of this application can be volatile memory or non-volatile memory, or may include both volatile and non-volatile memory. The non-volatile memory can be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. The volatile memory can be random access memory (RAM), which is used as an external cache. By way of example, but not limitation, many forms of RAM are available, such as Static Random Access Memory (SRAM), Dynamic Random Access Memory (DRAM), Synchronous DRAM (SDRAM), Double Data Rate SDRAM (DDRSDRAM), Enhanced Synchronous DRAM (ESDRAM), Synchlink DRAM (SLDRAM), and Direct Rambus RAM (DRRAM). The second memory 221 of the systems and methods described in this application is intended to include, but is not limited to, these and any other suitable types of memory.

[0363] The second processor 222 may be an integrated circuit chip with signal processing capabilities. In implementation, each step of the above method can be completed by the integrated logic circuitry in the hardware of the second processor 222 or by instructions in software form. The second processor 222 can be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. It can implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of this application. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the methods disclosed in the embodiments of this application can be directly embodied in the execution of a hardware decoding processor, or can be executed by a combination of hardware and software modules in the decoding processor. The software modules can be located in random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, or other mature storage media in the art. The storage medium is located in the second memory 221. The second processor 222 reads the information in the second memory 221 and, in conjunction with its hardware, completes the steps of the above method.

[0364] It is understood that the embodiments described in this application can be implemented using hardware, software, firmware, middleware, microcode, or a combination thereof. For hardware implementation, the processing unit can be implemented in one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), general-purpose processors, controllers, microcontrollers, microprocessors, other electronic units for performing the functions described in this application, or combinations thereof. For software implementation, the technology described in this application can be implemented through modules (e.g., procedures, functions, etc.) that perform the functions described in this application. Software code can be stored in memory and executed by a processor. The memory can be implemented in the processor or external to the processor.

[0365] Alternatively, as another embodiment, the second processor 222 is also configured to perform the method described in any of the foregoing embodiments when running the computer program.

[0366] This embodiment provides a decoder that takes into account the additional information of the placeholder information difference, and uses the placeholder information difference to perform weighted averaging of the mixed prediction mode, which can adapt to the real placeholder information of the transform block, thereby effectively improving the performance of point cloud encoding and decoding.

[0367] Furthermore, embodiments of this application also propose a bitstream, wherein the bitstream is generated by bit encoding based on information to be encoded; wherein the information to be encoded includes at least:

[0368] Attribute transformation domain residual value, prediction mode identification information.

[0369] Furthermore, this embodiment provides a computer-readable storage medium for storing a bitstream generated by any of the encoding methods in the foregoing embodiments.

[0370] It should be noted that, in this application, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0371] The sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0372] The methods disclosed in the several method embodiments provided in this application can be arbitrarily combined without conflict to obtain new method embodiments.

[0373] The features disclosed in the several product embodiments provided in this application can be arbitrarily combined without conflict to obtain new product embodiments.

[0374] The features disclosed in the several method or device embodiments provided in this application can be arbitrarily combined without conflict to obtain new method or device embodiments.

[0375] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims. Industrial applicability

[0376] This application provides a point cloud encoding / decoding method, a bitstream, an encoder, a decoder, and a storage medium. When the encoding / decoding end uses a hybrid prediction mode in the current RAHT layer, it determines the inter-frame reference block corresponding to the current block; based on the occupancy information of the current block and the inter-frame reference block, it determines the occupancy information difference parameter between the current block and the inter-frame reference block; and based on the occupancy information difference parameter, it determines the attribute transform domain prediction value corresponding to the current block. Therefore, in this application's embodiments, the difference in occupancy information between the current block and the inter-frame reference block can be determined, i.e., the occupancy information difference parameter between them can be determined. Then, in the subsequent derivation of the attribute transform domain prediction value, the occupancy information difference parameter is introduced to further determine the attribute transform domain prediction value corresponding to the current block. It is evident that the attribute transform domain prediction value in this application is determined based on the difference in occupancy information between transform blocks, which can adapt to the actual occupancy information of the transform blocks, thereby effectively improving the performance of point cloud encoding / decoding.

Claims

A point cloud decoding method, applied to a decoder, the method comprising: When the RAHT layer of the current region adaptive hierarchical transformation uses the hybrid prediction mode, determine the inter-frame reference block corresponding to the current block; Based on the occupancy information of the current block and the occupancy information of the inter-frame reference block, determine the occupancy information difference parameter between the current block and the inter-frame reference block; The attribute transformation domain prediction value corresponding to the current block is determined based on the placeholder information difference parameter. The method of claim 1, wherein, The method further includes: Determine the inter-frame transform domain prediction value corresponding to the current block, and / or determine the intra-frame transform domain prediction value corresponding to the current block. The method of claim 2, wherein, The step of determining the attribute transform domain prediction value corresponding to the current block based on the occupancy information difference parameter includes: Based on the occupancy information difference parameter, and the inter-frame transform domain prediction value and / or the intra-frame transform domain prediction value, the attribute transform domain prediction value of the current block is determined. The method of claim 3, wherein, The step of determining the attribute transform domain prediction value of the current block based on the occupancy information difference parameter, the inter-frame transform domain prediction value, and / or the intra-frame transform domain prediction value includes: Based on the comparison results of the occupancy information difference parameters and preset values, as well as the inter-frame transform domain prediction value and / or the intra-frame transform domain prediction value, the attribute transform domain prediction value of the current block is determined. The method of claim 4, wherein, The preset value includes a first value. The determination of the attribute transform domain prediction value of the current block based on the comparison result between the occupancy information difference parameter and the preset value, and the inter-frame transform domain prediction value and / or the intra-frame transform domain prediction value, includes: If the comparison result shows that the placeholder information difference parameter is greater than the first value, the attribute transform domain prediction value of the current block is determined based on the intra-frame transform domain prediction value. The method of claim 4, wherein, The preset value includes a first value and a second value. The determination of the attribute transform domain prediction value of the current block based on the comparison result of the occupancy information difference parameter and the preset value, and the inter-frame transform domain prediction value and / or the intra-frame transform domain prediction value, includes: If the comparison result is that the placeholder information difference parameter is less than or equal to the first value and greater than or equal to the second value, the attribute transform domain prediction value of the current block is determined based on the inter-frame transform domain prediction value and the intra-frame transform domain prediction value. The method of claim 4, wherein, The preset value includes a second value. The determination of the attribute transform domain prediction value of the current block based on the comparison result of the occupancy information difference parameter and the preset value, and the inter-frame transform domain prediction value and / or the intra-frame transform domain prediction value, includes: If the comparison result shows that the occupancy information difference parameter is less than the second value, the attribute transform domain prediction value of the current block is determined based on the inter-frame transform domain prediction value. The method of claim 4, wherein, The preset value includes a third value. The determination of the attribute transform domain prediction value of the current block based on the comparison result of the occupancy information difference parameter and the preset value, and the inter-frame transform domain prediction value and / or the intra-frame transform domain prediction value, includes: If the comparison result shows that the occupancy information difference parameter is greater than the third value, the attribute transform domain prediction value of the current block is determined based on the inter-frame transform domain prediction value and the intra-frame transform domain prediction value. When the occupancy information difference parameter is less than or equal to the third value, the attribute transform domain prediction value of the current block is determined based on the preset weight parameter, the inter-frame transform domain prediction value, and the intra-frame transform domain prediction value. The method according to claim 6 or 8, wherein Determining the attribute transform domain prediction value of the current block based on the inter-frame transform domain prediction value and the intra-frame transform domain prediction value includes: The mean of the inter-frame transform domain prediction value and the intra-frame transform domain prediction value is determined as the attribute transform domain prediction value of the current block. The method of claim 3, wherein, The step of determining the attribute transform domain prediction value of the current block based on the occupancy information difference parameter, the inter-frame transform domain prediction value, and / or the intra-frame transform domain prediction value includes: Based on the comparison results of the occupancy information difference parameter and the preset value, the first weight corresponding to the inter-frame transform domain prediction value and the second weight corresponding to the intra-frame transform domain prediction value are determined. The attribute transform domain prediction value of the current block is determined based on the first weight, the second weight, the inter-frame transform domain prediction value, and the intra-frame transform domain prediction value. The method of claim 10, wherein, The preset value includes a first value. The step of determining the first weight corresponding to the inter-frame transform domain prediction value and the second weight corresponding to the intra-frame transform domain prediction value based on the comparison result of the occupancy information difference parameter and the preset value includes: If the comparison result shows that the difference parameter of the placeholder information is greater than the first value, the first weight is determined to be 0. The method of claim 10, wherein, The preset value includes a first value and a second value. The step of determining the first weight corresponding to the inter-frame transform domain prediction value and the second weight corresponding to the intra-frame transform domain prediction value based on the comparison result of the occupancy information difference parameter and the preset value includes: If the comparison result is that the difference parameter of the placeholder information is less than or equal to the first value and greater than or equal to the second value, then the first weight and the second weight are determined to be equal. The method of claim 10, wherein, The preset value includes a second value. The step of determining the first weight corresponding to the inter-frame transform domain prediction value and the second weight corresponding to the intra-frame transform domain prediction value based on the comparison result of the occupancy information difference parameter and the preset value includes: If the difference parameter of the occupancy information is less than the second value, the second weight is determined to be 0. The method of claim 10, wherein, The preset value includes a third value. The step of determining the first weight corresponding to the inter-frame transform domain prediction value and the second weight corresponding to the intra-frame transform domain prediction value based on the comparison result of the occupancy information difference parameter and the preset value includes: If the difference parameter of the occupancy information is greater than the third value, the first weight and the second weight are determined to be equal; If the difference parameter of the placeholder information is less than or equal to the third value, the ratio of the second weight to the first weight is determined to be 3. The method according to any one of claims 1-14, wherein, The placeholder information difference parameter is an integer greater than or equal to 0 and less than or equal to 8. The method of any one of claims 1-15, wherein The method further includes: Decode the bitstream and determine the attribute transformation domain residual value corresponding to the current block. The method of claim 16, wherein, The method further includes: The attribute transformation domain value corresponding to the current block is determined based on the attribute transformation domain residual value and the attribute transformation domain prediction value of the current block. The method of any one of claims 1-17, wherein The method further includes: Decode the bitstream to determine the prediction mode identifier information corresponding to the current RAHT layer; The prediction mode corresponding to the current RAHT layer is determined based on the prediction mode identification information. The method of claim 18, wherein, Determining the prediction mode corresponding to the current RAHT layer based on the prediction mode identification information includes: When the prediction mode identifier information takes the fourth value, the prediction mode corresponding to the current RAHT layer is determined according to the number of the current RAHT layer. When the prediction mode identifier information is the fifth value, the prediction mode corresponding to the current RAHT layer is determined to be the inter-frame prediction mode. If the prediction mode identifier information is the sixth value, skip the prediction transformation of the current RAHT layer. The method of claim 19, wherein, Determining the prediction mode corresponding to the current RAHT layer based on the current RAHT layer number includes: If the number of layers in the current RAHT layer is greater than or equal to a first preset value and less than or equal to a second preset value, the prediction mode corresponding to the current RAHT layer is determined to be a hybrid prediction mode. If the number of layers in the current RAHT layer is less than a first preset value or greater than a second preset value, the prediction mode corresponding to the current RAHT layer is determined to be the intra-frame prediction mode. A point cloud encoding method, applied to an encoder, the method comprising: When the hybrid prediction mode is used in the current RAHT layer, determine the inter-frame reference block corresponding to the current block; Based on the occupancy information of the current block and the occupancy information of the inter-frame reference block, determine the occupancy information difference parameter between the current block and the inter-frame reference block; The attribute transformation domain prediction value corresponding to the current block is determined based on the placeholder information difference parameter. The method of claim 21, wherein, The method further includes: Determine the inter-frame transform domain prediction value corresponding to the current block, and / or determine the intra-frame transform domain prediction value corresponding to the current block. The method of claim 22, wherein, The step of determining the attribute transform domain prediction value corresponding to the current block based on the occupancy information difference parameter includes: Based on the occupancy information difference parameter, and the inter-frame transform domain prediction value and / or the intra-frame transform domain prediction value, the attribute transform domain prediction value of the current block is determined. The method of claim 23, wherein, The step of determining the attribute transform domain prediction value of the current block based on the occupancy information difference parameter, the inter-frame transform domain prediction value, and / or the intra-frame transform domain prediction value includes: Based on the comparison results of the occupancy information difference parameters and preset values, as well as the inter-frame transform domain prediction value and / or the intra-frame transform domain prediction value, the attribute transform domain prediction value of the current block is determined. The method of claim 24, wherein, The preset value includes a first value. The determination of the attribute transform domain prediction value of the current block based on the comparison result between the occupancy information difference parameter and the preset value, and the inter-frame transform domain prediction value and / or the intra-frame transform domain prediction value, includes: If the comparison result shows that the placeholder information difference parameter is greater than the first value, the attribute transform domain prediction value of the current block is determined based on the intra-frame transform domain prediction value. The method of claim 24, wherein, The preset value includes a first value and a second value. The determination of the attribute transform domain prediction value of the current block based on the comparison result of the occupancy information difference parameter and the preset value, and the inter-frame transform domain prediction value and / or the intra-frame transform domain prediction value, includes: If the comparison result is that the placeholder information difference parameter is less than or equal to the first value and greater than or equal to the second value, the attribute transform domain prediction value of the current block is determined based on the inter-frame transform domain prediction value and the intra-frame transform domain prediction value. The method of claim 24, wherein, The preset value includes a second value. The determination of the attribute transform domain prediction value of the current block based on the comparison result of the occupancy information difference parameter and the preset value, and the inter-frame transform domain prediction value and / or the intra-frame transform domain prediction value, includes: If the comparison result shows that the occupancy information difference parameter is less than the second value, the attribute transform domain prediction value of the current block is determined based on the inter-frame transform domain prediction value. The method of claim 24, wherein, The preset value includes a third value. The determination of the attribute transform domain prediction value of the current block based on the comparison result of the occupancy information difference parameter and the preset value, and the inter-frame transform domain prediction value and / or the intra-frame transform domain prediction value, includes: If the comparison result shows that the occupancy information difference parameter is greater than the third value, the attribute transform domain prediction value of the current block is determined based on the inter-frame transform domain prediction value and the intra-frame transform domain prediction value. When the occupancy information difference parameter is less than or equal to the third value, the attribute transform domain prediction value of the current block is determined based on the preset weight parameter, the inter-frame transform domain prediction value, and the intra-frame transform domain prediction value. The method of claim 26 or 28, wherein, Determining the attribute transform domain prediction value of the current block based on the inter-frame transform domain prediction value and the intra-frame transform domain prediction value includes: The mean of the inter-frame transform domain prediction value and the intra-frame transform domain prediction value is determined as the attribute transform domain prediction value of the current block. The method of claim 23, wherein, The step of determining the attribute transform domain prediction value of the current block based on the occupancy information difference parameter, the inter-frame transform domain prediction value, and / or the intra-frame transform domain prediction value includes: Based on the comparison results of the occupancy information difference parameter and the preset value, the first weight corresponding to the inter-frame transform domain prediction value and the second weight corresponding to the intra-frame transform domain prediction value are determined. The attribute transform domain prediction value of the current block is determined based on the first weight, the second weight, the inter-frame transform domain prediction value, and the intra-frame transform domain prediction value. The method of claim 30, wherein, The preset value includes a first value. The step of determining the first weight corresponding to the inter-frame transform domain prediction value and the second weight corresponding to the intra-frame transform domain prediction value based on the comparison result of the occupancy information difference parameter and the preset value includes: If the comparison result shows that the difference parameter of the placeholder information is greater than the first value, the first weight is determined to be 0. The method of claim 30, wherein, The preset value includes a first value and a second value. The step of determining the first weight corresponding to the inter-frame transform domain prediction value and the second weight corresponding to the intra-frame transform domain prediction value based on the comparison result of the occupancy information difference parameter and the preset value includes: If the comparison result is that the difference parameter of the placeholder information is less than or equal to the first value and greater than or equal to the second value, then the first weight and the second weight are determined to be equal. The method of claim 30, wherein, The preset value includes a second value. The step of determining the first weight corresponding to the inter-frame transform domain prediction value and the second weight corresponding to the intra-frame transform domain prediction value based on the comparison result of the occupancy information difference parameter and the preset value includes: If the difference parameter of the occupancy information is less than the second value, the second weight is determined to be 0. The method of claim 30, wherein, The preset value includes a third value. The step of determining the first weight corresponding to the inter-frame transform domain prediction value and the second weight corresponding to the intra-frame transform domain prediction value based on the comparison result of the occupancy information difference parameter and the preset value includes: If the difference parameter of the occupancy information is greater than the third value, the first weight and the second weight are determined to be equal; If the difference parameter of the placeholder information is less than or equal to the third value, the ratio of the second weight to the first weight is determined to be 3. The method according to any one of claims 21-34, wherein, The placeholder information difference parameter is an integer greater than or equal to 0 and less than or equal to 8. The method of any one of claims 21-35, wherein The method further includes: The attribute transformation domain residual value corresponding to the current block is determined based on the true value of the attribute transformation domain and the predicted value of the attribute transformation domain of the current block; Write the attribute transformation domain residual value corresponding to the current block into the bitstream. The method of any one of claims 21-36, wherein The method further includes: Determine the prediction mode corresponding to the current RAHT layer; Determine the prediction mode identifier information corresponding to the current RAHT layer based on the prediction mode corresponding to the current RAHT layer; Write the prediction mode identifier information corresponding to the current RAHT layer into the bitstream. The method of claim 37, wherein, Determining the prediction mode corresponding to the current RAHT layer includes: Based on the rate-distortion optimization algorithm, the first generation value corresponding to the inter-frame prediction mode, the second generation value corresponding to the intra-frame prediction mode, the third generation value corresponding to the hybrid prediction mode, and the fourth generation value corresponding to skipping the prediction transformation are determined respectively. The prediction pattern corresponding to the current RAHT layer is determined based on the first-generation value, the second-generation value, the third-generation value, and the fourth-generation value. The method of claim 38, wherein, The step of determining the prediction mode identifier information corresponding to the current RAHT layer based on the prediction mode corresponding to the current RAHT layer includes: When the prediction mode corresponding to the current RAHT layer is an intra-prediction mode or a hybrid prediction mode, the value of the prediction mode identifier information corresponding to the current RAHT layer is determined to be the fourth value. When the prediction mode corresponding to the current RAHT layer is the inter-frame prediction mode, the value of the prediction mode identifier information corresponding to the current RAHT layer is determined to be the fifth value. If the prediction mode corresponding to the current RAHT layer is to skip the prediction transformation, the value of the prediction mode identifier information corresponding to the current RAHT layer is determined to be the sixth value. A bitstream, wherein, The bitstream is generated by bit encoding based on information to be encoded; wherein the information to be encoded includes at least one of the following: Attribute transformation domain residual value, prediction mode identification information. An encoder, the encoder comprising: The first determining unit is configured to determine the inter-frame reference block corresponding to the current block when the hybrid prediction mode is used in the current RAHT layer. Based on the occupancy information of the current block and the occupancy information of the inter-frame reference block, determine the occupancy information difference parameter between the current block and the inter-frame reference block; The attribute transformation domain prediction value corresponding to the current block is determined based on the placeholder information difference parameter. An encoder, the encoder comprising a first memory and a first processor; wherein, The first memory is used to store computer programs that can run on the first processor; The first processor is configured to, when running the computer program, perform the method as described in any one of claims 21-39. A decoder, the decoder comprising: The second determining unit is configured to determine the inter-frame reference block corresponding to the current block when the hybrid prediction mode is used in the current RAHT layer. Based on the occupancy information of the current block and the occupancy information of the inter-frame reference block, determine the occupancy information difference parameter between the current block and the inter-frame reference block; The attribute transformation domain prediction value corresponding to the current block is determined based on the placeholder information difference parameter. A decoder, the decoder comprising a second memory and a second processor; wherein, The second memory is used to store computer programs that can run on the second processor; The second processor is configured to, when running the computer program, perform the method as described in any one of claims 1-20. A computer-readable storage medium for storing a bitstream generated by the encoding method of any one of claims 21-39.

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