Three-dimensional data generation method, three-dimensional data processing method, three-dimensional data generation device, and three-dimensional data processing device

Abstract

To reduce the amount of processing.SOLUTION: A three-dimensional data generation method generates a bit stream including multiple pieces of encoded data obtained by encoding data corresponding to each of different three-dimensional spaces (S4932). The bit stream includes a first identifier indicating a space corresponding to each of the multiple pieces of encoded data, and a second identifier indicating data corresponding to each of the multiple pieces of encoded data. For example, each of the multiple pieces of encoded data includes encoded data of position information and encoded data of attribute information. The first identifier and the second identifier may be stored in control information of the encoded data of the position information.SELECTED DRAWING: Figure 59

Description

[Technical Field]

[0001] The present disclosure relates to a three-dimensional data encoding method, a three-dimensional data decoding method, a three-dimensional data encoding device, and a three-dimensional data decoding device. [Background technology]

[0002] In the future, devices and services that utilize 3D data are expected to become widespread in a wide range of fields, including computer vision for autonomous operation of automobiles or robots, map information, surveillance, infrastructure inspection, video distribution, etc. 3D data can be acquired in a variety of ways, including distance sensors such as range finders, stereo cameras, or a combination of multiple monocular cameras.

[0003] One method of representing three-dimensional data is a point cloud, which represents the shape of a three-dimensional structure using a group of points in three-dimensional space. A point cloud stores the position and color of the points. Point clouds are expected to become the mainstream method of representing three-dimensional data, but point clouds require a very large amount of data. Therefore, when storing or transmitting three-dimensional data, data compression through encoding is essential, just as with two-dimensional video images (examples include MPEG-4 AVC or HEVC standardized by MPEG).

[0004] In addition, compression of point clouds is partially supported by public libraries that perform point cloud-related processing (Point Cloud Library).

[0005] Furthermore, a technique is known in which three-dimensional map data is used to search for and display facilities located around a vehicle (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] International Publication No. 2014 / 020663 Summary of the Invention [Problem to be solved by the invention]

[0007] In the encoding and decoding of three-dimensional data, it is desirable to reduce the amount of processing in a three-dimensional data decoding device.

[0008] An object of the present disclosure is to provide a three-dimensional data encoding method, a three-dimensional data decoding method, a three-dimensional data encoding device, or a three-dimensional data decoding device that can reduce the amount of processing in the three-dimensional data decoding device. [Means for solving the problem]

[0009] A three-dimensional data generation method according to one aspect of the present disclosure includes: and a plurality of pieces of control information for each of the plurality of pieces of encoded data. generating a bitstream containing Each of the plurality of pieces of control information includes a Encoding Data Ta a first identifier indicating the corresponding space; corresponding to the control information Encoding Data Ta a second identifier indicating the corresponding data; is stored .

[0010] A three-dimensional data processing method according to one aspect of the present disclosure includes: extracting from a bitstream a plurality of encoded data pieces in which data corresponding to different three-dimensional spaces are encoded; and a plurality of pieces of control information for each of the plurality of pieces of encoded data. Get The control information corresponding to the control information stored in the plurality of pieces of control information Encoding Data Ta a first identifier indicating the corresponding space; corresponding to the control information Encoding Data Ta A second identifier indicating the corresponding data is obtained. [Effects of the Invention]

[0011] The present disclosure can provide a three-dimensional data encoding method, a three-dimensional data decoding method, a three-dimensional data encoding device, or a three-dimensional data decoding device that can reduce the amount of processing in the three-dimensional data decoding device. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a diagram showing a configuration of a three-dimensional data encoding / decoding system according to the first embodiment. [Figure 2] FIG. 2 is a diagram illustrating an example of the configuration of point cloud data according to the first embodiment. [Figure 3] FIG. 3 is a diagram showing an example of the structure of a data file in which point cloud data information according to the first embodiment is described. [Figure 4] FIG. 4 is a diagram showing types of point cloud data according to the first embodiment. [Figure 5] FIG. 5 is a diagram showing a configuration of a first encoding unit according to the first embodiment. [Figure 6] FIG. 6 is a block diagram of a first encoding unit according to the first embodiment. [Figure 7] FIG. 7 is a diagram illustrating a configuration of a first decoding unit according to the first embodiment. [Figure 8] FIG. 8 is a block diagram of a first decoding unit according to the first embodiment. [Figure 9] FIG. 9 is a diagram showing a configuration of a second encoding unit according to the first embodiment. [Figure 10] FIG. 10 is a block diagram of a second encoding unit according to the first embodiment. [Figure 11] FIG. 11 is a diagram illustrating a configuration of a second decoding unit according to the first embodiment. [Figure 12] FIG. 12 is a block diagram of a second decoding unit according to the first embodiment. [Figure 13] FIG. 13 is a diagram showing a protocol stack related to PCC encoded data according to the first embodiment. [Figure 14] FIG. 14 is a block diagram of the encoding unit according to the first embodiment. [Figure 15] FIG. 15 is a block diagram of a decoding unit according to the first embodiment. [Figure 16] FIG. 16 is a flowchart of the encoding process according to the first embodiment. [Figure 17] FIG. 17 is a flowchart of the decoding process according to the first embodiment. [Figure 18] FIG. 18 is a diagram illustrating a basic structure of the ISOBMFF according to the second embodiment. [Figure 19] FIG. 19 is a diagram illustrating a protocol stack according to the second embodiment. [Figure 20] FIG. 20 is a diagram showing an example in which NAL units according to the second embodiment are stored in a file for codec 1. In FIG. [Figure 21] FIG. 21 is a diagram showing an example in which NAL units according to the second embodiment are stored in a file for codec 2. In FIG. [Figure 22] FIG. 22 is a diagram illustrating a configuration of a first multiplexing unit according to the second embodiment. [Figure 23] FIG. 23 is a diagram illustrating a configuration of a first demultiplexing unit according to the second embodiment. [Figure 24] FIG. 24 is a diagram illustrating a configuration of a second multiplexing unit according to the second embodiment. [Figure 25] FIG. 25 is a diagram illustrating a configuration of a second demultiplexing unit according to the second embodiment. [Figure 26] FIG. 26 is a flowchart of a process performed by the first multiplexing unit according to the second embodiment. [Figure 27] FIG. 27 is a flowchart of a process performed by the second multiplexing unit according to the second embodiment. [Figure 28] FIG. 28 is a flowchart of processing by the first demultiplexing unit and the first decoding unit according to the second embodiment. [Figure 29] FIG. 29 is a flowchart of processing by the second demultiplexing unit and the second decoding unit according to the second embodiment. [Figure 30] FIG. 30 is a diagram illustrating a configuration of an encoding unit and a third multiplexing unit according to the third embodiment. [Figure 31] FIG. 31 is a diagram illustrating a configuration of a third demultiplexing unit and a decoding unit according to the third embodiment. [Figure 32] FIG. 32 is a flowchart of a process performed by the third multiplexing unit according to the third embodiment. [Figure 33]FIG. 33 is a flowchart of processing by a third demultiplexing unit and a decoding unit according to the third embodiment. [Figure 34] FIG. 34 is a flowchart of processing by the three-dimensional data storage device according to the third embodiment. [Figure 35] FIG. 35 is a flowchart of the processing performed by the three-dimensional data acquisition device according to the third embodiment. [Figure 36] FIG. 36 is a diagram illustrating the configurations of an encoding unit and a multiplexing unit according to the fourth embodiment. [Figure 37] FIG. 37 is a diagram illustrating an example of a structure of coded data according to the fourth embodiment. [Figure 38] FIG. 38 is a diagram showing an example of the structure of coded data and NAL units according to the fourth embodiment. [Figure 39] FIG. 39 is a diagram illustrating an example of the semantics of pcc_nal_unit_type according to the fourth embodiment. [Figure 40] FIG. 40 is a diagram showing an example of the transmission order of NAL units according to the fourth embodiment. [Figure 41] FIG. 41 is a flowchart of processing by the three-dimensional data encoding device according to the fourth embodiment. [Figure 42] FIG. 42 is a flowchart of processing by the three-dimensional data decoding device according to the fourth embodiment. [Figure 43] FIG. 43 is a flowchart of the multiplexing process according to the fourth embodiment. [Figure 44] FIG. 44 is a flowchart of the demultiplexing process according to the fourth embodiment. [Figure 45] FIG. 45 is a flowchart of processing by the three-dimensional data encoding device according to the fourth embodiment. [Figure 46] FIG. 46 is a flowchart of processing by the three-dimensional data decoding device according to the fourth embodiment. [Figure 47] FIG. 47 is a block diagram of a first encoding unit according to the fifth embodiment. [Figure 48] FIG. 48 is a block diagram of a first decoding unit according to the fifth embodiment. [Figure 49] FIG. 49 is a block diagram of a division unit according to the fifth embodiment. [Figure 50] FIG. 50 is a diagram showing an example of division into slices and tiles according to the fifth embodiment. [Figure 51] FIG. 51 is a diagram showing an example of a division pattern of slices and tiles according to the fifth embodiment. [Figure 52] FIG. 52 is a diagram illustrating an example of a dependency relationship according to the fifth embodiment. [Figure 53] FIG. 53 is a diagram showing an example of the decoding order of data according to the fifth embodiment. [Figure 54] FIG. 54 is a flowchart of the encoding process according to the fifth embodiment. [Figure 55] FIG. 55 is a block diagram of a combining unit according to the fifth embodiment. [Figure 56] FIG. 56 is a diagram showing an example of the structure of coded data and NAL units according to the fifth embodiment. [Figure 57] FIG. 57 is a flowchart of the encoding process according to the fifth embodiment. [Figure 58] FIG. 58 is a flowchart of the decoding process according to the fifth embodiment. [Figure 59] FIG. 59 is a flowchart of the encoding process according to the fifth embodiment. [Figure 60] FIG. 60 is a flowchart of the decoding process according to the fifth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0013] A three-dimensional data encoding method according to one embodiment of the present disclosure generates a plurality of coded data corresponding to each of the plurality of coded data, by encoding each of the plurality of divided data, each of which contains one or more three-dimensional points, contained in a plurality of subspaces obtained by dividing a target space containing a plurality of three-dimensional points, and generates a bit stream including the plurality of coded data and a plurality of control information for each of the plurality of coded data, wherein each of the plurality of control information stores a first identifier indicating the subspace corresponding to the coded data corresponding to the control information, and a second identifier indicating the divided data corresponding to the coded data corresponding to the control information.

[0014] According to this, a three-dimensional data decoding device that decodes a bitstream generated by the three-dimensional data encoding method can easily restore the target space by combining data from multiple divided data sets using the first identifier and the second identifier, thereby reducing the amount of processing in the three-dimensional data decoding device.

[0015] For example, the encoding may encode position information and attribute information of three-dimensional points contained in each of the plurality of split data, each of the plurality of encoded data including encoded data of the position information and encoded data of the attribute information, each of the plurality of control information including control information of the encoded data of the position information and control information of the encoded data of the attribute information, and the first identifier and the second identifier may be stored in the control information of the encoded data of the position information.

[0016] For example, in the bitstream, each of the plurality of pieces of control information may be placed before the coded data corresponding to that control information.

[0017] A three-dimensional data decoding method according to one embodiment of the present disclosure obtains, from a bitstream containing a plurality of encoded data pieces generated by encoding each of a plurality of split data pieces containing one or more three-dimensional points, each of which is contained in a plurality of subspaces into which a target space containing a plurality of three-dimensional points is divided, and a plurality of control information pieces for each of the plurality of encoded data pieces, a first identifier indicating the subspace corresponding to the encoded data piece corresponding to the control information, and a second identifier indicating the split data piece corresponding to the encoded data piece corresponding to the control information, which are stored in the plurality of control information pieces; restores the plurality of split data pieces by decoding the plurality of encoded data pieces; and restores the target space by combining the plurality of split data pieces using the first identifier and the second identifier.

[0018] According to this, the three-dimensional data decoding method can easily restore the target space by combining the data of the plurality of divided data using the first identifier and the second identifier, thereby reducing the amount of processing in the three-dimensional data decoding device.

[0019] For example, each of the plurality of encoded data may be generated by encoding position information and attribute information of a three-dimensional point included in the corresponding split data, and may include encoded data for the position information and encoded data for the attribute information, each of the plurality of control information may include control information for the encoded data for the position information and control information for the encoded data for the attribute information, and the first identifier and the second identifier may be stored in the control information for the encoded data for the position information.

[0020] For example, in the bitstream, the control information may be placed before the corresponding coded data.

[0021] In addition, a three-dimensional data encoding device according to one aspect of the present disclosure includes a processor and a memory, and the processor uses the memory to encode each of a plurality of divided data pieces, each of which includes one or more three-dimensional points and is included in a plurality of subspaces into which a target space containing a plurality of three-dimensional points is divided, thereby generating a plurality of coded data pieces corresponding to each of the plurality of divided data pieces, and generating a bit stream including the plurality of coded data pieces and a plurality of control information pieces for each of the plurality of coded data pieces, and each of the plurality of control information pieces stores a first identifier indicating the subspace corresponding to the coded data piece corresponding to the control information, and a second identifier indicating the divided data piece corresponding to the coded data piece corresponding to the control information.

[0022] This allows a three-dimensional data decoding device that decodes a bitstream generated by the three-dimensional data encoding device to easily restore the target space by combining data from the plurality of divided data using the first identifier and the second identifier, thereby reducing the amount of processing required in the three-dimensional data decoding device.

[0023] In addition, a three-dimensional data decoding device according to one aspect of the present disclosure includes a processor and a memory, and the processor uses the memory to obtain, from a bitstream including a plurality of coded data pieces generated by encoding each of a plurality of split data pieces, each of which contains one or more three-dimensional points and is included in a plurality of subspaces divided from a target space containing a plurality of three-dimensional points, and a plurality of control information pieces for each of the plurality of coded data pieces, a first identifier indicating the subspace corresponding to the coded data piece corresponding to the control information and a second identifier indicating the split data piece corresponding to the coded data piece corresponding to the control information, which are stored in the plurality of control information pieces, and the plurality of coded data pieces are decoded to restore the plurality of split data pieces, and the target space is restored by combining the plurality of split data pieces using the first identifier and the second identifier.

[0024] This allows the three-dimensional data decoding device to easily restore the target space by combining the data of the plurality of divided data using the first identifier and the second identifier, thereby reducing the amount of processing in the three-dimensional data decoding device.

[0025] These comprehensive or specific aspects may be realized as a system, a method, an integrated circuit, a computer program, or a computer-readable recording medium such as a CD-ROM, or may be realized as any combination of a system, a method, an integrated circuit, a computer program, and a recording medium.

[0026] Hereinafter, the embodiments will be described in detail with reference to the drawings. Note that each of the embodiments described below represents a specific example of the present disclosure. The numerical values, shapes, materials, components, component placement and connection configurations, steps, and step order shown in the following embodiments are merely examples and are not intended to limit the present disclosure. Furthermore, among the components in the following embodiments, components that are not described in an independent claim that represents a superordinate concept will be described as optional components.

[0027] (Embodiment 1) When using encoded point cloud data in an actual device or service, it is desirable to transmit and receive the information required for the application in order to reduce network bandwidth. However, until now, such a function has not existed in the encoding structure of 3D data, and no encoding method for this purpose has existed.

[0028] In this embodiment, we will describe a three-dimensional data encoding method and a three-dimensional data encoding device that provide the function of transmitting and receiving information required for the purpose in encoded data of a three-dimensional point cloud, as well as a three-dimensional data decoding method and a three-dimensional data decoding device that decodes the encoded data, a three-dimensional data multiplexing method that multiplexes the encoded data, and a three-dimensional data transmission method that transmits the encoded data.

[0029] In particular, two encoding methods (encoding schemes) are currently being considered as encoding methods (encoding systems) for point cloud data; however, the structure of the encoded data and the method for storing the encoded data in a system format have not been defined, and as things stand, there is a problem that MUX processing (multiplexing) in the encoding unit, or transmission or storage, is not possible.

[0030] Furthermore, there has been no method to date that supports a format in which two codecs, a first encoding method and a second encoding method, are mixed, such as PCC (Point Cloud Compression).

[0031] In this embodiment, a description will be given of the structure of PCC encoded data in which two codecs, a first encoding method and a second encoding method, are mixed, and a method of storing the encoded data in a system format.

[0032] First, the configuration of a three-dimensional data (point cloud data) encoding / decoding system according to this embodiment will be described. Fig. 1 is a diagram showing an example of the configuration of a three-dimensional data encoding / decoding system according to this embodiment. As shown in Fig. 1, the three-dimensional data encoding / decoding system includes a three-dimensional data encoding system 4601, a three-dimensional data decoding system 4602, a sensor terminal 4603, and an external connection unit 4604.

[0033] The three-dimensional data encoding system 4601 generates encoded data or multiplexed data by encoding point cloud data, which is three-dimensional data. Note that the three-dimensional data encoding system 4601 may be a three-dimensional data encoding device realized by a single device, or may be a system realized by multiple devices. Furthermore, the three-dimensional data encoding device may include some of the multiple processing units included in the three-dimensional data encoding system 4601.

[0034] The three-dimensional data encoding system 4601 includes a point cloud data generation system 4611, a presentation unit 4612, an encoding unit 4613, a multiplexing unit 4614, an input / output unit 4615, and a control unit 4616. The point cloud data generation system 4611 includes a sensor information acquisition unit 4617 and a point cloud data generation unit 4618.

[0035] The sensor information acquisition unit 4617 acquires sensor information from the sensor terminal 4603 and outputs the sensor information to the point cloud data generation unit 4618. The point cloud data generation unit 4618 generates point cloud data from the sensor information and outputs the point cloud data to the encoding unit 4613.

[0036] The presentation unit 4612 presents the sensor information or point cloud data to the user. For example, the presentation unit 4612 displays information or an image based on the sensor information or point cloud data.

[0037] The encoding unit 4613 encodes (compresses) the point cloud data, and outputs the obtained encoded data, control information obtained in the encoding process, and other additional information to the multiplexing unit 4614. The additional information includes, for example, sensor information.

[0038] The multiplexing unit 4614 generates multiplexed data by multiplexing the coded data input from the coding unit 4613, the control information, and the additional information. The format of the multiplexed data is, for example, a file format for storage or a packet format for transmission.

[0039] The input / output unit 4615 (e.g., a communication unit or an interface) outputs the multiplexed data to the outside. Alternatively, the multiplexed data is stored in a storage unit such as an internal memory. The control unit 4616 (or application execution unit) controls each processing unit. In other words, the control unit 4616 controls encoding, multiplexing, etc.

[0040] The sensor information may be input to the encoding unit 4613 or the multiplexing unit 4614. The input / output unit 4615 may output the point cloud data or the encoded data directly to the outside.

[0041] The transmission signal (multiplexed data) output from the three-dimensional data encoding system 4601 is input to the three-dimensional data decoding system 4602 via the external connection unit 4604 .

[0042] The three-dimensional data decoding system 4602 generates point cloud data, which is three-dimensional data, by decoding the encoded data or multiplexed data. Note that the three-dimensional data decoding system 4602 may be a three-dimensional data decoding device realized by a single device, or may be a system realized by multiple devices. Furthermore, the three-dimensional data decoding device may include some of the multiple processing units included in the three-dimensional data decoding system 4602.

[0043] The three-dimensional data decoding system 4602 includes a sensor information acquisition unit 4621 , an input / output unit 4622 , a demultiplexing unit 4623 , a decoding unit 4624 , a presentation unit 4625 , a user interface 4626 , and a control unit 4627 .

[0044] The sensor information acquisition unit 4621 acquires sensor information from the sensor terminal 4603 .

[0045] The input / output unit 4622 acquires the transmission signal, decodes the multiplexed data (file format or packets) from the transmission signal, and outputs the multiplexed data to the demultiplexer 4623.

[0046] The demultiplexer 4623 obtains the coded data, control information, and additional information from the multiplexed data, and outputs the coded data, control information, and additional information to the decoder 4624.

[0047] The decoding unit 4624 reconstructs the point cloud data by decoding the encoded data.

[0048] The presentation unit 4625 presents the point cloud data to the user. For example, the presentation unit 4625 displays information or images based on the point cloud data. The user interface 4626 acquires instructions based on user operations. The control unit 4627 (or the application execution unit) controls each processing unit. In other words, the control unit 4627 controls demultiplexing, decoding, presentation, etc.

[0049] The input / output unit 4622 may acquire point cloud data or encoded data directly from the outside. The presentation unit 4625 may acquire additional information such as sensor information and present information based on the additional information. The presentation unit 4625 may perform presentation based on a user instruction acquired by the user interface 4626.

[0050] The sensor terminal 4603 generates sensor information, which is information obtained by a sensor. The sensor terminal 4603 is a terminal equipped with a sensor or a camera, and examples thereof include a moving body such as an automobile, a flying object such as an airplane, a mobile terminal, or a camera.

[0051] The sensor information that can be acquired by the sensor terminal 4603 includes, for example, (1) the distance between the sensor terminal 4603 and an object, or the reflectance of the object, obtained from a LIDAR, millimeter-wave radar, or infrared sensor, and (2) the distance between a camera and an object, or the reflectance of the object, obtained from multiple monocular camera images or stereo camera images. The sensor information may also include the attitude, direction, gyro (angular velocity), position (GPS information or altitude), speed, acceleration, etc. of the sensor. The sensor information may also include temperature, air pressure, humidity, magnetism, etc.

[0052] The external connection unit 4604 is realized by an integrated circuit (LSI or IC), an external storage unit, communication with a cloud server via the Internet, broadcasting, or the like.

[0053] Next, point cloud data will be described. Fig. 2 is a diagram showing the configuration of point cloud data. Fig. 3 is a diagram showing an example of the configuration of a data file in which information about point cloud data is written.

[0054] Point cloud data includes data on multiple points. The data on each point includes location information (three-dimensional coordinates) and attribute information for that location information. A collection of multiple points is called a point cloud. For example, a point cloud can represent the three-dimensional shape of an object.

[0055] Position information such as three-dimensional coordinates is sometimes called geometry. Data for each point may also include attribute information of multiple attribute types. Attribute types include, for example, color or reflectance.

[0056] One piece of attribute information may be associated with one piece of location information, or multiple pieces of attribute information with different attribute types may be associated with one piece of location information, or multiple pieces of attribute information of the same attribute type may be associated with one piece of location information.

[0057] The configuration example of the data file shown in FIG. 3 is an example in which there is a one-to-one correspondence between position information and attribute information, and shows the position information and attribute information of N points that make up the point cloud data.

[0058] The position information is, for example, information on the three axes x, y, and z. The attribute information is, for example, RGB color information. A typical data file is a ply file.

[0059] Next, the types of point cloud data will be explained. Fig. 4 is a diagram showing the types of point cloud data. As shown in Fig. 4, point cloud data includes static objects and dynamic objects.

[0060] A static object is 3D point cloud data at any time (a certain time). A dynamic object is 3D point cloud data that changes over time. Hereinafter, 3D point cloud data at a certain time will be referred to as a PCC frame, or simply a frame.

[0061] The object may be a point cloud with a certain area restriction, such as ordinary video data, or a large-scale point cloud with no area restriction, such as map information.

[0062] Furthermore, there may be point cloud data of various densities, such as sparse point cloud data and dense point cloud data.

[0063] Each processing unit will be described in detail below. Sensor information is acquired by various methods, such as a distance sensor such as a LIDAR or a range finder, a stereo camera, or a combination of multiple monocular cameras. The point cloud data generation unit 4618 generates point cloud data based on the sensor information acquired by the sensor information acquisition unit 4617. The point cloud data generation unit 4618 generates position information as point cloud data, and adds attribute information for the position information to the position information.

[0064] The point cloud data generation unit 4618 may process the point cloud data when generating position information or adding attribute information. For example, the point cloud data generation unit 4618 may reduce the amount of data by deleting point clouds with overlapping positions. In addition, the point cloud data generation unit 4618 may convert (position shift, rotation, normalization, etc.) the position information or render the attribute information.

[0065] In FIG. 1, the point cloud data generation system 4611 is included in the three-dimensional data encoding system 4601, but it may be provided independently outside the three-dimensional data encoding system 4601.

[0066] The encoding unit 4613 generates encoded data by encoding the point cloud data based on a predetermined encoding method. There are two main types of encoding methods: the first is an encoding method that uses position information, and this encoding method will be referred to as the first encoding method hereinafter; and the second is an encoding method that uses a video codec, and this encoding method will be referred to as the second encoding method hereinafter.

[0067] The decoding unit 4624 decodes the coded data based on a predetermined coding method to decode the point group data.

[0068] The multiplexing unit 4614 generates multiplexed data by multiplexing the encoded data using an existing multiplexing method. The generated multiplexed data is transmitted or stored. In addition to the PCC encoded data, the multiplexing unit 4614 multiplexes other media such as video, audio, subtitles, applications, and files, or reference time information. The multiplexing unit 4614 may also multiplex attribute information related to sensor information or point cloud data.

[0069] Multiplexing methods or file formats include ISOBMFF, MPEG-DASH, which is an ISOBMFF-based transmission method, MMT, MPEG-2 TS Systems, and RMP.

[0070] The demultiplexer 4623 extracts PCC encoded data, other media, time information, and the like from the multiplexed data.

[0071] The input / output unit 4615 transmits the multiplexed data using a method suited to the transmission medium or storage medium, such as broadcasting or communication. The input / output unit 4615 may communicate with other devices via the Internet, or may communicate with a storage unit such as a cloud server.

[0072] The communication protocol used may be http, ftp, TCP, UDP, etc. A PULL type communication method or a PUSH type communication method may be used.

[0073] Either wired or wireless transmission may be used. For wired transmission, Ethernet (registered trademark), USB, RS-232C, HDMI (registered trademark), coaxial cable, etc. are used. For wireless transmission, wireless LAN, Wi-Fi (registered trademark), Bluetooth (registered trademark), millimeter waves, etc. are used.

[0074] As a broadcasting system, for example, DVB-T2, DVB-S2, DVB-C2, ATSC3.0, or ISDB-S3 is used.

[0075] Fig. 5 is a diagram showing the configuration of a first encoding unit 4630, which is an example of the encoding unit 4613 that performs encoding using the first encoding method. Fig. 6 is a block diagram of the first encoding unit 4630. The first encoding unit 4630 generates encoded data (encoded stream) by encoding point cloud data using the first encoding method. This first encoding unit 4630 includes a position information encoding unit 4631, an attribute information encoding unit 4632, an additional information encoding unit 4633, and a multiplexing unit 4634.

[0076] The first encoding unit 4630 is characterized in that it performs encoding taking into consideration a three-dimensional structure. The first encoding unit 4630 is also characterized in that the attribute information encoding unit 4632 performs encoding using information obtained from the position information encoding unit 4631. The first encoding method is also called GPCC (Geometry based PCC).

[0077] The point cloud data is PCC point cloud data such as a PLY file, or PCC point cloud data generated from sensor information, and includes position information (Position), attribute information (Attribute), and other additional information (MetaData). The position information is input to a position information encoder 4631, the attribute information is input to an attribute information encoder 4632, and the additional information is input to an additional information encoder 4633.

[0078] The position information encoding unit 4631 encodes the position information to generate encoded position information (Compressed Geometry), which is encoded data. For example, the position information encoding unit 4631 encodes the position information using an N-ary tree structure such as an octree. Specifically, in an octree, the target space is divided into eight nodes (subspaces), and 8-bit information (occupancy code) indicating whether or not a point cloud is included in each node is generated. Furthermore, the node including the point cloud is further divided into eight nodes, and 8-bit information indicating whether or not a point cloud is included in each of the eight nodes is generated. This process is repeated until the number of point clouds included in a predetermined layer or node falls below a threshold.

[0079] The attribute information encoding unit 4632 generates encoded attribute information (Compressed Attribute) that is encoded data by encoding using the configuration information generated by the position information encoding unit 4631. For example, the attribute information encoding unit 4632 determines a reference point (reference node) to be referenced when encoding a target point (target node) to be processed, based on the octree structure generated by the position information encoding unit 4631. For example, the attribute information encoding unit 4632 references a peripheral node or adjacent node whose parent node in the octree is the same as that of the target node. Note that the method of determining the reference relationship is not limited to this.

[0080] Furthermore, the encoding process of the attribute information may include at least one of a quantization process, a prediction process, and an arithmetic coding process. In this case, the reference means using a reference node to calculate a predicted value of the attribute information, or using the state of the reference node (e.g., occupancy information indicating whether the reference node includes a point group) to determine an encoding parameter. For example, the encoding parameter is a quantization parameter in a quantization process, or a context in an arithmetic coding process.

[0081] The additional information encoding unit 4633 generates encoded additional information (Compressed MetaData) that is encoded data by encoding compressible data from the additional information.

[0082] The multiplexing unit 4634 multiplexes the encoding position information, the encoding attribute information, the encoding additional information, and other additional information to generate a compressed stream, which is encoded data. The generated compressed stream is output to a processing unit in a system layer (not shown).

[0083] Next, a first decoding unit 4640, which is an example of the decoding unit 4624 that performs decoding using the first encoding method, will be described. FIG. 7 is a diagram showing the configuration of the first decoding unit 4640. FIG. 8 is a block diagram of the first decoding unit 4640. The first decoding unit 4640 generates point cloud data by decoding, using the first encoding method, coded data (coded stream) coded using the first coding method. The first decoding unit 4640 includes a demultiplexing unit 4641, a position information decoding unit 4642, an attribute information decoding unit 4643, and an additional information decoding unit 4644.

[0084] A coded stream (compressed stream) that is coded data is input to the first decoding unit 4640 from a processing unit in a system layer (not shown).

[0085] The demultiplexer 4641 separates the encoded position information (Compressed Geometry), the encoded attribute information (Compressed Attribute), the encoded additional information (Compressed MetaData), and other additional information from the encoded data.

[0086] The position information decoding unit 4642 generates position information by decoding the encoded position information. For example, the position information decoding unit 4642 restores the position information of a point group represented by three-dimensional coordinates from the encoded position information represented by an N-ary tree structure such as an octree.

[0087] The attribute information decoding unit 4643 decodes the encoded attribute information based on the configuration information generated by the position information decoding unit 4642. For example, the attribute information decoding unit 4643 determines a reference point (reference node) to be referenced in decoding the target point (target node) to be processed based on the octree structure obtained by the position information decoding unit 4642. For example, the attribute information decoding unit 4643 references a peripheral node or adjacent node whose parent node in the octree is the same as that of the target node. Note that the method of determining the reference relationship is not limited to this.

[0088] Furthermore, the attribute information decoding process may include at least one of an inverse quantization process, a prediction process, and an arithmetic decoding process. In this case, the reference means using a reference node to calculate a predicted value of the attribute information, or using the state of the reference node (e.g., occupancy information indicating whether the reference node includes a point group) to determine a decoding parameter. For example, the decoding parameter is a quantization parameter in an inverse quantization process, or a context in an arithmetic decoding process.

[0089] The additional information decoding unit 4644 generates additional information by decoding the encoded additional information. The first decoding unit 4640 uses the additional information necessary for decoding the position information and attribute information during decoding, and outputs the additional information necessary for the application to the outside.

[0090] Next, a description will be given of second encoding unit 4650, which is an example of encoding unit 4613 that performs encoding using the second encoding method. Fig. 9 is a diagram showing the configuration of second encoding unit 4650. Fig. 10 is a block diagram of second encoding unit 4650.

[0091] The second encoding unit 4650 generates encoded data (encoded stream) by encoding the point cloud data using a second encoding method. The second encoding unit 4650 includes an additional information generation unit 4651, a position image generation unit 4652, an attribute image generation unit 4653, a video encoding unit 4654, an additional information encoding unit 4655, and a multiplexing unit 4656.

[0092] The second encoding unit 4650 has a feature of generating a position image and an attribute image by projecting a three-dimensional structure onto a two-dimensional image, and encoding the generated position image and attribute image using an existing video encoding method. The second encoding method is also called VPCC (Video based PCC).

[0093] The point cloud data is PCC point cloud data such as a PLY file, or PCC point cloud data generated from sensor information, and includes position information (Position), attribute information (Attribute), and other additional information (MetaData).

[0094] The additional information generating unit 4651 generates map information of a plurality of two-dimensional images by projecting a three-dimensional structure onto the two-dimensional images.

[0095] The position image generation unit 4652 generates a position image (Geometry Image) based on the position information and the map information generated by the additional information generation unit 4651. This position image is, for example, a distance image in which distance (Depth) is indicated as a pixel value. Note that this distance image may be an image in which multiple point clouds are viewed from a single viewpoint (an image in which multiple point clouds are projected onto a single two-dimensional plane), or may be multiple images in which multiple point clouds are viewed from multiple viewpoints, or may be a single image in which these multiple images are integrated.

[0096] The attribute image generation unit 4653 generates an attribute image based on the attribute information and the map information generated by the additional information generation unit 4651. This attribute image is, for example, an image in which attribute information (for example, color (RGB)) is represented as pixel values. Note that this image may be an image in which multiple point clouds are viewed from one viewpoint (an image in which multiple point clouds are projected onto one two-dimensional plane), or multiple images in which multiple point clouds are viewed from multiple viewpoints, or a single image in which these multiple images are integrated.

[0097] The video encoding unit 4654 generates an encoded position image (Compressed Geometry Image) and an encoded attribute image (Compressed Attribute Image), which are encoded data, by encoding the position image and the attribute image using a video encoding method. Note that any known encoding method may be used as the video encoding method. For example, the video encoding method is AVC, HEVC, or the like.

[0098] The additional information encoding unit 4655 generates encoded additional information (Compressed MetaData) by encoding the additional information, map information, and the like included in the point cloud data.

[0099] The multiplexing unit 4656 multiplexes the encoding position image, the encoding attribute image, the encoding additional information, and other additional information to generate an encoded stream (Compressed Stream) that is encoded data. The generated encoded stream is output to a processing unit in a system layer (not shown).

[0100] Next, a second decoding unit 4660, which is an example of the decoding unit 4624 that performs decoding using the second encoding method, will be described. FIG. 11 is a diagram showing the configuration of the second decoding unit 4660. FIG. 12 is a block diagram of the second decoding unit 4660. The second decoding unit 4660 generates point cloud data by decoding, using the second encoding method, coded data (coded stream) coded using the second coding method. The second decoding unit 4660 includes a demultiplexing unit 4661, a video decoding unit 4662, an additional information decoding unit 4663, a position information generation unit 4664, and an attribute information generation unit 4665.

[0101] A coded stream (compressed stream) that is coded data is input to the second decoding unit 4660 from a processing unit in a system layer (not shown).

[0102] The demultiplexer 4661 separates the encoded position image (Compressed Geometry Image), the encoded attribute image (Compressed Attribute Image), the encoded additional information (Compressed MetaData), and other additional information from the encoded data.

[0103] The video decoding unit 4662 generates a position image and an attribute image by decoding the encoded position image and the encoded attribute image using a video encoding method. Note that any known encoding method may be used as the video encoding method. For example, the video encoding method is AVC or HEVC.

[0104] The additional information decoding unit 4663 decodes the encoded additional information to generate additional information including map information and the like.

[0105] The position information generating unit 4664 generates position information using the position image and map information. The attribute information generating unit 4665 generates attribute information using the attribute image and map information.

[0106] The second decoding unit 4660 uses the additional information necessary for decoding during decoding, and outputs the additional information necessary for the application to the outside.

[0107] The following describes the problems with the PCC encoding method. Fig. 13 is a diagram showing a protocol stack related to PCC encoded data. Fig. 13 shows an example in which other media data such as video (e.g., HEVC) or audio is multiplexed onto the PCC encoded data and transmitted or stored.

[0108] Multiplexing methods and file formats have the function of multiplexing various coded data and transmitting or storing them. To transmit or store coded data, the coded data must be converted into the format of the multiplexing method. For example, HEVC specifies a technology that stores coded data in a data structure called a NAL unit and stores the NAL unit in ISOBMFF.

[0109] On the other hand, currently, a first encoding method (Codec1) and a second encoding method (Codec2) are being considered as methods for encoding point cloud data, but the structure of the encoded data and the method for storing the encoded data in a system format have not been defined, which poses the problem that, as it stands, it is not possible to perform MUX processing (multiplexing) in the encoding unit, transmission, or storage.

[0110] In the following description, unless a specific encoding method is specified, it refers to either the first encoding method or the second encoding method.

[0111] A method for defining NAL units according to this embodiment will be described below. For example, in conventional codecs such as HEVC, one format of NAL units is defined for one codec. However, there has been no method so far to support a format in which two codecs, a first encoding method and a second encoding method (hereinafter referred to as PCC codec), are mixed, as in PCC.

[0112] First, we will explain the encoding unit 4670, which has the functions of both the first encoding unit 4630 and the second encoding unit 4650 described above, and the decoding unit 4680, which has the functions of both the first decoding unit 4640 and the second decoding unit 4660.

[0113] 14 is a block diagram of encoding section 4670 according to this embodiment. This encoding section 4670 includes first encoding section 4630 and second encoding section 4650 described above, and a multiplexing section 4671. Multiplexing section 4671 multiplexes the encoded data generated by first encoding section 4630 and the encoded data generated by second encoding section 4650, and outputs the obtained encoded data.

[0114] 15 is a block diagram of a decoding unit 4680 according to this embodiment. This decoding unit 4680 includes the first decoding unit 4640 and second decoding unit 4660 described above, and a demultiplexing unit 4681. The demultiplexing unit 4681 extracts, from input coded data, coded data coded using the first coding method and coded data coded using the second coding method. The demultiplexing unit 4681 outputs the coded data coded using the first coding method to the first decoding unit 4640, and outputs the coded data coded using the second coding method to the second decoding unit 4660.

[0115] With the above configuration, the encoding unit 4670 can encode point cloud data by selectively using the first encoding method or the second encoding method. Furthermore, the decoding unit 4680 can decode encoded data encoded using the first encoding method, encoded data encoded using the second encoding method, and encoded data encoded using both the first encoding method and the second encoding method.

[0116] For example, the encoding unit 4670 may switch the encoding method (the first encoding method and the second encoding method) in units of point cloud data or in units of frames. Furthermore, the encoding unit 4670 may switch the encoding method in units that can be encoded.

[0117] The encoding unit 4670 generates, for example, encoded data (encoded stream) including identification information of the PCC codec.

[0118] The demultiplexing unit 4681 included in the decoding unit 4680 identifies the data using, for example, PCC codec identification information. If the data is data coded using a first coding method, the demultiplexing unit 4681 outputs the data to the first decoding unit 4640. If the data is data coded using a second coding method, the demultiplexing unit 4681 outputs the data to the second decoding unit 4660.

[0119] In addition to the PCC codec identification information, the encoding unit 4670 may also send information indicating whether both encoding methods or one of the encoding methods was used as control information.

[0120] Next, the encoding process according to this embodiment will be described. Fig. 16 is a flowchart of the encoding process according to this embodiment. By using the PCC codec identification information, encoding process compatible with multiple codecs becomes possible.

[0121] First, the encoding unit 4670 encodes the PCC data using either one or both of the codecs of the first encoding method and the second encoding method (S4681).

[0122] If the codec used is the second encoding method (second encoding method in S4682), the encoding unit 4670 sets pcc_codec_type included in the NAL unit header to a value indicating that the data included in the payload of the NAL unit is data encoded using the second encoding method (S4683). Next, the encoding unit 4670 sets pcc_nal_unit_type in the NAL unit header to an identifier of the NAL unit for the second encoding method (S4684). Then, the encoding unit 4670 generates an NAL unit that has the set NAL unit header and includes encoded data in its payload. Then, the encoding unit 4670 transmits the generated NAL unit (S4685).

[0123] On the other hand, if the codec used is the first encoding method (first encoding method in S4682), the encoding unit 4670 sets pcc_codec_type included in the NAL unit header to a value indicating that the data included in the payload of the NAL unit is data encoded using the first encoding method (S4686). Next, the encoding unit 4670 sets pcc_nal_unit_type included in the NAL unit header to an identifier of the NAL unit for the first encoding method (S4687). Next, the encoding unit 4670 generates a NAL unit that has the set NAL unit header and includes encoded data in its payload. Then, the encoding unit 4670 transmits the generated NAL unit (S4685).

[0124] Next, the decoding process according to this embodiment will be described. Fig. 17 is a flowchart of the decoding process according to this embodiment. By using the PCC codec identification information, decoding process compatible with multiple codecs becomes possible.

[0125] First, the decoding unit 4680 receives an NAL unit (S4691). For example, this NAL unit is generated by the processing in the encoding unit 4670 described above.

[0126] Next, the decoding unit 4680 determines whether the pcc_codec_type included in the NAL unit header indicates the first encoding method or the second encoding method (S4692).

[0127] If pcc_codec_type indicates the second encoding method (second encoding method in S4692), the decoding unit 4680 determines that the data included in the payload of the NAL unit is data encoded using the second encoding method (S4693).The second decoding unit 4660 then identifies the data by determining that pcc_nal_unit_type included in the NAL unit header is an identifier of the NAL unit for the second encoding method (S4694).The decoding unit 4680 then decodes the PCC data using the decoding process for the second encoding method (S4695).

[0128] On the other hand, if pcc_codec_type indicates the first encoding method (first encoding method in S4692), the decoding unit 4680 determines that the data included in the payload of the NAL unit is data encoded using the first encoding method (S4696).The decoding unit 4680 then identifies the data by determining that pcc_nal_unit_type included in the NAL unit header is an identifier of the NAL unit for the first encoding method (S4697).The decoding unit 4680 then decodes the PCC data using the decoding process for the first encoding method (S4698).

[0129] As described above, a three-dimensional data encoding device according to one embodiment of the present disclosure generates an encoded stream by encoding three-dimensional data (e.g., point cloud data), and stores information indicating the encoding method used for the encoding, either the first encoding method or the second encoding method (e.g., codec identification information), in control information (e.g., a parameter set) of the encoded stream.

[0130] According to this, when decoding an encoded stream generated by the three-dimensional data encoding device, the three-dimensional data decoding device can determine the encoding method used for encoding using the information stored in the control information, and therefore the three-dimensional data decoding device can correctly decode the encoded stream even when multiple encoding methods are used.

[0131] For example, the three-dimensional data includes position information. In the encoding step, the three-dimensional data encoding device encodes the position information. In the storing step, the three-dimensional data encoding device stores, in control information for the position information, information indicating which of the first encoding method and the second encoding method was used to encode the position information.

[0132] For example, the three-dimensional data includes position information and attribute information. In the encoding step, the three-dimensional data encoding device encodes the position information and the attribute information. In the storing step, the three-dimensional data encoding device stores, in control information for the position information, information indicating which of the first encoding method and the second encoding method was used to encode the position information, and stores, in control information for the attribute information, information indicating which of the first encoding method and the second encoding method was used to encode the attribute information.

[0133] This allows different encoding methods to be used for the position information and the attribute information, thereby improving encoding efficiency.

[0134] For example, the three-dimensional data encoding method further stores the encoded stream in one or more units (for example, NAL units).

[0135] For example, the unit has a format common to the first encoding method and the second encoding method, and includes information indicating the type of data contained in the unit, which information has independent definitions in the first encoding method and the second encoding method (e.g., pcc_nal_unit_type).

[0136] For example, the unit has a format that is independent between the first encoding method and the second encoding method, and includes information indicating the type of data contained in the unit, which has a definition that is independent between the first encoding method and the second encoding method (e.g., codec1_nal_unit_type or codec2_nal_unit_type).

[0137] For example, the unit has a format common to the first encoding method and the second encoding method, and includes information indicating the type of data contained in the unit, which information has a definition common to the first encoding method and the second encoding method (e.g., pcc_nal_unit_type).

[0138] For example, the three-dimensional data encoding device includes a processor and a memory, and the processor performs the above-mentioned processing using the memory.

[0139] Furthermore, the three-dimensional data decoding device according to this embodiment determines the encoding method used to encode the encoded stream based on information (e.g., codec identification information) indicating which of the first and second encoding methods was used to encode the three-dimensional data, which is included in control information (e.g., a parameter set) of the encoded stream generated by encoding the three-dimensional data, and decodes the encoded stream using the determined encoding method.

[0140] According to this, when decoding an encoded stream, the three-dimensional data decoding device can determine the encoding method used for encoding using the information stored in the control information, and therefore the three-dimensional data decoding device can correctly decode the encoded stream even when multiple encoding methods are used.

[0141] For example, the three-dimensional data includes position information, and the encoded stream includes encoded data of the position information. In the determination, the three-dimensional data decoding device determines the encoding method used to encode the position information based on information indicating which of the first encoding method and the second encoding method was used to encode the position information, the information being included in control information of the position information included in the encoded stream. In the decoding, the three-dimensional data decoding device decodes the encoded data of the position information using the determined encoding method used to encode the position information.

[0142] For example, the three-dimensional data includes position information and attribute information, and the encoded stream includes encoded data of the position information and encoded data of the attribute information. In the determination, the three-dimensional data decoding device determines the encoding method used to encode the position information based on information, which of the first encoding method and the second encoding method was used to encode the position information, included in control information of the position information included in the encoded stream, and determines the encoding method used to encode the attribute information based on information, which of the first encoding method and the second encoding method was used to encode the attribute information, included in control information of the attribute information included in the encoded stream. In the decoding, the three-dimensional data decoding device decodes the encoded data of the position information using the determined encoding method used to encode the position information, and decodes the encoded data of the attribute information using the determined encoding method used to encode the attribute information.

[0143] This allows different encoding methods to be used for the position information and the attribute information, thereby improving encoding efficiency.

[0144] For example, the coded stream is stored in one or more units (for example, NAL units), and the three-dimensional data decoding device further obtains the coded stream from the one or more units.

[0145] For example, the unit has a format common to the first encoding method and the second encoding method, and includes information indicating the type of data contained in the unit, which information has independent definitions in the first encoding method and the second encoding method (e.g., pcc_nal_unit_type).

[0146] For example, the unit has a format that is independent between the first encoding method and the second encoding method, and includes information indicating the type of data contained in the unit, which has a definition that is independent between the first encoding method and the second encoding method (e.g., codec1_nal_unit_type or codec2_nal_unit_type).

[0147] For example, the unit has a format common to the first encoding method and the second encoding method, and includes information indicating the type of data contained in the unit, which information has a definition common to the first encoding method and the second encoding method (e.g., pcc_nal_unit_type).

[0148] For example, the three-dimensional data decoding device includes a processor and a memory, and the processor performs the above processing using the memory.

[0149] (Embodiment 2) In this embodiment, a method for storing NAL units in an ISOBMFF file will be described.

[0150] ISOBMFF (ISO based media file format) is a file format standard defined in ISO / IEC 14496-12. ISOBMFF is a media-independent standard that defines a format that can store multiplexed media such as video, audio, and text.

[0151] This section explains the basic structure (file) of ISOBMFF. The basic unit in ISOBMFF is a box. A box consists of type, length, and data, and a file is a collection of boxes of various types.

[0152] 18 is a diagram showing the basic structure (file) of ISOBMFF. An ISOBMFF file mainly includes boxes such as ftyp, which indicates the brand of the file using 4CC (four-character code), moov, which stores metadata such as control information, and mdat, which stores data.

[0153] Storing methods for each media type in ISOBMFF files are specified separately. For example, storage methods for AVC video and HEVC video are specified in ISO / IEC 14496-15. While it is conceivable to extend and use the functions of ISOBMFF to store or transmit PCC encoded data, there are no regulations yet for storing PCC encoded data in ISOBMFF files. Therefore, in this embodiment, a method for storing PCC encoded data in an ISOBMFF file will be described.

[0154] 19 is a diagram showing a protocol stack when NAL units common to PCC codecs are stored in an ISOBMFF file. Here, NAL units common to PCC codecs are stored in an ISOBMFF file. Although NAL units are common to PCC codecs, multiple PCC codecs are stored in the NAL unit, so it is desirable to define a storage method (Carriage of Codec1, Carriage of Codec2) according to each codec.

[0155] Next, a method for storing a common PCC NAL unit that supports multiple PCC codecs in an ISOBMFF file will be described. Fig. 20 is a diagram showing an example of storing a common PCC NAL unit in an ISOBMFF file using the storage method for codec 1 (Carriage of Codec1). Fig. 21 is a diagram showing an example of storing a common PCC NAL unit in an ISOBMFF file using the storage method for codec 2 (Carriage of Codec2).

[0156] Here, ftyp is important information for identifying the file format, and a different identifier is defined for ftyp for each codec. When PCC-encoded data encoded using a first encoding method (encoding system) is stored in a file, ftyp=pcc1 is set. When PCC-encoded data encoded using a second encoding method is stored in a file, ftyp=pcc2 is set.

[0157] Here, pcc1 indicates that PCC codec 1 (first encoding method) is used, and pcc2 indicates that PCC codec 2 (second encoding method) is used. In other words, pcc1 and pcc2 indicate that the data is PCC (coded data of three-dimensional data (point cloud data)), and also indicate the PCC codecs (first and second encoding methods).

[0158] A method for storing NAL units in an ISOBMFF file will be described below. The multiplexing unit analyzes the NAL unit header, and if pcc_codec_type=Codec1, writes pcc1 in ftyp of ISOBMFF.

[0159] Furthermore, the multiplexing unit analyzes the NAL unit header, and if pcc_codec_type=Codec2, writes pcc2 in ftyp of ISOBMFF.

[0160] Furthermore, if pcc_nal_unit_type is metadata, the multiplexing unit stores the NAL unit in a predetermined manner, for example, in moov or mdat. If pcc_nal_unit_type is data, the multiplexing unit stores the NAL unit in a predetermined manner, for example, in moov or mdat.

[0161] For example, the multiplexing unit may store the NAL unit size in the NAL unit, similar to HEVC.

[0162] This storage method enables the demultiplexer (system layer) to analyze the ftyp included in the file to determine whether the PCC-encoded data was encoded using the first encoding method or the second encoding method. Furthermore, as described above, by determining whether the PCC-encoded data was encoded using the first encoding method or the second encoding method, it is possible to extract encoded data encoded using one of the encoding methods from data containing a mixture of data encoded using both encoding methods. This reduces the amount of data transmitted when transmitting encoded data. Furthermore, this storage method allows a common data format to be used for the first encoding method and the second encoding method, without requiring different data (file) formats to be set.

[0163] In addition, when codec identification information is indicated in metadata of the system layer, such as ftyp in ISOBMFF, the multiplexing unit may store NAL units from which pcc_nal_unit_type has been deleted in an ISOBMFF file.

[0164] Next, the configuration and operation of the multiplexing unit provided in the three-dimensional data encoding system (three-dimensional data encoding device) according to this embodiment and the demultiplexing unit provided in the three-dimensional data decoding system (three-dimensional data decoding device) according to this embodiment will be described.

[0165] 22 is a diagram showing the configuration of the first multiplexing unit 4710. The first multiplexing unit 4710 includes a file conversion unit 4711 that generates multiplexed data (file) by storing the coded data and control information (NAL units) generated by the first coding unit 4630 in an ISOBMFF file. This first multiplexing unit 4710 is included in, for example, the multiplexing unit 4614 shown in FIG. 1.

[0166] 23 is a diagram showing the configuration of the first demultiplexing unit 4720. The first demultiplexing unit 4720 includes a file inverse conversion unit 4721 that acquires coded data and control information (NAL units) from multiplexed data (file) and outputs the acquired coded data and control information to the first decoding unit 4640. This first demultiplexing unit 4720 is included in the demultiplexing unit 4623 shown in FIG. 1, for example.

[0167] 24 is a diagram showing the configuration of the second multiplexing unit 4730. The second multiplexing unit 4730 includes a file conversion unit 4731 that generates multiplexed data (file) by storing the coded data and control information (NAL units) generated by the second coding unit 4650 in an ISOBMFF file. This second multiplexing unit 4730 is included in, for example, the multiplexing unit 4614 shown in FIG. 1.

[0168] 25 is a diagram showing the configuration of the second demultiplexing unit 4740. The second demultiplexing unit 4740 includes a file inverse conversion unit 4741 that acquires coded data and control information (NAL units) from multiplexed data (file) and outputs the acquired coded data and control information to the second decoding unit 4660. This second demultiplexing unit 4740 is included in, for example, the demultiplexing unit 4623 shown in FIG.

[0169] 26 is a flowchart of the multiplexing process by the first multiplexing unit 4710. First, the first multiplexing unit 4710 analyzes pcc_codec_type included in the NAL unit header to determine whether the codec being used is the first encoding method or the second encoding method (S4701).

[0170] If pcc_codec_type indicates the second encoding method (second encoding method in S4702), the first multiplexing unit 4710 does not process the NAL unit (S4703).

[0171] On the other hand, if pcc_codec_type indicates the second encoding method (first encoding method in S4702), the first multiplexing unit 4710 writes pcc1 in ftyp (S4704). In other words, the first multiplexing unit 4710 writes information in ftyp indicating that data encoded using the first encoding method is stored in the file.

[0172] Next, the first multiplexing unit 4710 analyzes the pcc_nal_unit_type included in the NAL unit header, and stores the data in a box (moov, mdat, or the like) using a predetermined method according to the data type indicated by the pcc_nal_unit_type (S4705).Then, the first multiplexing unit 4710 creates an ISOBMFF file including the ftyp and the box (S4706).

[0173] 27 is a flowchart of the multiplexing process by the second multiplexing unit 4730. First, the second multiplexing unit 4730 analyzes pcc_codec_type included in the NAL unit header to determine whether the codec being used is the first encoding method or the second encoding method (S4711).

[0174] If pcc_unit_type indicates the second encoding method (second encoding method in S4712), the second multiplexing unit 4730 writes pcc2 in ftyp (S4713). In other words, the second multiplexing unit 4730 writes information in ftyp indicating that data encoded using the second encoding method is stored in the file.

[0175] Next, the second multiplexing unit 4730 analyzes pcc_nal_unit_type included in the NAL unit header, and stores the data in a box (moov, mdat, etc.) using a predetermined method according to the data type indicated by pcc_nal_unit_type (S4714).Then, the second multiplexing unit 4730 creates an ISOBMFF file including the ftyp and the box (S4715).

[0176] On the other hand, if pcc_unit_type indicates the first encoding method (first encoding method in S4712), the second multiplexing unit 4730 does not process the NAL unit (S4716).

[0177] Note that the above process shows an example in which PCC data is encoded using either the first encoding method or the second encoding method. The first multiplexing unit 4710 and the second multiplexing unit 4730 store the desired NAL unit in a file by identifying the codec type of the NAL unit. Note that if PCC codec identification information is included in addition to the NAL unit header, the first multiplexing unit 4710 and the second multiplexing unit 4730 may identify the codec type (first encoding method or second encoding method) in steps S4701 and S4711 using the PCC codec identification information included in addition to the NAL unit header.

[0178] Furthermore, when storing data in a file in steps S4706 and S4714, the first multiplexing unit 4710 and the second multiplexing unit 4730 may delete pcc_nal_unit_type from the NAL unit header before storing the data in the file.

[0179] 28 is a flowchart showing the processing by the first demultiplexing unit 4720 and the first decoding unit 4640. First, the first demultiplexing unit 4720 analyzes ftyp included in the ISOBMFF file (S4721). If the codec indicated by ftyp is the second encoding method (pcc2) (second encoding method in S4722), the first demultiplexing unit 4720 determines that the data included in the payload of the NAL unit is data encoded using the second encoding method (S4723). The first demultiplexing unit 4720 then conveys the result of this determination to the first decoding unit 4640. The first decoding unit 4640 does not process the NAL unit (S4724).

[0180] On the other hand, if the codec indicated by ftyp is the first encoding method (pcc1) (first encoding method in S4722), the first demultiplexing unit 4720 determines that the data included in the payload of the NAL unit is data encoded using the first encoding method (S4725). In addition, the first demultiplexing unit 4720 conveys the result of this determination to the first decoding unit 4640.

[0181] The first decoding unit 4640 identifies the data by determining that the pcc_nal_unit_type included in the NAL unit header is an identifier of the NAL unit for the first encoding method (S4726).Then, the first decoding unit 4640 decodes the PCC data using the decoding process for the first encoding method (S4727).

[0182] 29 is a flowchart showing the processing by the second demultiplexing unit 4740 and the second decoding unit 4660. First, the second demultiplexing unit 4740 analyzes ftyp included in the ISOBMFF file (S4731). If the codec indicated by ftyp is the second encoding method (pcc2) (second encoding method in S4732), the second demultiplexing unit 4740 determines that the data included in the payload of the NAL unit is data encoded using the second encoding method (S4733). The second demultiplexing unit 4740 also conveys the result of this determination to the second decoding unit 4660.

[0183] The second decoding unit 4660 identifies the data by determining that the pcc_nal_unit_type included in the NAL unit header is an identifier of the NAL unit for the second encoding method (S4734).Then, the second decoding unit 4660 decodes the PCC data using the decoding process for the second encoding method (S4735).

[0184] On the other hand, if the codec indicated by ftyp is the first encoding method (pcc1) (first encoding method in S4732), the second demultiplexing unit 4740 determines that the data included in the payload of the NAL unit is data encoded using the first encoding method (S4736). The second demultiplexing unit 4740 also conveys the result of this determination to the second decoding unit 4660. The second decoding unit 4660 does not process the NAL unit (S4737).

[0185] In this way, for example, by identifying the codec type of the NAL unit in the first demultiplexing unit 4720 or the second demultiplexing unit 4740, the codec type can be identified at an early stage. Furthermore, desired NAL units can be input to the first decoding unit 4640 or the second decoding unit 4660, and unnecessary NAL units can be removed. In this case, the process of analyzing codec identification information may become unnecessary in the first decoding unit 4640 or the second decoding unit 4660. Note that the first decoding unit 4640 or the second decoding unit 4660 may again refer to the NAL unit type and perform the process of analyzing codec identification information.

[0186] In addition, if the first multiplexing unit 4710 or the second multiplexing unit 4730 removes the pcc_nal_unit_type from the NAL unit header, the first demultiplexing unit 4720 or the second demultiplexing unit 4740 may add the pcc_nal_unit_type to the NAL unit and then output it to the first decoding unit 4640 or the second decoding unit 4660.

[0187] (Embodiment 3) This embodiment will describe a multiplexing unit and a demultiplexing unit corresponding to the encoding unit 4670 and decoding unit 4680 that support multiple codecs, as described in Embodiment 1. Fig. 30 shows the configurations of the encoding unit 4670 and third multiplexing unit 4750 according to this embodiment.

[0188] The encoding unit 4670 encodes the point cloud data using either or both of a first encoding method and a second encoding method. The encoding unit 4670 may switch the encoding method (the first encoding method and the second encoding method) for each point cloud data unit or for each frame unit. The encoding unit 4670 may also switch the encoding method for each encoding unit.

[0189] The encoding unit 4670 generates encoded data (encoded stream) including identification information of the PCC codec.

[0190] The third multiplexing unit 4750 includes a file conversion unit 4751. The file conversion unit 4751 converts the NAL units output from the encoding unit 4670 into a PCC data file. The file conversion unit 4751 analyzes the codec identification information included in the NAL unit header and determines whether the PCC-encoded data is data encoded using a first encoding method, data encoded using a second encoding method, or data encoded using both methods. The file conversion unit 4751 writes a brand name that can identify the codec in ftyp. For example, to indicate that the data has been encoded using both methods, pcc3 is written in ftyp.

[0191] If the encoding unit 4670 describes PCC codec identification information outside the NAL unit, the file conversion unit 4751 may use this identification information to determine the PCC codec (encoding method).

[0192] FIG. 31 shows the configuration of the third demultiplexing unit 4760 and the decoding unit 4680 according to the present embodiment.

[0193] The third demultiplexing unit 4760 includes a file inverse conversion unit 4761. The file inverse conversion unit 4761 analyzes the ftyp included in the file and determines whether the PCC encoded data is data encoded using the first encoding method, data encoded using the second encoding method, or data encoded using both methods.

[0194] When the PCC-encoded data is encoded using one of the encoding methods, the data is input to the corresponding decoding unit out of the first decoding unit 4640 and the second decoding unit 4660, and the data is not input to the other decoding unit. When the PCC-encoded data is encoded using both encoding methods, the data is input to a decoding unit 4680 that supports both methods.

[0195] The decoding unit 4680 decodes the PCC encoded data using either or both of the first encoding method and the second encoding method.

[0196] FIG. 32 is a flowchart showing processing by the third multiplexing section 4750 according to this embodiment.

[0197] First, the third multiplexing unit 4750 analyzes the pcc_codec_type included in the NAL unit header to determine whether the codec being used is the first encoding method, the second encoding method, or both the first and second encoding methods (S4741).

[0198] If the second encoding method is used (Yes in S4742 and the second encoding method in S4743), the third multiplexing unit 4750 writes pcc2 in ftyp (S4744). That is, the third multiplexing unit 4750 writes information indicating that data encoded using the second encoding method is stored in the file in ftyp.

[0199] Next, the third multiplexing unit 4750 analyzes pcc_nal_unit_type included in the NAL unit header, and stores the data in a box (moov, mdat, etc.) using a predetermined method according to the data type indicated by pcc_unit_type (S4745).Then, the third multiplexing unit 4750 creates an ISOBMFF file including the ftyp and the box (S4746).

[0200] On the other hand, if the first encoding method is used (Yes in S4742 and the first encoding method in S4743), the third multiplexing unit 4750 writes pcc1 in ftyp (S4747). That is, the third multiplexing unit 4750 writes information indicating that data encoded using the first encoding method is stored in the file in ftyp.

[0201] Next, the third multiplexing unit 4750 analyzes pcc_nal_unit_type included in the NAL unit header, and stores the data in a box (moov, mdat, or the like) using a predetermined method according to the data type indicated by pcc_unit_type (S4748).Then, the third multiplexing unit 4750 creates an ISOBMFF file including the ftyp and the box (S4746).

[0202] On the other hand, if both the first encoding method and the second encoding method are used (No in S4742), the third multiplexing unit 4750 writes pcc3 in ftyp (S4749). That is, the third multiplexing unit 4750 writes information in ftyp indicating that data encoded using both encoding methods is stored in the file.

[0203] Next, the third multiplexing unit 4750 analyzes pcc_nal_unit_type included in the NAL unit header, and stores the data in a box (moov, mdat, etc.) using a predetermined method according to the data type indicated by pcc_unit_type (S4750).Then, the third multiplexing unit 4750 creates an ISOBMFF file including the ftyp and the box (S4746).

[0204] 33 is a flowchart showing the processing by the third demultiplexing unit 4760 and the decoding unit 4680. First, the third demultiplexing unit 4760 analyzes ftyp included in the ISOBMFF file (S4761). If the codec indicated by ftyp is the second encoding method (pcc2) (Yes in S4762 and the second encoding method in S4763), the third demultiplexing unit 4760 determines that the data included in the payload of the NAL unit is data encoded using the second encoding method (S4764). The third demultiplexing unit 4760 then conveys the result of this determination to the decoding unit 4680.

[0205] The decoding unit 4680 identifies the data by determining that the pcc_nal_unit_type included in the NAL unit header is an identifier of the NAL unit for the second encoding method (S4765).The decoding unit 4680 then decodes the PCC data using the decoding process for the second encoding method (S4766).

[0206] On the other hand, if the codec indicated by ftyp is the first encoding method (pcc1) (Yes in S4762 and the first encoding method in S4763), the third demultiplexing unit 4760 determines that the data included in the payload of the NAL unit is data encoded using the first encoding method (S4767). The third demultiplexing unit 4760 also conveys the result of this determination to the decoding unit 4680.

[0207] The decoding unit 4680 identifies the data by determining that the pcc_nal_unit_type included in the NAL unit header is an identifier of the NAL unit for the first encoding method (S4768).The decoding unit 4680 then decodes the PCC data using the decoding process for the first encoding method (S4769).

[0208] On the other hand, if ftyp indicates that both encoding methods are used (pcc3) (No in S4762), the third demultiplexing unit 4760 determines that the data included in the payload of the NAL unit is data encoded using both the first encoding method and the second encoding method (S4770). The third demultiplexing unit 4760 also conveys the result of this determination to the decoding unit 4680.

[0209] The decoding unit 4680 identifies the data by determining that pcc_nal_unit_type included in the NAL unit header is an identifier of the NAL unit for the codec described in pcc_codec_type (S4771). Then, the decoding unit 4680 decodes the PCC data using the decoding processes of both encoding methods (S4772). That is, the decoding unit 4680 decodes data encoded using the first encoding method using the decoding process of the first encoding method, and decodes data encoded using the second encoding method using the decoding process of the second encoding method.

[0210] Modifications of this embodiment will be described below. As the brand type indicated in ftyp, the following types may be indicated by the identification information. Also, a combination of the following types may be indicated by the identification information.

[0211] The identification information may indicate whether the object in the original data before PCC encoding is a point cloud with a restricted area or a large-scale point cloud with an unrestricted area such as map information.

[0212] The identification information may indicate whether the original data before PCC encoding is a static object or a dynamic object.

[0213] As described above, the identification information may indicate whether the PCC encoded data is data encoded using a first encoding method or data encoded using a second encoding method.

[0214] The identification information may indicate the algorithm used in the PCC encoding, where the algorithm is, for example, an encoding method that can be used in the first encoding method or the second encoding method.

[0215] The identification information may indicate differences in the storage method of PCC-encoded data in an ISOBMFF file. For example, the identification information may indicate whether the storage method used is for storage or for real-time transmission such as dynamic streaming.

[0216] Although the second and third embodiments have been described with reference to examples in which ISOBMFF is used as the file format, other formats may also be used. For example, a method similar to that of the present embodiment may also be used when storing PCC encoded data in MPEG-2 TS Systems, MPEG-DASH, MMT, or RMP.

[0217] Although the above example shows that metadata such as identification information is stored in ftyp, this metadata may be stored in a location other than ftyp. For example, this metadata may be stored in moov.

[0218] As described above, the three-dimensional data storage device (or the three-dimensional data multiplexing device, or the three-dimensional data encoding device) performs the processing shown in FIG.

[0219] First, the three-dimensional data storage device (including, for example, the first multiplexing unit 4710, the second multiplexing unit 4730, or the third multiplexing unit 4750) acquires one or more units (for example, NAL units) in which an encoded stream in which point cloud data has been encoded is stored (S4781). Next, the three-dimensional data storage device stores the one or more units in a file (for example, an ISOBMFF file) (S4782). Furthermore, in the storing step (S4782), the three-dimensional data storage device stores information (for example, pcc1, pcc2, or pcc3) indicating that the data stored in the file is data in which point cloud data has been encoded, in the control information (for example, ftyp) of the file.

[0220] This allows a device that processes a file generated by the three-dimensional data storage device to refer to the control information of the file and quickly determine whether the data stored in the file is encoded point cloud data, thereby reducing the processing load of the device and speeding up processing.

[0221] For example, the information further indicates which of the first and second encoding methods was used to encode the point cloud data. Note that the fact that the data stored in the file is encoded point cloud data and the encoding method of the first and second encoding methods used to encode the point cloud data may be indicated by a single piece of information or by different pieces of information.

[0222] This allows a device that processes a file created by the three-dimensional data storage device to quickly determine the codec used for the data stored in the file by referencing the file's control information, thereby reducing the processing load of the device or speeding up processing.

[0223] For example, the first encoding method is a method (GPCC) in which position information representing the positions of point cloud data as an N-ary tree (N is an integer greater than or equal to 2) and attribute information is encoded using the position information, and the second encoding method is a method (VPCC) in which a two-dimensional image is generated from the point cloud data and the two-dimensional image is encoded using a video encoding method.

[0224] For example, the file conforms to ISOBMFF (ISO based media file format).

[0225] For example, the three-dimensional data storage device includes a processor and a memory, and the processor uses the memory to perform the above processing.

[0226] As described above, the three-dimensional data acquisition device (or the three-dimensional data demultiplexing device, or the three-dimensional data decoding device) performs the processing shown in FIG.

[0227] The three-dimensional data acquisition device (including, for example, the first demultiplexing unit 4720, the second demultiplexing unit 4740, or the third demultiplexing unit 4760) acquires a file (for example, an ISOBMFF file) that stores one or more units (for example, NAL units) in which an encoded stream in which point cloud data is encoded is stored (S4791). Next, the three-dimensional data acquisition device acquires one or more units from the file (S4792). In addition, the control information of the file (for example, ftyp) includes information (for example, pcc1, pcc2, or pcc3) that indicates that the data stored in the file is data in which point cloud data is encoded.

[0228] For example, the three-dimensional data acquisition device refers to the information and determines whether the data stored in the file is encoded point cloud data. Furthermore, if the three-dimensional data acquisition device determines that the data stored in the file is encoded point cloud data, it generates point cloud data by decoding the encoded point cloud data included in one or more units. Alternatively, if the three-dimensional data acquisition device determines that the data stored in the file is encoded point cloud data, it outputs (notifies) information indicating that the data included in one or more units is encoded point cloud data to a downstream processing unit (e.g., the first decoding unit 4640, the second decoding unit 4660, or the decoding unit 4680).

[0229] This allows the 3D data acquisition device to refer to the control information of the file and quickly determine whether the data stored in the file is encoded point cloud data, thereby reducing the processing load of the 3D data acquisition device or a downstream device and increasing the processing speed.

[0230] For example, the information further indicates the encoding method used for the encoding, either the first encoding method or the second encoding method. Note that the fact that the data stored in the file is data obtained by encoding point cloud data and the encoding method used for encoding the point cloud data, either the first encoding method or the second encoding method, may be indicated by a single piece of information or by different pieces of information.

[0231] This allows the 3D data acquisition device to refer to the control information of the file and quickly determine the codec used for the data stored in the file, thereby reducing the processing load of the 3D data acquisition device or a downstream device and increasing the processing speed.

[0232] For example, based on the information, the three-dimensional data acquisition device acquires data encoded using one of the encoding methods from encoded point cloud data that includes data encoded using the first encoding method and data encoded using the second encoding method.

[0233] For example, the first encoding method is a method (GPCC) in which position information representing the positions of point cloud data as an N-ary tree (N is an integer greater than or equal to 2) and attribute information is encoded using the position information, and the second encoding method is a method (VPCC) in which a two-dimensional image is generated from the point cloud data and the two-dimensional image is encoded using a video encoding method.

[0234] For example, the file conforms to ISOBMFF (ISO based media file format).

[0235] For example, the three-dimensional data acquisition device includes a processor and a memory, and the processor performs the above-mentioned processing using the memory.

[0236] (Fourth embodiment) In this embodiment, the types of coded data (position information (Geometry), attribute information (Attribute), additional information (Metadata)) generated by the first coding unit 4630 or the second coding unit 4650 described above, a method for generating the additional information (Metadata), and multiplexing processing in the multiplexing unit will be described. Note that the additional information (Metadata) may also be referred to as a parameter set or control information.

[0237] In this embodiment, the dynamic object (three-dimensional point cloud data that changes over time) described in Figure 4 will be used as an example, but a similar method may also be used in the case of a static object (three-dimensional point cloud data at any time).

[0238] 36 is a diagram showing the configurations of an encoding unit 4801 and a multiplexing unit 4802 included in the three-dimensional data encoding device according to this embodiment. The encoding unit 4801 corresponds to, for example, the first encoding unit 4630 or the second encoding unit 4650 described above. The multiplexing unit 4802 corresponds to the multiplexing unit 4634 or 46456 described above.

[0239] The encoding unit 4801 encodes point cloud data of multiple PCC (Point Cloud Compression) frames, and generates encoded data (Multiple Compressed Data) of multiple pieces of position information, attribute information, and additional information.

[0240] The multiplexing unit 4802 converts data of multiple data types (position information, attribute information, and additional information) into NAL units, thereby converting the data into a data structure that takes into account data access in the decoding device.

[0241] 37 is a diagram showing an example of the structure of coded data generated by coding unit 4801. Arrows in the diagram indicate dependencies related to the decoding of coded data, with the source of the arrow depending on the data at the end of the arrow. In other words, the decoding device decodes the data at the end of the arrow and uses the decoded data to decode the data at the end of the arrow. In other words, dependency means that the data on which the dependency is based is referenced (used) in the processing (encoding, decoding, etc.) of the data on which the dependency is based.

[0242] First, the process of generating encoded data of position information will be described. The encoding unit 4801 generates encoded position data (compressed geometry data) for each frame by encoding the position information of each frame. The encoded position data is represented by G(i), where i indicates the frame number, the time of the frame, etc.

[0243] The encoding unit 4801 also generates a position parameter set (GPS(i)) corresponding to each frame. The position parameter set includes parameters that can be used to decode the encoded position data. The encoded position data for each frame depends on the corresponding position parameter set.

[0244] Furthermore, encoded position data consisting of multiple frames is defined as a position sequence (Geometry Sequence). The encoding unit 4801 generates a position sequence parameter set (Geometry Sequence PS: also referred to as position SPS) that stores parameters commonly used in decoding processes for multiple frames in the position sequence. The position sequence depends on the position SPS.

[0245] Next, the process of generating coded data of attribute information will be described. The coding unit 4801 generates coded attribute data (Compressed Attribute Data) for each frame by coding the attribute information of each frame. The coded attribute data is represented by A(i). Also, Fig. 37 shows an example in which attribute X and attribute Y exist, and the coded attribute data of attribute X is represented by AX(i) and the coded attribute data of attribute Y is represented by AY(i).

[0246] The encoding unit 4801 also generates an attribute parameter set (APS(i)) corresponding to each frame. The attribute parameter set for attribute X is represented as AXPS(i), and the attribute parameter set for attribute Y is represented as AYPS(i). The attribute parameter set includes parameters that can be used to decode encoded attribute information. The encoded attribute data depends on the corresponding attribute parameter set.

[0247] Furthermore, encoded attribute data consisting of multiple frames is defined as an attribute sequence. The encoding unit 4801 generates an attribute sequence parameter set (Attribute Sequence PS: also referred to as attribute SPS) that stores parameters commonly used in decoding processes for multiple frames in the attribute sequence. The attribute sequence depends on the attribute SPS.

[0248] Furthermore, in the first encoding method, the encoded attribute data depends on the encoded position data.

[0249] 37 shows an example in which two types of attribute information (attribute X and attribute Y) exist. When there are two types of attribute information, for example, two encoding units generate respective data and metadata. Also, for example, an attribute sequence is defined for each type of attribute information, and an attribute SPS is generated for each type of attribute information.

[0250] Note that, while FIG. 37 shows an example in which there is one type of position information and two types of attribute information, the present invention is not limited to this, and there may be one type of attribute information, or three or more types. In this case, encoded data can be generated using a similar method. Furthermore, in the case of point cloud data that does not have attribute information, the attribute information may not be necessary. In this case, the encoding unit 4801 does not need to generate a parameter set related to the attribute information.

[0251] Next, the process of generating additional information (metadata) will be described. The encoding unit 4801 generates a PCC Stream PS (also referred to as stream PS), which is a parameter set for the entire PCC stream. The encoding unit 4801 stores, in the stream PS, parameters that can be used in common for decoding processes for one or more position sequences and one or more attribute sequences. For example, the stream PS includes identification information indicating the codec for the point cloud data, information indicating the algorithm used for encoding, and the like. The position sequence and attribute sequence depend on the stream PS.

[0252] Next, the access unit and GOF will be explained. In this embodiment, the concepts of the access unit (AU) and GOF (Group of Frame) are newly introduced.

[0253] An access unit is a basic unit for accessing data during decoding, and is composed of one or more pieces of data and one or more pieces of metadata. For example, an access unit is composed of position information at the same time and one or more pieces of attribute information. A GOF is a random access unit and is composed of one or more access units.

[0254] The encoding unit 4801 generates an access unit header (AU Header) as identification information indicating the beginning of an access unit. The encoding unit 4801 stores parameters related to the access unit in the access unit header. For example, the access unit header includes the configuration or information of the coded data included in the access unit. The access unit header also includes parameters commonly used for the data included in the access unit, such as parameters related to decoding of the coded data.

[0255] Instead of an access unit header, the encoding unit 4801 may generate an access unit delimiter that does not include parameters related to the access unit. This access unit delimiter is used as identification information indicating the start of the access unit. The decoding device identifies the start of the access unit by detecting the access unit header or the access unit delimiter.

[0256] Next, the generation of identification information for the start of a GOF will be described. The encoding unit 4801 generates a GOF header as identification information that indicates the start of a GOF. The encoding unit 4801 stores parameters related to the GOF in the GOF header. For example, the GOF header includes the configuration or information of the coded data included in the GOF. The GOF header also includes parameters commonly used for the data included in the GOF, such as parameters related to the decoding of the coded data.

[0257] Instead of a GOF header, the encoding unit 4801 may generate a GOF delimiter that does not include parameters related to the GOF. This GOF delimiter is used as identification information that indicates the beginning of the GOF. The decoding device identifies the beginning of the GOF by detecting the GOF header or the GOF delimiter.

[0258] In PCC encoded data, for example, an access unit is defined as a PCC frame unit, and a decoding device accesses a PCC frame based on identification information at the beginning of the access unit.

[0259] Also, for example, GOF is defined as one random access unit. A decoding device accesses the random access unit based on the identification information at the beginning of the GOF. For example, if PCC frames are not dependent on each other and can be decoded independently, the PCC frames may be defined as the random access unit.

[0260] It should be noted that two or more PCC frames may be allocated to one access unit, and multiple random access units may be allocated to one GOF.

[0261] The encoding unit 4801 may also define and generate parameter sets or metadata other than those described above. For example, the encoding unit 4801 may generate SEI (Supplemental Enhancement Information) that stores parameters (optional parameters) that may not necessarily be used during decoding.

[0262] Next, the structure of coded data and the method of storing coded data in NAL units will be described.

[0263] For example, a data format is defined for each type of coded data. Figure 38 shows examples of coded data and NAL units.

[0264] For example, as shown in Fig. 38, the coded data includes a header and a payload. The coded data may include length information indicating the length (amount of data) of the coded data, the header, or the payload. The coded data may not include a header.

[0265] The header includes, for example, identification information for identifying the data, such as the data type or frame number.

[0266] The header includes, for example, identification information indicating a reference relationship. This identification information is stored in the header when, for example, there is a dependency relationship between data, and is information for referencing the reference destination from the reference source. For example, the header of the reference destination includes identification information for identifying the data. The header of the reference source includes identification information indicating the reference destination.

[0267] If the reference destination or the reference source can be identified or derived from other information, the identification information for specifying the data or the identification information indicating the reference relationship may be omitted.

[0268] The multiplexing unit 4802 stores the coded data in the payload of the NAL unit. The NAL unit header includes pcc_nal_unit_type, which is information identifying the coded data. Figure 39 shows an example of the semantics of pcc_nal_unit_type.

[0269] As shown in Fig. 39, when pcc_codec_type is codec 1 (Codec1: first encoding method), values ​​0 to 10 of pcc_nal_unit_type are assigned to the encoded position data (Geometry), encoded attribute X data (AttributeX), encoded attribute Y data (AttributeY), position PS (Geom.PS), attribute XPS (AttrX.PS), attribute YPS (AttrX.PS), position SPS (Geometry Sequence PS), attribute XSPS (AttributeX Sequence PS), attribute YSPS (AttributeY Sequence PS), AU header (AU Header), and GOF header (GOF Header) in codec 1. Values ​​11 and above are assigned as spares for codec 1.

[0270] When pcc_codec_type is Codec2 (Codec2: second encoding method), values ​​0 to 2 of pcc_nal_unit_type are assigned to codec data A (DataA), metadata A (MetaDataA), and metadata B (MetaDataB). Values ​​3 and above are assigned as spares for Codec2.

[0271] Next, the data transmission order will be explained. The following explains the restrictions on the transmission order of NAL units.

[0272] The multiplexing unit 4802 collectively transmits NAL units in units of GOF or AU. The multiplexing unit 4802 places a GOF header at the beginning of a GOF, and places an AU header at the beginning of an AU.

[0273] The multiplexing unit 4802 may allocate a sequence parameter set (SPS) for each AU so that the decoding device can decode from the next AU even if data is lost due to packet loss or the like.

[0274] If the coded data has a dependency relationship related to decoding, the decoding device decodes the referenced data first, and then decodes the referenced data. In order to enable the decoding device to decode the data in the order in which it was received without rearranging the data, the multiplexing unit 4802 sends the referenced data first.

[0275] 40 is a diagram showing examples of the transmission order of NAL units, and shows three examples: position information priority, parameter priority, and data integration.

[0276] The location information priority transmission order is an example in which information related to location information and information related to attribute information are transmitted together. In this transmission order, the transmission of information related to location information is completed earlier than the transmission of information related to attribute information.

[0277] For example, by using this transmission order, a decoding device that does not decode attribute information may be able to set a time during which it does not process the attribute information by ignoring the decoding of the attribute information. Also, for example, in the case of a decoding device that wants to decode position information quickly, it may be able to decode the position information more quickly by obtaining the encoded data of the position information early.

[0278] In FIG. 40, the attributes XSPS and YSPS are combined and written as the attribute SPS, but the attributes XSPS and YSPS may be arranged separately.

[0279] In the parameter set priority sending order, the parameter sets are sent first and the data is sent later.

[0280] As long as the NAL unit transmission order constraints are met as described above, the multiplexing unit 4802 may transmit NAL units in any order. For example, order identification information may be defined, and the multiplexing unit 4802 may have the function of transmitting NAL units in multiple order patterns. For example, the NAL unit order identification information may be stored in the stream PS.

[0281] The three-dimensional data decoding device may perform decoding based on the order identification information. The three-dimensional data decoding device may instruct the three-dimensional data encoding device on a desired transmission order, and the three-dimensional data encoding device (multiplexing unit 4802) may control the transmission order in accordance with the instructed transmission order.

[0282] The multiplexing unit 4802 may generate coded data that merges multiple functions, as long as the data transmission order is within the constraints of the transmission order, such as the transmission order of the integrated data. For example, as shown in Fig. 40, the GOF header and the AU header may be integrated, or the AXPS and the AYPS may be integrated. In this case, an identifier indicating that the data has multiple functions is defined in pcc_nal_unit_type.

[0283] A modified example of this embodiment will be described below. PS has levels, such as a frame-level PS, a sequence-level PS, and a PCC sequence-level PS, and if the PCC sequence level is the higher level and the frame level is the lower level, the following method may be used to store parameters.

[0284] The default PS value is indicated in the higher PS. Also, if the value of the lower PS differs from the value of the higher PS, the PS value is indicated in the lower PS. Alternatively, the PS value is not written in the higher PS, but written in the lower PS. Alternatively, information on whether the PS value is to be written in the lower PS, the higher PS, or both is written in either the lower PS or the higher PS, or both. Alternatively, the lower PS may be merged with the higher PS. Alternatively, if the lower PS and the higher PS overlap, the multiplexing unit 4802 may omit sending one of them.

[0285] The encoding unit 4801 or the multiplexing unit 4802 may divide the data into slices or tiles and transmit the divided data. The divided data includes information for identifying the divided data, and parameters used to decode the divided data are included in the parameter set. In this case, an identifier indicating that the data stores data or parameters related to tiles or slices is defined in pcc_nal_unit_type.

[0286] The processing related to the order identification information will be explained below. Fig. 41 is a flowchart of processing by the three-dimensional data encoding device (the encoding unit 4801 and the multiplexing unit 4802) related to the transmission order of NAL units.

[0287] First, the three-dimensional data encoding device determines the transmission order of NAL units (position information priority or parameter set priority) (S4801). For example, the three-dimensional data encoding device determines the transmission order based on a specification from a user or an external device (e.g., a three-dimensional data decoding device).

[0288] If the determined transmission order is positional information priority (positional information priority in S4802), the three-dimensional data encoding device sets the order identification information included in the stream PS to positional information priority (S4803). That is, in this case, the order identification information indicates that the NAL units are to be transmitted in an order that prioritizes positional information. The three-dimensional data encoding device then transmits the NAL units in positional information priority order (S4804).

[0289] On the other hand, if the determined transmission order is parameter set priority (parameter set priority in S4802), the three-dimensional data encoding device sets the order identification information included in the stream PS to parameter set priority (S4805). That is, in this case, the order identification information indicates that the NAL units will be transmitted in parameter set priority order. Then, the three-dimensional data encoding device transmits the NAL units in parameter set priority order (S4806).

[0290] 42 is a flowchart of processing by the 3D data decoding device related to the transmission order of NAL units. First, the 3D data decoding device analyzes the order identification information included in the stream PS (S4811).

[0291] If the transmission order indicated by the order identification information is position information priority (position information priority in S4812), the three-dimensional data decoding device decodes the NAL units assuming that the transmission order of the NAL units is position information priority (S4813).

[0292] On the other hand, if the transmission order indicated by the order identification information is parameter set priority (parameter set priority in S4812), the three-dimensional data decoding device decodes the NAL units assuming that the transmission order of the NAL units is parameter set priority (S4814).

[0293] For example, if the three-dimensional data decoding device does not decode attribute information, in step S4813, it may acquire NAL units related to position information without acquiring all NAL units, and decode the position information from the acquired NAL units.

[0294] Next, the processing related to the generation of AUs and GOFs will be described. Fig. 43 is a flowchart of processing by the 3D data encoding device (the multiplexing unit 4802) related to the generation of AUs and GOFs in multiplexing NAL units.

[0295] First, the three-dimensional data encoding device determines the type of encoded data (S4821). Specifically, the three-dimensional data encoding device determines whether the encoded data to be processed is the first data of an AU, the first data of a GOF, or other data.

[0296] If the coded data is data at the start of a GOF (GOF start in S4822), the three-dimensional data coding device places a GOF header and an AU header at the start of the coded data belonging to the GOF to generate a NAL unit (S4823).

[0297] If the coded data is data at the beginning of an AU (AU beginning in S4822), the three-dimensional data coding device places an AU header at the beginning of the coded data belonging to the AU and generates a NAL unit (S4824).

[0298] If the encoded data is not at the beginning of a GOF or an AU (other than the beginning of a GOF or an AU in S4822), the three-dimensional data encoding device places the encoded data after the AU header of the AU to which the encoded data belongs and generates a NAL unit (S4825).

[0299] Next, a process for accessing AUs and GOFs will be described. Fig. 44 is a flowchart of a process performed by a three-dimensional data decoding device for accessing AUs and GOFs during demultiplexing of NAL units.

[0300] First, the three-dimensional data decoding device determines the type of coded data included in the NAL unit by analyzing the nal_unit_type included in the NAL unit (S4831). Specifically, the three-dimensional data decoding device determines whether the coded data included in the NAL unit is data at the beginning of an AU, data at the beginning of a GOF, or other data.

[0301] If the encoded data contained in the NAL unit is the data at the start of the GOF (start of GOF in S4832), the three-dimensional data decoding device determines that the NAL unit is the start position of random access, accesses the NAL unit, and starts the decoding process (S4833).

[0302] On the other hand, if the coded data contained in the NAL unit is data at the beginning of an AU (AU beginning in S4832), the three-dimensional data decoding device determines that the NAL unit is the beginning of an AU, accesses the data contained in the NAL unit, and decodes the AU (S4834).

[0303] On the other hand, if the coded data included in the NAL unit is neither the start of a GOF nor the start of an AU (other than the start of a GOF or an AU in S4832), the three-dimensional data decoding device does not process the NAL unit.

[0304] As described above, the three-dimensional data encoding device performs the processing shown in Fig. 45. The three-dimensional data encoding device encodes time-series three-dimensional data (for example, point cloud data of a dynamic object). The three-dimensional data includes position information and attribute information for each time.

[0305] First, the three-dimensional data encoding device encodes position information (S4841). Next, the three-dimensional data encoding device encodes the attribute information to be processed by referring to position information at the same time as the attribute information to be processed (S4842). Here, as shown in FIG. 37, the position information at the same time and the attribute information form an access unit (AU). In other words, the three-dimensional data encoding device encodes the attribute information to be processed by referring to position information included in the same access unit as the attribute information to be processed.

[0306] This allows the three-dimensional data encoding device to easily control references during encoding using the access unit, thereby reducing the amount of processing required for encoding.

[0307] For example, a three-dimensional data encoding device generates a bitstream including encoded position information (encoded position data), encoded attribute information (encoded attribute data), and information indicating the position information referenced by the attribute information to be processed.

[0308] For example, the bitstream includes a position parameter set (position PS) including control information for position information at each time, and an attribute parameter set (attribute PS) including control information for attribute information at each time.

[0309] For example, the bitstream includes a position sequence parameter set (position SPS) that includes control information common to position information at multiple times, and an attribute sequence parameter set (attribute SPS) that includes control information common to attribute information at multiple times.

[0310] For example, the bitstream includes a stream parameter set (stream PS) that includes control information common to position information at a plurality of times and attribute information at a plurality of times.

[0311] For example, the bitstream includes an access unit header (AU header) that contains control information that is common within an access unit.

[0312] For example, a three-dimensional data encoding device encodes a group of frames (GOF), which is made up of one or more access units, so that the GOF can be decoded independently. In other words, a GOF is a random access unit.

[0313] For example, the bitstream includes a GOF header that contains control information that is common within a GOF.

[0314] For example, the three-dimensional data encoding device includes a processor and a memory, and the processor performs the above-mentioned processing using the memory.

[0315] As described above, the three-dimensional data decoding device performs the processing shown in Fig. 46. The three-dimensional data decoding device decodes time-series three-dimensional data (for example, point cloud data of a dynamic object). The three-dimensional data includes position information and attribute information for each time. Position information and attribute information for the same time constitute an access unit (AU).

[0316] First, the three-dimensional data decoding device decodes the position information from the bit stream (S4851). That is, the three-dimensional data decoding device generates the position information by decoding the coded position information (coded position data) included in the bit stream.

[0317] Next, the three-dimensional data decoding device decodes the attribute information to be processed from the bit stream by referring to position information at the same time as the attribute information to be processed (S4852). That is, the three-dimensional data decoding device generates attribute information by decoding the coded attribute information (coded attribute data) included in the bit stream. At this time, the three-dimensional data decoding device refers to the decoded position information included in the same access unit as the attribute information.

[0318] This allows the three-dimensional data decoding device to easily control references during decoding using the access unit, thereby reducing the amount of processing required for the decoding process.

[0319] For example, the three-dimensional data decoding device acquires information indicating the location information of the reference destination of the attribute information to be processed from the bit stream, and decodes the attribute information to be processed by referring to the location information of the reference destination indicated in the acquired information.

[0320] For example, the bitstream includes a position parameter set (position PS) including control information for position information at each time, and an attribute parameter set (attribute PS) including control information for attribute information at each time. That is, the three-dimensional data decoding device decodes the position information at the processing target time using the control information included in the position parameter set for the processing target time, and decodes the attribute information at the processing target time using the control information included in the attribute parameter set for the processing target time.

[0321] For example, the bitstream includes a position sequence parameter set (position SPS) including control information common to position information at multiple times, and an attribute sequence parameter set (attribute SPS) including control information common to attribute information at multiple times. That is, the three-dimensional data decoding device decodes the position information at multiple times using the control information included in the position sequence parameter set, and decodes the attribute information at multiple times using the control information included in the attribute sequence parameter set.

[0322] For example, the bitstream includes a stream parameter set (stream PS) including control information common to position information at multiple times and attribute information at multiple times. That is, the three-dimensional data decoding device decodes the position information at multiple times and attribute information at multiple times using the control information included in the stream parameter set.

[0323] For example, the bitstream includes an access unit header (AU header) that includes common control information within the access unit. That is, the 3D data decoding device decodes the position information and attribute information included in the access unit using the control information included in the access unit header.

[0324] For example, a three-dimensional data decoding device independently decodes a group of frames (GOF), which is made up of one or more access units. In other words, a GOF is a random access unit.

[0325] For example, the bitstream includes a GOF header that includes control information common within a GOF. That is, the three-dimensional data decoding device decodes the position information and attribute information included in the GOF using the control information included in the GOF header.

[0326] For example, the three-dimensional data decoding device includes a processor and a memory, and the processor performs the above processing using the memory.

[0327] (Embodiment 5) HEVC coding has data division tools such as slicing or tiling to enable parallel processing in a decoding device, but PCC (Point Cloud Compression) coding does not yet have such tools.

[0328] In PCC, various data division methods are possible depending on parallel processing, compression efficiency, and compression algorithms. This section explains the definitions of slices and tiles, the data structure, and transmission and reception methods.

[0329] 47 is a block diagram showing the configuration of a first encoding unit 4910 included in the three-dimensional data encoding device according to this embodiment. The first encoding unit 4910 generates encoded data (encoded stream) by encoding point cloud data using a first encoding method (GPCC (Geometry based PCC)). The first encoding unit 4910 includes a division unit 4911, multiple position information encoding units 4912, multiple attribute information encoding units 4913, an additional information encoding unit 4914, and a multiplexing unit 4915.

[0330] The dividing unit 4911 divides the point cloud data to generate a plurality of pieces of divided data. Specifically, the dividing unit 4911 divides the space of the point cloud data into a plurality of subspaces to generate a plurality of pieces of divided data. Here, a subspace is one of a tile and a slice, or a combination of a tile and a slice. More specifically, the point cloud data includes position information, attribute information, and additional information. The dividing unit 4911 divides the position information into a plurality of pieces of divided position information, and divides the attribute information into a plurality of pieces of divided attribute information. The dividing unit 4911 also generates additional information related to the division.

[0331] The position information encoding units 4912 encode the plurality of pieces of divided position information to generate a plurality of pieces of encoded position information. For example, the position information encoding units 4912 process the plurality of pieces of divided position information in parallel.

[0332] The attribute information encoding units 4913 encode the divided attribute information to generate the coded attribute information For example, the attribute information encoding units 4913 process the divided attribute information in parallel.

[0333] The additional information encoding unit 4914 generates encoded additional information by encoding the additional information included in the point cloud data and the additional information related to the data division generated by the division unit 4911 at the time of division.

[0334] The multiplexing unit 4915 multiplexes multiple pieces of encoding position information, multiple pieces of encoding attribute information, and encoded additional information to generate encoded data (encoded stream), and transmits the generated encoded data. The encoded additional information is also used during decoding.

[0335] 47 shows an example in which there are two position information encoders 4912 and two attribute information encoders 4913, but the number of position information encoders 4912 and two attribute information encoders 4913 may each be one, or three or more. Furthermore, multiple pieces of divided data may be processed in parallel within the same chip, such as multiple cores within a CPU, or may be processed in parallel by cores on multiple chips, or may be processed in parallel by multiple cores on multiple chips.

[0336] 48 is a block diagram showing the configuration of the first decoding unit 4920. The first decoding unit 4920 restores the point cloud data by decoding coded data (coded stream) generated by coding the point cloud data using the first coding method (GPCC). The first decoding unit 4920 includes a demultiplexing unit 4921, multiple position information decoding units 4922, multiple attribute information decoding units 4923, an additional information decoding unit 4924, and a combining unit 4925.

[0337] The demultiplexing unit 4921 demultiplexes the coded data (coded stream) to generate a plurality of pieces of coding position information, a plurality of pieces of coding attribute information, and coded additional information.

[0338] The position information decoding units 4922 generate a plurality of pieces of divided position information by decoding the plurality of pieces of encoded position information. For example, the position information decoding units 4922 process the plurality of pieces of encoded position information in parallel.

[0339] The attribute information decoding units 4923 generate a plurality of pieces of divided attribute information by decoding the plurality of pieces of encoded attribute information. For example, the attribute information decoding units 4923 process the plurality of pieces of encoded attribute information in parallel.

[0340] The plurality of additional information decoders 4924 generate additional information by decoding the encoded additional information.

[0341] The combining unit 4925 generates position information by combining a plurality of pieces of divided position information using the additional information. The combining unit 4925 generates attribute information by combining a plurality of pieces of divided attribute information using the additional information.

[0342] 48 shows an example in which there are two position information decoding units 4922 and two attribute information decoding units 4923, but the number of position information decoding units 4922 and two attribute information decoding units 4923 may be one, or three or more. Furthermore, multiple pieces of divided data may be processed in parallel within the same chip, such as multiple cores within a CPU, or may be processed in parallel by cores on multiple chips, or may be processed in parallel by multiple cores on multiple chips.

[0343] Next, it will be described how the dividing unit 4911 has a configuration. Fig. 49 is a block diagram of the dividing unit 4911. The dividing unit 4911 includes a slice dividing unit 4931 (Slice Divider), a position information tile dividing unit 4932 (Geometry Tile Divider), and an attribute information tile dividing unit 4933 (Attribute Tile Divider).

[0344] The slice division unit 4931 generates a plurality of slice position information by dividing position information (Position (Geometry)) into slices. The slice division unit 4931 also generates a plurality of slice attribute information by dividing attribute information (Attribute) into slices. The slice division unit 4931 also outputs slice additional information (SliceMetaData) including information related to the slice division and information generated in the slice division.

[0345] The position information tile dividing unit 4932 divides a plurality of slice position information pieces into tiles to generate a plurality of pieces of divided position information pieces (a plurality of pieces of tile position information pieces). The position information tile dividing unit 4932 also outputs position tile additional information (Geometry Tile MetaData) including information related to the tile division of the position information pieces and information generated in the tile division of the position information pieces.

[0346] The attribute information tile dividing unit 4933 divides a plurality of slice attribute information pieces into tiles to generate a plurality of pieces of divided attribute information (a plurality of pieces of tile attribute information). The attribute information tile dividing unit 4933 also outputs attribute tile additional information (Attribute Tile MetaData) including information related to the tile division of the attribute information and information generated during the tile division of the attribute information.

[0347] The number of slices or tiles to be divided is equal to or greater than 1. In other words, division into slices or tiles does not have to be performed.

[0348] Although an example in which tile division is performed after slice division has been shown here, slice division may be performed after tile division. Furthermore, new division types may be defined in addition to slices and tiles, and division may be performed using three or more division types.

[0349] A method for dividing point cloud data will be described below. Fig. 50 is a diagram showing an example of division into slices and tiles.

[0350] First, the method of dividing into slices will be described. The dividing unit 4911 divides the three-dimensional point cloud data into arbitrary point clouds in slice units. In dividing into slices, the dividing unit 4911 does not divide the position information and attribute information that constitute a point, but divides the position information and attribute information together. In other words, the dividing unit 4911 divides into slices so that the position information and attribute information of an arbitrary point belong to the same slice. Note that, as long as this is followed, any number of divisions and any division method may be used. Furthermore, the minimum unit of division is a point. For example, the number of divisions for the position information and the attribute information is the same. For example, the three-dimensional point corresponding to the position information after dividing into slices and the three-dimensional point corresponding to the attribute information are included in the same slice.

[0351] Furthermore, the division unit 4911 generates slice additional information, which is additional information related to the number of divisions and the division method when dividing the slices. The slice additional information is the same for position information and attribute information. For example, the slice additional information includes information indicating the reference coordinate position, size, or side length of the bounding box after division. The slice additional information also includes information indicating the number of divisions, the division type, etc.

[0352] Next, a tile division method will be described. The division unit 4911 divides the data divided into slices into slice position information (G slices) and slice attribute information (A slices), and divides each of the slice position information and slice attribute information into tiles.

[0353] Although FIG. 50 shows an example of division using an octree structure, any number of divisions and any division method may be used.

[0354] Furthermore, the dividing unit 4911 may divide the position information and the attribute information using different division methods or the same division method. Furthermore, the dividing unit 4911 may divide a plurality of slices into tiles using different division methods or the same division method.

[0355] Furthermore, the dividing unit 4911 generates tile additional information related to the number of divisions and the division method when dividing tiles. The tile additional information (position tile additional information and attribute tile additional information) is independent of position information and attribute information. For example, the tile additional information includes information indicating the reference coordinate position, size, or side length of the bounding box after division. The tile additional information also includes information indicating the number of divisions, division type, etc.

[0356] Next, an example of a method for dividing point cloud data into slices or tiles will be described. The dividing unit 4911 may use a predetermined method as the method for dividing the point cloud data into slices or tiles, or may adaptively switch the method to be used depending on the point cloud data.

[0357] When dividing into slices, the dividing unit 4911 divides the three-dimensional space collectively based on the position information and attribute information. For example, the dividing unit 4911 determines the shape of an object and divides the three-dimensional space into slices according to the shape of the object. For example, the dividing unit 4911 extracts objects such as trees or buildings and divides the space into object units. For example, the dividing unit 4911 divides the space into slices so that one or more objects are entirely included in one slice. Alternatively, the dividing unit 4911 divides one object into multiple slices.

[0358] In this case, the encoding device may change the encoding method for each slice. For example, the encoding device may use a high-quality compression method for a specific object or a specific part of an object. In this case, the encoding device may store information indicating the encoding method for each slice in additional information (metadata).

[0359] Furthermore, the dividing unit 4911 may divide the image into slices based on map information or location information so that each slice corresponds to a predetermined coordinate space.

[0360] When dividing into tiles, the dividing unit 4911 divides the position information and the attribute information independently. For example, the dividing unit 4911 divides a slice into tiles according to the amount of data or the amount of processing. For example, the dividing unit 4911 determines whether the amount of data of a slice (for example, the number of three-dimensional points included in the slice) is greater than a predetermined threshold. If the amount of data of a slice is greater than the threshold, the dividing unit 4911 divides the slice into tiles. If the amount of data of a slice is less than the threshold, the dividing unit 4911 does not divide the slice into tiles.

[0361] For example, the dividing unit 4911 divides a slice into tiles so that the processing amount or processing time in the decoding device is within a certain range (a predetermined value or less). This makes the processing amount per tile in the decoding device constant, facilitating distributed processing in the decoding device.

[0362] Furthermore, when the processing amount differs between the position information and the attribute information, for example, when the processing amount of the position information is greater than the processing amount of the attribute information, the dividing unit 4911 divides the position information into a greater number of divisions than the attribute information.

[0363] Also, for example, depending on the content, if the decoding device may decode and display the position information quickly and decode and display the attribute information later slowly, the division unit 4911 may divide the position information into a larger number of parts than the attribute information. This allows the decoding device to process a larger number of pieces of position information in parallel, thereby making it possible to process the position information faster than the attribute information.

[0364] Note that the decoding device does not necessarily need to process sliced ​​or tiled data in parallel, and may determine whether to process them in parallel depending on the number or capabilities of the decoding processing units.

[0365] By dividing the data in the above manner, adaptive encoding according to the content or object can be realized. Also, parallel processing can be realized in the decoding process. This improves the flexibility of the point cloud encoding system or the point cloud decoding system.

[0366] Fig. 51 is a diagram showing examples of slice and tile division patterns. DU in the diagram is a data unit (DataUnit) and represents tile or slice data. Each DU includes a slice index (SliceIndex) and a tile index (TileIndex). The number in the upper right corner of the DU in the diagram indicates the slice index, and the number in the lower left corner of the DU indicates the tile index.

[0367] In pattern 1, the number of divisions and the division method are the same for G slices and A slices in slice division. In tile division, the number of divisions and the division method for G slices are different from the number of divisions and the division method for A slices. Furthermore, the same number of divisions and the division method are used among multiple G slices. The same number of divisions and the division method are used among multiple A slices.

[0368] In pattern 2, the number of divisions and the division method are the same for G slices and A slices in slice division. The number of divisions and the division method for G slices are different from the number of divisions and the division method for A slices in tile division. Furthermore, the number of divisions and the division method differ between multiple G slices. The number of divisions and the division method differ between multiple A slices.

[0369] Next, a method for encoding divided data will be described. A three-dimensional data encoding device (first encoding unit 4910) encodes each of the divided data. When encoding attribute information, the three-dimensional data encoding device generates dependency information as additional information, which indicates which configuration information (position information, additional information, or other attribute information) was used for encoding. In other words, the dependency information indicates, for example, the configuration information of the reference destination (dependency destination). In this case, the three-dimensional data encoding device generates dependency information based on configuration information corresponding to the division shape of the attribute information. Note that the three-dimensional data encoding device may generate dependency information based on configuration information corresponding to a plurality of division shapes.

[0370] The dependency information may be generated by the three-dimensional data encoding device, and the generated dependency information may be sent to the three-dimensional data decoding device. Alternatively, the three-dimensional data decoding device may generate the dependency information, and the three-dimensional data encoding device may not send the dependency information. Furthermore, the dependency relationships used by the three-dimensional data encoding device may be determined in advance, and the three-dimensional data encoding device may not send the dependency information.

[0371] Figure 52 is a diagram showing an example of the dependency relationships of each data. The tip of the arrow in the diagram indicates the dependency destination, and the start of the arrow indicates the dependency source. The three-dimensional data decoding device decodes data in the order from the dependency destination to the dependency source. Furthermore, data shown by solid lines in the diagram is data that is actually sent, and data shown by dotted lines is data that is not sent.

[0372] In the figure, G indicates location information, and A indicates attribute information. s1 indicates the position information of slice number 1, and G s2indicates the position information of slice number 2. G s1t1 indicates the position information of slice number 1 and tile number 1, and G s1t2 indicates the position information of slice number 1 and tile number 2, and G s2t1 indicates the position information of slice number 2 and tile number 1, and G s2t2 indicates the position information of slice number 2 and tile number 2. Similarly, A s1 indicates the attribute information of slice number 1, and A s2 indicates the attribute information of slice number 2. s1t1 indicates the attribute information of slice number 1 and tile number 1, and A s1t2 indicates the attribute information of slice number 1 and tile number 2, and A s2t1 indicates the attribute information of slice number 2 and tile number 1, and A s2t2 indicates attribute information of slice number 2 and tile number 2.

[0373] Mslice indicates slice additional information, MGtile indicates position tile additional information, and MAtile indicates attribute tile additional information. s1t1 is attribute information A s1t1 D s2t1 is attribute information A s2t1 This shows dependency information for

[0374] Furthermore, the three-dimensional data encoding device may rearrange the data in decoding order so that rearrangement of the data is not required in the three-dimensional data decoding device. Note that the data may be rearranged in the three-dimensional data decoding device, or the data may be rearranged in both the three-dimensional data encoding device and the three-dimensional data decoding device.

[0375] FIG. 53 is a diagram showing an example of the data decoding order. In the example of FIG. 53, decoding is performed in order from the left data. When data has a dependency relationship, the three-dimensional data decoding device decodes the dependent data first. For example, the three-dimensional data encoding device rearranges the data in advance to achieve this order before sending it. Note that any order is acceptable as long as the dependent data comes first. The three-dimensional data encoding device may also send the additional information and dependency information before the data.

[0376] Fig. 54 is a flowchart showing the flow of processing by the three-dimensional data encoding device. First, the three-dimensional data encoding device encodes data of multiple slices or tiles as described above (S4901). Next, the three-dimensional data encoding device rearranges the data so that the dependent data comes first, as shown in Fig. 53 (S4902). Next, the three-dimensional data encoding device multiplexes the rearranged data (into NAL units) (S4903).

[0377] Next, a description will be given of the configuration of the combining unit 4925 included in the first decoding unit 4920. Fig. 55 is a block diagram showing the configuration of the combining unit 4925. The combining unit 4925 includes a position information tile combining unit 4941 (geometry tile combiner), an attribute information tile combining unit 4942 (attribute tile combiner), and a slice combining unit (slice combiner).

[0378] The position information tile combining unit 4941 generates multiple slice position information pieces by combining multiple pieces of divided position information pieces using the position tile additional information. The attribute information tile combining unit 4942 generates multiple slice attribute information pieces by combining multiple pieces of divided attribute information pieces using the attribute tile additional information.

[0379] The slice combining unit 4943 generates position information by combining a plurality of slice position information pieces using the slice additional information. Also, the slice combining unit 4943 generates attribute information by combining a plurality of slice attribute information pieces using the slice additional information.

[0380] The number of slices or tiles to be divided is equal to or greater than 1. In other words, division into slices or tiles does not necessarily have to be performed.

[0381] Although an example in which tile division is performed after slice division has been shown here, slice division may be performed after tile division. Furthermore, new division types may be defined in addition to slices and tiles, and division may be performed using three or more division types.

[0382] Next, the structure of coded data divided into slices or tiles and a method of storing the coded data in NAL units (multiplexing method) will be described. Figure 56 is a diagram showing the structure of coded data and a method of storing the coded data in NAL units.

[0383] The coded data (segmentation position information and segmentation attribute information) is stored in the payload of the NAL unit.

[0384] The encoded data includes a header and a payload. The header includes identification information for identifying the data included in the payload. This identification information includes, for example, the type of slice division or tile division (slice_type, tile_type), index information for identifying a slice or tile (slice_idx, tile_idx), position information of the data (slice or tile), or the address of the data. The index information for identifying a slice is also referred to as a slice index (SliceIndex). The index information for identifying a tile is also referred to as a tile index (TileIndex). The type of division may be, for example, a method based on the object shape as described above, a method based on map information or position information, or a method based on the amount of data or processing amount.

[0385] Note that all or part of the above information may be stored in either the header of the division position information or the header of the division attribute information, but not in the other. For example, if the same division method is used for the position information and the attribute information, the division type (slice_type, tile_type) and index information (slice_idx, tile_idx) are the same for the position information and the attribute information. Therefore, this information may be included in the header of either the position information or the attribute information. For example, if the attribute information depends on the position information, the position information is processed first. Therefore, this information may be included in the header of the position information, but not in the header of the attribute information. In this case, the three-dimensional data decoding device determines, for example, that the dependent attribute information belongs to the same slice or tile as the slice or tile of the dependent position information.

[0386] Furthermore, additional information related to slice division or tile division (slice additional information, position tile additional information, or attribute tile additional information), and dependency information indicating dependency relationships may be stored in an existing parameter set (GPS, APS, position SPS, attribute SPS, etc.) and transmitted. If the division method changes for each frame, information indicating the division method may be stored in a parameter set for each frame (GPS or APS, etc.). If the division method does not change within a sequence, information indicating the division method may be stored in a parameter set for each sequence (position SPS or attribute SPS). Furthermore, if the same division method is used for position information and attribute information, information indicating the division method may be stored in a parameter set of the PCC stream (stream PS).

[0387] The above information may be stored in any one of the above parameter sets, or in multiple parameter sets. Alternatively, a parameter set for tile division or slice division may be defined, and the above information may be stored in the parameter set. Alternatively, the information may be stored in a header of the encoded data.

[0388] Furthermore, the header of the encoded data includes identification information indicating a dependency relationship. That is, when there is a dependency relationship between data, the header includes identification information for referencing the dependency from the dependency source. For example, the header of the dependency data includes identification information for identifying the data. The header of the dependency source data includes identification information indicating the dependency. Note that, when the identification information for identifying data, the additional information related to slice division or tile division, and the identification information indicating the dependency relationship can be identified or derived from other information, these pieces of information may be omitted.

[0389] Next, the flow of the encoding process and decoding process of point cloud data according to this embodiment will be described. Fig. 57 is a flowchart of the encoding process of point cloud data according to this embodiment.

[0390] First, the three-dimensional data encoding device determines the division method to be used (S4911). This division method includes whether or not to perform slice division and whether or not to perform tile division. The division method may also include the number of divisions when performing slice division or tile division, and the type of division. The type of division may be a method based on the object shape as described above, a method based on map information or position information, or a method based on the amount of data or the amount of processing. The division method may be determined in advance.

[0391] If slice division is performed (Yes in S4912), the three-dimensional data encoding device generates a plurality of slice position information and a plurality of slice attribute information by dividing the position information and the attribute information together (S4913). The three-dimensional data encoding device also generates slice additional information related to the slice division. Note that the three-dimensional data encoding device may divide the position information and the attribute information independently.

[0392] If tile division is performed (Yes in S4914), the three-dimensional data encoding device generates multiple pieces of division position information and multiple pieces of division attribute information by independently dividing multiple pieces of slice position information and multiple pieces of slice attribute information (or position information and attribute information) (S4915). The three-dimensional data encoding device also generates position tile additional information and attribute tile additional information related to the tile division. Note that the three-dimensional data encoding device may divide the slice position information and slice attribute information together.

[0393] Next, the three-dimensional data encoding device generates a plurality of pieces of encoding position information and a plurality of pieces of encoding attribute information by encoding each of the plurality of pieces of division position information and the plurality of pieces of division attribute information (S4916). The three-dimensional data encoding device also generates dependency relationship information.

[0394] Next, the three-dimensional data encoding device generates encoded data (encoded stream) by grouping (multiplexing) the plurality of pieces of encoding position information, the plurality of pieces of encoding attribute information, and the additional information into NAL units (S4917).The three-dimensional data encoding device also transmits the generated encoded data.

[0395] 58 is a flowchart of the decoding process of point cloud data according to this embodiment. First, the three-dimensional data decoding device determines the division method by analyzing additional information related to the division method (slice additional information, position tile additional information, and attribute tile additional information) included in the coded data (coded stream) (S4921). This division method includes whether or not to perform slice division and whether or not to perform tile division. The division method may also include the number of divisions when performing slice division or tile division, the type of division, etc.

[0396] Next, the three-dimensional data decoding device generates split position information and split attribute information by decoding the multiple pieces of coded position information and multiple pieces of coded attribute information contained in the coded data using the dependency information contained in the coded data (S4922).

[0397] If the additional information indicates that tile division has been performed (Yes in S4923), the three-dimensional data decoding device generates a plurality of slice position information and a plurality of slice attribute information by combining the plurality of pieces of division position information and the plurality of pieces of division attribute information using respective methods based on the position tile additional information and the attribute tile additional information (S4924). Note that the three-dimensional data decoding device may combine the plurality of pieces of division position information and the plurality of pieces of division attribute information using the same method.

[0398] When the additional information indicates that slice division has been performed (Yes in S4925), the three-dimensional data decoding device generates position information and attribute information by combining, based on the slice additional information, a plurality of pieces of slice position information and a plurality of pieces of slice attribute information (a plurality of pieces of division position information and a plurality of pieces of division attribute information) in the same manner (S4926). Note that the three-dimensional data decoding device may combine, using different methods, a plurality of pieces of slice position information and a plurality of pieces of slice attribute information.

[0399] As described above, the three-dimensional data encoding device according to this embodiment performs the processing shown in Fig. 60. First, the three-dimensional data encoding device divides a target space containing a plurality of three-dimensional points into a plurality of divided data (e.g., tiles) contained in a plurality of divided subspaces (e.g., slices), each containing one or more three-dimensional points (S4932). Here, the divided data is one or more data aggregates contained in a subspace and containing one or more three-dimensional points. The divided data may also be a space, and may include a space that does not contain three-dimensional points. Furthermore, one subspace may contain multiple divided data, or one subspace may contain one divided data. Note that multiple subspaces may be set in the target space, or one subspace may be set in the target space.

[0400] Next, the three-dimensional data encoding device generates a plurality of coded data corresponding to each of the plurality of divided data by encoding each of the plurality of divided data (S4931). The three-dimensional data encoding device generates a bitstream including the plurality of coded data and a plurality of control information (e.g., the header shown in FIG. 56) for each of the plurality of coded data (S4932). Each of the plurality of control information stores a first identifier (e.g., slice_idx) indicating a subspace corresponding to the coded data corresponding to the control information, and a second identifier (e.g., tile_idx) indicating divided data corresponding to the coded data corresponding to the control information.

[0401] This allows a three-dimensional data decoding device that decodes a bitstream generated by a three-dimensional data encoding device to easily restore the target space by combining data from the plurality of divided data using the first identifier and the second identifier, thereby reducing the amount of processing required in the three-dimensional data decoding device.

[0402] For example, the three-dimensional data encoding device encodes position information and attribute information of three-dimensional points included in each of the plurality of pieces of divided data. Each of the plurality of pieces of coded data includes coded data for the position information and coded data for the attribute information. Each of the plurality of pieces of control information includes control information for the coded data for the position information and control information for the coded data for the attribute information. The first identifier and the second identifier are stored in the control information for the coded data for the position information.

[0403] For example, in a bitstream, each of the plurality of pieces of control information is placed before the coded data corresponding to that control information.

[0404] Furthermore, a three-dimensional data encoding device may be configured such that a target space containing a plurality of three-dimensional points is set to one or more subspaces, the subspaces contain one or more divided data each containing one or more three-dimensional points, and the device generates a plurality of coded data corresponding to each of the plurality of divided data by encoding each of the divided data, and generates a bit stream including the plurality of coded data and a plurality of control information for each of the plurality of coded data, and each of the plurality of control information stores a first identifier indicating the subspace corresponding to the coded data corresponding to the control information, and a second identifier indicating the divided data corresponding to the coded data corresponding to the control information.

[0405] For example, the three-dimensional data encoding device includes a processor and a memory, and the processor performs the above-mentioned processing using the memory.

[0406] Moreover, the three-dimensional data decoding device according to this embodiment performs the processing shown in FIG. 60. First, the three-dimensional data decoding device acquires, from a bitstream including a plurality of coded data pieces generated by encoding a plurality of divided data pieces (e.g., tiles) each including one or more three-dimensional points and included in a plurality of subspaces (e.g., slices) obtained by dividing a target space including a plurality of three-dimensional points, and a plurality of control information pieces (e.g., a header shown in FIG. 56) for each of the plurality of coded data pieces, a first identifier (e.g., slice_idx) indicating a subspace corresponding to the coded data piece corresponding to the control information piece, and a second identifier (e.g., tile_idx) indicating divided data piece corresponding to the coded data piece corresponding to the control information piece, both of which are stored in the plurality of control information pieces (S4941). Next, the three-dimensional data decoding device restores a plurality of divided data pieces by decoding the plurality of coded data pieces (S4942). Next, the three-dimensional data decoding device restores the target space by combining the plurality of divided data pieces using the first identifier and the second identifier (S4943). For example, the three-dimensional data encoding device uses the second identifier to combine multiple divided data to restore multiple subspaces, and uses the first identifier to combine multiple subspaces to restore the target space (multiple three-dimensional points). Note that the three-dimensional data decoding device may use at least one of the first identifier and the second identifier to obtain coded data of a desired subspace or divided data from the bitstream, and selectively decode or preferentially decode the obtained coded data.

[0407] This allows the three-dimensional data decoding device to easily restore the target space by combining the data of the plurality of divided data using the first identifier and the second identifier, thereby reducing the amount of processing in the three-dimensional data decoding device.

[0408] For example, each of the plurality of coded data is generated by encoding position information and attribute information of a three-dimensional point included in the corresponding divided data, and includes coded data of the position information and coded data of the attribute information. Each of the plurality of control information includes control information for the coded data of the position information and control information for the coded data of the attribute information. The first identifier and the second identifier are stored in the control information of the coded data of the position information.

[0409] For example, in the bitstream, control information precedes the corresponding coded data.

[0410] For example, the three-dimensional data decoding device includes a processor and a memory, and the processor performs the above processing using the memory.

[0411] Although the three-dimensional data encoding device and the three-dimensional data decoding device according to the embodiments of the present disclosure have been described above, the present disclosure is not limited to these embodiments.

[0412] Furthermore, each processing unit included in the three-dimensional data encoding device and three-dimensional data decoding device according to the above embodiments is typically realized as an LSI, which is an integrated circuit. These may be individually implemented as single chips, or some or all of them may be integrated into a single chip.

[0413] Furthermore, the integration is not limited to LSI, but may be realized by dedicated circuits or general-purpose processors. FPGAs (Field Programmable Gate Arrays), which can be programmed after LSI fabrication, or reconfigurable processors, which allow the connections and settings of circuit cells within LSIs to be reconfigured, may also be used.

[0414] In each of the above embodiments, each component may be configured with dedicated hardware, or may be realized by executing a software program suitable for each component. Each component may be realized by a program execution unit such as a CPU or processor reading and executing a software program recorded on a recording medium such as a hard disk or semiconductor memory.

[0415] Furthermore, the present disclosure may be realized as a three-dimensional data encoding method or a three-dimensional data decoding method executed by a three-dimensional data encoding device, a three-dimensional data decoding device, or the like.

[0416] The division of functional blocks in the block diagram is an example, and multiple functional blocks may be realized as a single functional block, one functional block may be divided into multiple blocks, or some functions may be moved to another functional block.Furthermore, the functions of multiple functional blocks having similar functions may be processed in parallel or in time-sharing by a single piece of hardware or software.

[0417] The order in which the steps in the flowchart are executed is merely an example for specifically explaining the present disclosure, and other orders may be used. Some of the steps may be executed simultaneously (in parallel) with other steps.

[0418] While the three-dimensional data encoding device and three-dimensional data decoding device according to one or more aspects have been described above based on the embodiments, the present disclosure is not limited to these embodiments. As long as they do not deviate from the spirit of the present disclosure, various modifications conceivable by those skilled in the art to the present embodiments, and configurations constructed by combining components of different embodiments, may also be included within the scope of one or more aspects. [Industrial Applicability]

[0419] The present disclosure is applicable to a three-dimensional data encoding device and a three-dimensional data decoding device. [Explanation of symbols]

[0420] 4601 Three-dimensional data encoding system 4602 Three-dimensional data decoding system 4603 Sensor Terminal 4604 External connection part 4611 Point Cloud Data Generation System 4612 Presentation section 4613 Encoding section 4614 Multiplexer 4615 Input / output section 4616 Control Unit 4617 Sensor information acquisition unit 4618 Point Cloud Data Generation Unit 4621 Sensor Information Acquisition Unit 4622 Input / output section 4623 Demultiplexer 4624 Decoding Unit 4625 Presentation section 4626 User Interface 4627 Control Unit 4630 First Encoding Section 4631 Location information encoder 4632 Attribute information encoder 4633 Additional information coding unit 4634 Multiplexer 4640 First Decoding Unit 4641 Demultiplexer 4642 Location Information Decoding Unit 4643 Attribute Information Decoding Unit 4644 Additional information decoding unit 4650 Second Encoding Section 4651 Additional Information Generation Unit 4652 Position image generation unit 4653 Attribute Image Generation Unit 4654 Video Encoding Unit 4655 Additional information coding unit 4656 Multiplexer 4660 Second Decoding Unit 4661 Demultiplexer 4662 Video Decoding Unit 4663 Additional Information Decoding Unit 4664 Location information generator 4665 Attribute information generation section 4670 Encoding section 4671 Multiplexer 4680 Decoding Unit 4681 Demultiplexer 4710 First Multiplexing Unit 4711 File Conversion Unit 4720 First Demultiplexer 4721 File Reverse Conversion Unit 4730 Second Multiplexing Unit 4731 File Conversion Unit 4740 Second Demultiplexer 4741 File Reverse Conversion Unit 4750 Third Multiplexer 4751 File Conversion Unit 4760 Third Demultiplexer 4761 File Reverse Conversion Unit 4801 Encoding section 4802 Multiplexer 4910 First Encoding Section 4911 Split section 4912 Location information encoder 4913 Attribute information encoder 4914 Additional information coding unit 4915 Multiplexer 4920 First Decoding Unit 4921 Demultiplexer 4922 Location Information Decoding Unit 4923 Attribute Information Decoding Unit 4924 Additional information decoding unit 4925 Joint 4931 Slice division part 4932 Location information tile division part 4933 Attribute information tile division part 4941 Location information tile joint 4942 Attribute information tile combination 4943 Slice Junction

Claims

1. generating a bitstream including a plurality of coded data pieces in which data corresponding to different three-dimensional spaces are coded, and a plurality of pieces of control information for each of the plurality of coded data pieces; Each of the plurality of pieces of control information stores a first identifier indicating a space corresponding to the coded data corresponding to the control information, and a second identifier indicating data corresponding to the coded data corresponding to the control information. Three-dimensional data generation method.

2. Each of the plurality of coded data includes coded data of position information and coded data of attribute information. The three-dimensional data generating method according to claim 1.

3. In the bitstream, the first identifier and the second identifier are placed before the corresponding encoded data.

3. The three-dimensional data generating method according to claim 1 or 2.

4. The three-dimensional space includes one or more three-dimensional points. The three-dimensional data generating method according to claim 1.

5. acquiring, from the bitstream, a plurality of coded data pieces in which data corresponding to different three-dimensional spaces are coded, and a plurality of pieces of control information for each of the plurality of coded data pieces; A first identifier indicating a space corresponding to the coded data corresponding to the control information and a second identifier indicating data corresponding to the coded data corresponding to the control information are obtained. Three-dimensional data processing methods.

6. Each of the plurality of coded data includes coded data of position information and coded data of attribute information.

6. The three-dimensional data processing method according to claim 5.

7. In the bitstream, the first identifier and the second identifier are placed before the corresponding encoded data.

7. The three-dimensional data processing method according to claim 5 or 6.

8. The three-dimensional space includes one or more three-dimensional points.

6. The three-dimensional data processing method according to claim 5.

9. a processor; a memory; The processor uses the memory to: generating a bitstream including a plurality of coded data pieces in which data corresponding to different three-dimensional spaces are coded, and a plurality of pieces of control information for each of the plurality of coded data pieces; Each of the plurality of pieces of control information stores a first identifier indicating a space corresponding to the coded data corresponding to the control information, and a second identifier indicating data corresponding to the coded data corresponding to the control information. Three-dimensional data generation device.

10. a processor; a memory; The processor uses the memory to: acquiring, from the bitstream, a plurality of coded data pieces in which data corresponding to different three-dimensional spaces are coded, and a plurality of pieces of control information for each of the plurality of coded data pieces; A first identifier indicating a space corresponding to the coded data corresponding to the control information and a second identifier indicating data corresponding to the coded data corresponding to the control information are obtained. Three-dimensional data processing device.

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