Image coding method, encoder, decoder, and storage medium

Abstract

The embodiment of the application discloses an image coding method, an encoder, a decoder and a storage medium. Before encoding processing according to a MIP mode, the encoder uniformly modifies initial right shift parameters corresponding to different sizes and different MIP mode numbers according to an offset parameter; wherein the offset parameter is used for indicating the right shift number of a prediction value; and when encoding processing according to the MIP mode, the encoding processing is performed according to the offset parameter. Before decoding processing according to the MIP mode, the decoder uniformly modifies initial right shift parameters corresponding to different sizes and different MIP mode numbers according to an offset parameter; wherein the offset parameter is used for indicating the right shift number of a prediction value; and when decoding processing according to the MIP mode, the decoding processing is performed according to the offset parameter.

Description

[0001] This application is a divisional application of PCT International Patent Application No. PCT / CN2019 / 092689, filed on June 25, 2019, entitled "Image Coding Method, Encoder, Decoder and Storage Medium", which entered the Chinese national phase as Chinese Patent Application No. 201980048358.2. TECHNICAL FIELD

[0002] Embodiments of the present application relate to the technical field of video coding, in particular to an image coding method, an encoder, a decoder and a storage medium. BACKGROUND

[0003] In the reference software test platform of Versatile Video Coding (VVC), a new intra coding technology, Matrix-based Intra Prediction (MIP), is proposed. MIP is a neural network-based intra prediction technology, that is, a multi-layer neural network is used to predict the luminance value of the current block based on the adjacent reconstructed luminance blocks. Specifically, the input of MIP prediction is also the data of the adjacent luminance blocks of the previous row and the left column of the current block when intra prediction is performed using the MIP mode, and the output is the predicted value of the luminance component of the current block. The specific prediction process includes three steps: downsampling, matrix-vector multiplication and interpolation.

[0004] However, when predicting the luminance value by using the MIP mode, the parameters used by the luminance blocks of different sizes may also be different. Therefore, a large storage space is required to store a large number of parameters, and the searching and calling of the parameters in the prediction process also increases the overall time, thereby reducing the coding efficiency. SUMMARY

[0005] Embodiments of the present application provide an image coding method, an encoder, a decoder and a storage medium, which can reduce the storage space and the overall time required in the coding process while ensuring the coding performance, thereby effectively improving the coding efficiency.

[0006] The technical solutions of the embodiments of the present application are as follows:

[0007] The present application provides an image coding method applied to an encoder, the method comprising:

[0008] Before coding processing according to the MIP mode, the initial right shift parameters corresponding to different sizes and different MIP mode numbers are uniformly modified according to the offset parameter; wherein the offset parameter is used to indicate the right shift number of the predicted value; and

[0009] In the encoding process according to the MIP mode, the encoding process is performed according to the offset parameter.

[0010] Embodiments of the present application provide an image decoding method, applied to a decoder, the method comprising:

[0011] Before the decoding process according to the MIP mode, the initial right shift parameters corresponding to different sizes and different MIP mode numbers are uniformly modified according to an offset parameter; wherein the offset parameter is used to indicate the right shift number of the prediction value; and

[0012] In the decoding process according to the MIP mode, the decoding process is performed according to the offset parameter.

[0013] Embodiments of the present application provide an encoder, comprising a first modification part and an encoding part,

[0014] The first modification part is configured to uniformly modify the initial right shift parameters corresponding to different sizes and different MIP mode numbers according to an offset parameter before the encoding process according to the MIP mode; wherein the offset parameter is used to indicate the right shift number of the prediction value.

[0015] The encoding part is configured to perform the encoding process according to the offset parameter when the encoding process according to the MIP mode is performed.

[0016] Embodiments of the present application provide a decoder, comprising a second modification part and a decoding part,

[0017] The second modification part is configured to uniformly modify the initial right shift parameters corresponding to different sizes and different MIP mode numbers according to an offset parameter before the decoding process according to the MIP mode; wherein the offset parameter is used to indicate the right shift number of the prediction value.

[0018] The decoding part is configured to perform the decoding process according to the offset parameter when the decoding process according to the MIP mode is performed.

[0019] Embodiments of the present application provide an encoder, comprising a first processor, a first memory storing instructions executable by the first processor, a first communication interface, and a first bus for connecting the first processor, the first memory, and the first communication interface, when the instructions are executed by the first processor, the image encoding method as described above is implemented.

[0020] The embodiment of the present application provides a decoder, which comprises a second processor, a second memory storing executable instructions of the second processor, a second communication interface, and a second bus for connecting the second processor, the second memory and the first communication interface, and when the instructions are executed by the second processor, the image decoding method as described above is realized.

[0021] The embodiment of the present application provides a computer readable storage medium, which stores a program, and is applied to an encoder and a decoder, and when the program is executed by a processor, the image coding method as described above is realized.

[0022] The embodiment of the present application provides an image coding method, an encoder, a decoder and a storage medium, wherein the encoder modifies the initial right shift parameters corresponding to different sizes and different MIP mode numbers uniformly according to an offset parameter before encoding processing according to the MIP mode; wherein the offset parameter is used for indicating the right shift number of the prediction value; and the encoding processing is performed according to the offset parameter when the encoding processing is performed according to the MIP mode. The decoder modifies the initial right shift parameters corresponding to different sizes and different MIP mode numbers uniformly according to an offset parameter before decoding processing according to the MIP mode; and the decoding processing is performed according to the offset parameter when the decoding processing is performed according to the MIP mode. Therefore, the image coding method provided by the present application modifies the right shift number of the prediction value uniformly by using the offset parameter, so that all the luma blocks with different sizes and different MIP mode numbers have the same sW value, thereby when the coding processing is performed, the sW value does not need to be queried and called, the complexity of the MIP algorithm can be reduced, the storage space and the overall time required in the coding process can be reduced on the basis of ensuring the coding performance, and the coding efficiency is effectively improved. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 It is an arrangement diagram of 67 prediction modes in the intra prediction;

[0024] Figure 2 It is a flowchart of encoding the MIP mode;

[0025] Figure 3 It is an arrangement diagram of the upper adjacent luma block and the left adjacent luma block of the current block;

[0026] Figure 4 It is an arrangement diagram of determining the DM mode;

[0027] Figure 5 It is a structural diagram of the video coding system;

[0028] Figure 6This is a schematic diagram of the structure of a video decoding system;

[0029] Figure 7 This is a schematic diagram of the implementation process of an image encoding method proposed in an embodiment of this application. Figure 1 ;

[0030] Figure 8 This is a schematic diagram of the implementation process of an image encoding method proposed in an embodiment of this application. Figure 2 ;

[0031] Figure 9 This is a schematic diagram of the implementation process of an image decoding method proposed in an embodiment of this application. Figure 1 ;

[0032] Figure 10 This is a schematic diagram of the implementation process of an image decoding method proposed in an embodiment of this application. Figure 2 ;

[0033] Figure 11 This is a schematic diagram of the encoder structure proposed in the embodiments of this application. Figure 1 ;

[0034] Figure 12 This is a schematic diagram of the encoder structure proposed in the embodiments of this application. Figure 2 ;

[0035] Figure 13 A schematic diagram of the decoder structure proposed in the embodiments of this application. Figure 1 ;

[0036] Figure 14 A schematic diagram of the decoder structure proposed in the embodiments of this application. Figure 2 . Detailed Implementation

[0037] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. It is understood that the specific embodiments described herein are merely for explaining the relevant application and not for limiting the application. Furthermore, it should be noted that, for ease of description, only the parts relevant to the application are shown in the accompanying drawings.

[0038] In video images, VVC adopted the Affine Linear Weighted IntraPrediction technique proposed by the Joint Video Experts Team (JVET)-N0217 and renamed it Matrix-based IntraPrediction, or MIP. This technique adds different numbers of matrix-based intraprediction modes to the intraluminance prediction process depending on the size of the intraluminance coding block.

[0039] To capture finer edge directions presented in natural videos, the 33 intra luma prediction angular modes defined in the video compression standard (High Efficiency Video Coding, HEVC) are extended to 65 in VVC, Figure 1 The arrangement of the 67 prediction modes in intra prediction is shown in FIG. 1, where the arrow numbers 2-66 represent the 65 intra angular prediction modes, and the other two non-angular modes are the Planar mode with number 0 and the DC mode with number 1; therefore, the intra prediction process in VVC contains two non-angular modes and 65 angular modes, which are referred to as the traditional modes of intra prediction. Figure 1

[0040] MIP is a neural network-based intra prediction technique, i.e., a multi-layer neural network is used to predict the luma value of the current block based on the neighboring reconstructed pixels. Specifically, the MIP technique divides the luma coding block into three categories according to the size of the intra luma coding block, assuming that the size of the luma coding block is WxH, where W is the width parameter and H is the height parameter. According to the size of the luma coding block, the luma coding block can be divided into three categories:

[0041] The luma coding block with a size of 4x4 is the first type of luma block, the luma coding block with a size of 8x4, 4x8 and 8x8 is the second type of luma block, and the luma coding block with other sizes is the third type of luma block.

[0042] For the three types of intra luma coding blocks, the MIP technique increases M MIP modes based on the 67 traditional intra prediction modes, where M=35 for the first type of luma block, M=19 for the second type of luma block, and M=11 for the third type of luma block.

[0043] Specifically, the MIP technique is only applied to intra luma prediction, and the input of MIP prediction is also the upper row and left column data of the current block, and the output is the prediction value of the current block. The specific prediction process includes three steps: averaging, matrix-vector multiplication and interpolation. That is, by performing these three operations on the reconstructed luma values of the input adjacent pixels in the upper row and left column, the luma component prediction value of the current block can be obtained.

[0044] Figure 2 The flowchart for encoding the MIP mode is shown in FIG. 2, and the specific implementation of the luma prediction of the MIP mode is as follows: Figure 2

[0045] Step 1: Perform averaging operation on the upper adjacent reference points of the current block to obtain vector bdry top ​​, a total of N values; the average operation is performed on the left neighboring reference points of the current block to obtain a vector bdry left , a total of N values. When the current block is the first type of luma coding, N = 2; when the current block is the second type or the third type of luma coding, N = 4. The vector bdry top and the vector bdry left constitute a new vector bdry red and subsequent operations are performed;

[0046] Second step: obtain the corresponding matrix A k and offset b k through the mode number k of the MIP mode, as shown in the following formula (1): Figure 2 The partial prediction value of the current block marked by the cross line in the formula (1) is obtained:

[0047] Pred red = A k ·bdry red +b k (1)

[0048] Third step: obtain the remaining prediction value Predred in the current block through linear interpolation.

[0049] It should be noted that, in the implementation process of encoding the current block, it is necessary to write which encoding mode of the specific intra prediction into the compressed code stream, so that the decoding end can determine which mode to use by analyzing the mode information, that is, whether to use the traditional mode or the MIP mode; if it is the traditional mode, which traditional mode; if it is the MIP mode, which MIP mode.

[0050] In the intra prediction of VVC, the rate distortion cost RDcost of 67 traditional modes and M MIP modes is compared for each luma coding block, and the optimal mode is selected from the 67 traditional modes and M MIP modes and is coded. In order to save bit overhead, the intra mode coding technology based on the most probable mode list (MPM) is used in VVC.

[0051] It should be noted that, since the multi-reference line technology (extend reference line) and the intra sub-block partition technology (ISP) are only used for the modes in the MPM list, when the extendrefflag and the ispflag are both 0, that is, the 0 reference line is used and the sub-block partition is not performed, the mpmflag does not need to be coded, and the position of the optimal mode in the MPM list is directly coded.

[0052] Further, for the construction of MPM list and MIP MPM list, in VVC luma intra prediction, if the optimal mode of the current block is a traditional mode, a MPM list containing 6 most probable traditional modes needs to be constructed; if the optimal mode of the current block is a MIP mode, a MIP MPM list containing 3 most probable MIP modes needs to be constructed.

[0053] Figure 3 For the arrangement of the top neighboring luma block and the left neighboring luma block of the current block, as shown in FIG. 1, the above two lists are derived according to the optimal modes of the top neighboring luma block (A) and the left neighboring luma block (L) of the current block as shown in FIG. 2. Figure 3 Figure 3

[0054] Further, for the construction of MIP MPM list, in VVC intra prediction, if the optimal mode of the current block is a MIP mode, a MIP MPM list needs to be constructed. In the process of constructing the MIP MPM list, first, the MIP mode corresponding to the optimal mode of the top neighboring luma block, i.e. ABOVE MIP, and the MIP mode corresponding to the optimal mode of the left neighboring luma block, i.e. LEFT MIP, need to be obtained.

[0055] Further, after obtaining LEFT MIP and ABOVE MIP, the MIP MPM list containing 3 most probable MIP MPM modes is constructed according to the following method, wherein the number in MIP MPM is the number of MIP mode, the number range is 0 to (M-1), for the first type of luma block, the number is 0-34; for the second type of luma block, the number is 0-18; for the third type of luma block, the number is 0-10:

[0056] If LEFT MIP is available (not -1), LEFT MIP is put into MIP MPM list;

[0057] If ABOVE MIP is available (not -1), ABOVE MIP is put into MIP MPM list after redundancy check;

[0058] If LEFT MIP is not available (is -1), ABOVE MIP is not available (is -1), according to the type of the current block, the default list is added to fill the MIP MPM list after redundancy check:

[0059] The default list of the first type of luma block is: {17, 34, 5};

[0060] The default list of the second type of luma block is: {0, 7, 16};

[0061] The default list of the third type of luma block is: {1, 4, 6}.​​

[0062] Furthermore, it should be added that in the intra-chroma prediction process of VVC, there is a Direct Mode (DM) that utilizes inter-component correlation. This mode uses the intra-prediction mode based on the center position of the corresponding luma coding block to perform intra-prediction of the current chroma block. Figure 4 To determine the layout diagram of the DM pattern, as follows: Figure 4 As shown, since MIP technology is only applied to luma-coded blocks, when Figure 4 When the intra-prediction mode at the CR position is MIP mode, the MIP mode needs to be mapped to traditional mode through the "MIP-Traditional Mapping Table" to perform intra-prediction of the current chroma block.

[0063] In other words, due to the introduction of MIP technology, during the intra-frame prediction process, in constructing the MIPMPM list, it is necessary to map the traditional mode to the MIP mode, and in constructing the MPM list and determining the DM mode, it is necessary to map the MIP mode to the traditional mode.

[0064] Table 1

[0065]

[0066] In addition, the MPM list construction process and DM mode acquisition process require the use of MIP mode to traditional mode mapping. Specifically, the "MIP-Traditional Mapping Table" maps 35 / 19 / 11 MIP modes to 67 traditional modes. For the three types of luma blocks, the three "MIP-Traditional Mapping Tables" are shown in Tables 2, 3 and 4.

[0067] Table 2

[0068]

[0069]

[0070] Table 3

[0071] MIP mode 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 Legacy mode 0 1 0 1 0 22 18 18 1 0 1 0 1 0 44 0 50 1 0

[0072] Table 4

[0073] MIP mode 0 1 2 3 4 5 6 7 8 9 10 Legacy mode 1 1 1 1 18 0 1 0 1 50 0

[0074] Figure 5 This is a schematic diagram of the structure of a video encoding system, such as... Figure 5As shown, the video coding system 100 includes a transform and quantization module 101, an intra-frame estimation module 102, an intra-frame prediction module 103, a motion compensation module 104, a motion estimation module 105, an inverse transform and inverse quantization module 106, a filter control and analysis module 107, a deblocking filtering and sample adaptive offset (SAO) filtering module 108, a header information encoding and context-based adaptive binary arithmetic coding (CABAC) encoding module 109, and a decoding image buffer module 110, etc. Figure 6 This is a schematic diagram of the structure of a video decoding system, such as... Figure 6 As shown, the video decoding system 200 includes components such as a header information decoding and CABAC decoding module 201, an inverse transform and inverse quantization module 202, an intra-frame prediction module 203, a motion compensation module 204, a deblocking and SAO filtering module 205, and a decoded image buffer module 206. After the video image is processed by the transform and quantization module 101, the intra-frame estimation module 102, the intra-frame prediction module 103, the motion compensation module 104, the motion estimation module 105, the deblocking and SAO filtering module 108, and the header information encoding and CABAC module 109 in the video encoding system 100, the bitstream of the video image is output. This bitstream is input into the video decoding system 200, and after being processed by the header information decoding and CABAC decoding module 201, the inverse transform and inverse quantization module 202, the intra-frame prediction module 203, and the motion compensation module 204 in the video decoding system 200, the original video image is finally recovered.

[0075] Based on the height and width parameters, the current block can have 25 sizes. Specifically, the standard specifies that the maximum size of the luminance block is 128×128. However, since the maximum size of the transformation unit is 64×64, a luminance block of 128×128 size must first undergo quadtree partitioning. Therefore, the maximum luminance block size is 64×64. Table 5 shows a schematic diagram of the luminance block sizes.

[0076] Table 5

[0077]

[0078]

[0079] In the prior art, the MIP mode is restricted based on the height and width parameters of the current block. Specifically, if the aspect ratio of the current block is greater than 4, or the height-to-width ratio is greater than 4, then the current block is not encoded using the MIP mode. Table 6 shows the restrictions on the luma block size in the prior art under the MIP mode.

[0080] Table 6

[0081]

[0082] In the prior art, in the first type of luma block in MIP mode (corresponding to 4x4 luma block), each of the two upper and left neighboring luma blocks generates a 4x4 prediction block through matrix operation; in the second type of luma block in MIP mode (corresponding to 4x8, 8x4, 8x8 luma block), each of the four upper and left neighboring luma blocks generates a 4x4 prediction block through matrix operation; in the third type of luma block in MIP mode (corresponding to luma block of other sizes), each of the four upper and left neighboring luma blocks generates a 4x8 prediction block (4x16 luma block), an 8x4 prediction block (16x4 luma block) or an 8x8 prediction block (luma block of other sizes) through matrix operation. Among them, since the third type of luma block generates a non-square prediction block, odd rows of the matrix need to be extracted when calculating.

[0083] Further, in the syntax, MipSizeId can be used to represent the application category of MIP, numModes represents the number of MIP modes, boundarySize represents the number of luma blocks of the upper reference row or the left reference column obtained by downsampling, predW represents the width parameter of the prediction block, predH represents the height parameter of the prediction block, and predC represents the side length of the MIP matrix. Table 7 is the syntax relationship corresponding to the MIP mode in the prior art. As shown in Table 7, MipSizeId, numModes, boundarySize, predW, predH and predC in the syntax have the following relationships:

[0084] Table 7

[0085] MipSizeId numModes boundarySize predW predH predC 0 35 2 4 4 4 1 19 4 4 4 4 2 11 4 Min(nTbW, 8) Min(nTbH, 8) 8

[0086] Further, in the syntax, MipSizeId takes a value of 0 to represent a 4x4 luma block, a value of 1 to represent a 4x8, 8x4, 8x8 luma block, and a value of 2 to represent a luma block of other sizes. numModes represents the total number of MIP prediction modes, i.e., 35 for a 4x4 luma block, 19 for a 4x8, 8x4, 8x8 luma block, and 11 for a luma block of other sizes. boundarySize represents the adjacent luma blocks of the upper row or the left column of the current block which are finally downsampled into 2 or 4 adjacent luma blocks.

[0087] In the prior art, when the encoder performs luma prediction through the MIP mode, the following formula (2) can be used:

[0088]

[0089] wherein mWeight and vBias are the weight matrix and bias matrix of each MIP mode trained by deep learning, specifically, mWeight is the weight matrix of each type of MIP mode, and vBias is the bias matrix of each type of MIP mode. sB is the left shift amount of the bias matrix, oW is the rounding reserved value, sW is the right shift amount of the overall prediction value, and sW values under different MIP modes need to be obtained by looking up the table.

[0090] Based on JVET-N1001-v7, when generating the prediction matrix of MIP, the encoder judges whether the prediction value of the odd row needs to be extracted through variables incW and incH, specifically:

[0091] oW = 1 << (sW - 1)

[0092] sB = BitDepth Y -1

[0093] mipW = isTransposed? predH : predW

[0094] mipH = isTransposed? predW : predH

[0095] incW = (predC > mipW)? 2 : 1

[0096] incH = (predC > mipH)? 2 : 1

[0097] Wherein, incW = 2 or incH = 2 represents that extraction needs to be performed on the width parameter or the height parameter.

[0098] Table 8 is the syntax description of sW in the prior art, as shown in Table 8, when and only when MipSizeId is equal to 1, that is, the current block size is 4x8, 8x4, 8x8, and the MIP mode number is 3, 8, 12, and 17, sW takes the value of 9, and the sW value under all other MIP modes is 8. Wherein, since the sW value under the MIP mode is a mapping relationship, the sW value under all modes can be obtained through Table 8.

[0099] Table 8

[0100]

[0101] Table 9 is the mWeight matrix when MipSizeId is 1, the MIP mode number is 3 and 12.

[0102] Table 9

[0103] 218 -56 9 -3 411 -76 12 -4 448 94 -45 6 23 -15 2 -3 -1 476 77 -34 -5 -2 1 -3 1 -16 466 61 5 -4 1 -3 -38 2 -3 0 260 358 -77 8 122 -39 1 -1 463 -25 -11 -2 405 54 -41 5 121 -33 2 -6 107 402 16 -12 3 -4 1 -6 5 -1 -1 0 -62 267 375 -73 -25 3 -4 -1 108 466 -28 -11 58 -25 -3 -1 418 96 -35 -3 301 18 -15 5 229 -21 -4 -7 -1 -3 -2 -2 24 -95 291 297 3 1 -5 -2 -30 103 464 -29 -16 0 -6 0 41 429 70 -13 27 -5 -2 1 303 193 -13 -1

[0104] Table 10 is the vBias matrix when MipSizeId is 1, MIP mode number is 3 and 12.

[0105] Table 10

[0106] 1 2 3 1 1 3 3 3 2 4 4 4 3 5 5 5

[0107] Table 11 is the mWeight matrix when MipSizeId is 1, MIP mode number is 8 and 17. Table 12 is the vBias matrix when MipSizeId is 1, MIP mode number is 8 and 17.

[0108] Table 11

[0109] -91 23 13 8 209 261 72 24 -26 -22 14 13 88 306 114 35 -16 18 -16 5 31 327 135 39 -11 11 30 -19 3 325 142 41 12 -4 1 1 -14 273 227 26 3 10 -3 -5 6 231 249 34 1 8 5 -9 10 214 262 37 -1 11 4 -7 15 208 259 40 5 0 4 -4 6 92 340 78 4 6 1 -5 6 113 329 75 2 13 2 -8 6 123 319 75 1 13 6 -10 9 136 303 74 6 1 4 -5 8 38 217 252 4 10 1 -7 9 58 313 141 3 12 4 -8 11 70 327 114 2 14 4 -7 14 82 314 110

[0110] Table 12

[0111] -7 -10 -11 -11 -10 -14 -17 -18 -11 -15 -19 -21 -10 -17 -21 -22

[0112] Due to the different syntax descriptions of sW in different MIP modes as shown in Table 8, when the encoder performs luminance prediction through the MIP mode, if the MipSizeId of the current block is 1, that is, the current block is a second type of luminance block (a luminance block with a size of 4x8, 8x4 or 8x8), and the MIP mode number corresponding to the current coding block is 3, 8, 12 or 17, the value of sW will be different from that in other modes, which causes the algorithm to be inconsistent, and the process of querying the above table 8 increases the time complexity of the algorithm, and the storage of table 8 also needs to occupy storage space. That is, when performing luminance prediction through the MIP mode, the parameters used by luminance blocks of different sizes may also be different, so a large storage space is needed to store a large number of parameters, and the searching and calling of parameters in the prediction process also increases the overall time, thereby reducing the coding efficiency.

[0113] To solve the above problems, the present application provides an image coding method, by modifying the value of sW when the second type of luminance block is in the MIP mode number of 3, 8, 12 and 17, so that the value of sW in all MIP mode numbers is the same, thereby reducing the storage space and reducing the overall time by omitting the table lookup operation.

[0114] Further, the image coding method provided by the present application can affect the intra prediction part in the video coding hybrid framework, that is, mainly applied to the intra prediction module 103 in the video coding and the intra prediction module 203 in the video decoding, which simultaneously acts on the encoding end and the decoding end.

[0115] It should be noted that in the embodiments of the present application, based on the calculation parameters trained by the machine learning method, the image coding method proposed in the present application can uniformly modify sW according to the fixed offset parameter, and simultaneously modify the corresponding weight matrix and bias matrix. In the present application, the modification of the value of sW when the MIP mode number of the second type of luminance block is 3, 8, 12, and 17 is not limited, but the different values of sW are uniformly modified after the specific parameters (including different combinations of size, mode, right shift value, etc.) are changed.

[0116] Further, in the following embodiments, the value of sW when the MIP mode number of the second type of luminance block is 3, 8, 12, and 17 is taken as an example to illustrate the image coding method proposed in the present application.

[0117] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application.

[0118] In an embodiment of the present application, Figure 7 An implementation process of an image coding method proposed in an embodiment of the present application is shown in the following. Figure 1 As shown in the following, Figure 7 In the embodiments of the present application, the method of the encoder for image coding can include the following steps.

[0119] Step 101, before encoding processing according to the MIP mode, uniformly modifying the initial right shift parameters corresponding to different sizes and different MIP mode numbers according to the offset parameter; wherein the offset parameter is used to indicate the right shift number of the prediction value.

[0120] In the embodiments of the present application, before encoding processing according to the MIP mode, the encoder can first set the offset parameter used to indicate the offset number.

[0121] It should be noted that in the embodiments of the present application, based on the above formula (2), the offset parameter is sW in formula (2), that is, the offset parameter is the right shift number of the overall prediction value. That is, when predicting the luminance of the current block, the offset parameter is used to indicate the right shift number of the overall prediction value of the current block.

[0122] Further, in the embodiments of the present application, the encoder can set the offset parameter to a fixed positive integer before encoding processing according to the MIP mode. That is, after the encoder sets the offset parameter, for any current block, no matter what the size of the current block is, or no matter what the MIP mode number corresponding to the current block is, the offset parameter used is determined.

[0123] It should be noted that in the embodiments of the present application, the encoder can set the offset parameter as any positive integer when modifying the initial right shift parameters corresponding to different sizes and different MIP mode numbers uniformly according to the offset parameter. Specifically, the encoder can preferably set the offset parameter sW as 6, or preferably set the offset parameter sW as 7, or preferably set the offset parameter sW as 8, and can also preferably set the offset parameter sW as 9.

[0124] For example, Table 13 is a syntax description one of sW in the present application. In the embodiments of the present application, when modifying the initial right shift parameters corresponding to different sizes and different MIP mode numbers uniformly according to the offset parameter, the encoder can set sW corresponding to the luma block with size of 4x8, 8x4 or 8x8 and MIP mode number of 3, 8, 12 or 17 as the same value as sW corresponding to other luma blocks, i.e. when sW corresponding to other luma blocks is 8, sW corresponding to the luma block with size of 4x8, 8x4 or 8x8 and MIP mode number of 3, 8, 12 or 17 is set as 8, so that different current blocks can have the same offset parameter sW.

[0125] Table 13

[0126]

[0127] For example, Table 14 is a syntax description two of sW in the present application. In the embodiments of the present application, when modifying the initial right shift parameters corresponding to different sizes and different MIP mode numbers uniformly according to the offset parameter, the encoder can set sW corresponding to the luma block with size of 4x8, 8x4 or 8x8 and MIP mode number of 3, 8, 12 or 17 as the same value as sW corresponding to other luma blocks, i.e. when sW corresponding to other luma blocks is 7, sW corresponding to the luma block with size of 4x8, 8x4 or 8x8 and MIP mode number of 3, 8, 12 or 17 is set as 7, so that different current blocks can have the same offset parameter sW.

[0128] Table 14

[0129]

[0130] For example, Table 15 is a syntax description table of sW in the present application. In the embodiments of the present application, when the encoder unifies and modifies the initial right shift parameters corresponding to different sizes and different MIP mode numbers according to the offset parameter, for the luma block with size of 4x8, 8x4 or 8x8 and MIP mode number of 3, 8, 12 or 17, the corresponding sW can be set to the same value as the sW corresponding to other luma blocks, i.e. when the sW corresponding to other luma blocks is 8, the sW corresponding to the luma block with size of 4x8, 8x4 or 8x8 and MIP mode number of 3, 8, 12 or 17 is set to 8, so that different current blocks can have the same offset parameter sW.

[0131] Table 15

[0132]

[0133] As shown in Table 8, in the prior art, the offset parameter sW corresponding to different current blocks can be different, specifically, when and only when MipSizeId is equal to 1, i.e. the current block is a second type luma block with size of 4x8, 8x4 or 8x8 and MIP mode number of 3, 8, 12 or 17, the value of sW is different from the value of sW under all other MIP mode numbers. Therefore, when encoding the current block, the encoder needs to query and call the offset parameter sW according to the size and MIP mode number of the current block, which increases the overall time and reduces the coding efficiency. At the same time, since the syntax description table of sW needs to be stored, the storage space is also increased. Compared with the prior art, before encoding processing according to the MIP mode, the present application can first set the offset parameter sW, and set the offset parameter sW corresponding to all luma blocks with different sizes and different MIP mode numbers to the same value, so that when encoding the current block, the query and call of the offset parameter sW according to the size and MIP mode number of the current block is no longer needed, and the encoder also does not need to store the syntax description table of sW, thereby being able to reduce the storage space and overall time required in the coding process, and effectively improve the coding efficiency.

[0134] It should be noted that in the embodiments of the present application, although the encoder sets the offset parameter sW to the same value for all offset parameters sW corresponding to different sizes and different MIP mode numbers when setting the offset parameter sW, since the value of sW is different from the value of sW corresponding to all other MIP mode numbers only when MipSizeId is equal to 1, i.e., the current block is a second type of luma block, the size is 4x8, 8x4, 8x8, and the MIP mode number is 3, 8, 12, 17, the encoder sets the offset parameter sW corresponding to the size of 4x8, 8x4, 8x8, and the MIP mode number of 3, 8, 12, 17 when modifying the initial right shift parameter corresponding to different sizes and different MIP mode numbers by the offset parameter.

[0135] Therefore, in the embodiments of the present application, the process of the encoder modifying the initial right shift parameter corresponding to different sizes and different MIP mode numbers by the offset parameter is to modify the initial right shift parameter to the offset parameter when the initial right shift parameter and the offset parameter are different, so that the right shift number of all prediction values corresponding to all sizes and all MIP mode numbers is the same.

[0136] Step 102, when encoding according to the MIP mode, encoding according to the offset parameter.

[0137] In the embodiments of the present application, after the encoder modifies the initial right shift parameter corresponding to different sizes and different MIP mode numbers by the offset parameter, when the encoder encodes according to the MIP mode, the encoder can encode based on the set offset parameter.

[0138] It should be noted that in the embodiments of the present application, after the encoder sets the offset parameter, when the encoder encodes according to the MIP mode, the encoder can directly encode the current block according to the offset parameter. Thus, the storage space and the overall time required in the encoding and decoding process can be reduced on the basis of ensuring the coding and decoding performance, and the coding and decoding efficiency can be effectively improved.

[0139] In the embodiments of the present application, further, Figure 8 An implementation flow of an image encoding method proposed in the embodiments of the present application is shown in Figure 2 As shown in Figure 8 After the encoder modifies the initial right shift parameter corresponding to different sizes and different MIP mode numbers by the offset parameter, i.e., after step 101, the method of the encoder for image encoding can further include the following steps:

[0140] In step 103, the initial weight matrix and the initial bias matrix are modified according to a preset calculation rule to obtain a modified weight matrix and a modified bias matrix; the initial weight matrix and the initial bias matrix correspond to the initial right shift parameter that is uniformly modified.

[0141] In the embodiments of the present application, after the initial right shift parameters corresponding to different sizes and different MIP mode numbers are uniformly modified according to the offset parameter, the initial weight matrix and the initial bias matrix can be modified according to the preset calculation rule, so that the modified weight matrix and the modified bias matrix can be obtained.

[0142] It should be noted that in the embodiments of the present application, the initial weight matrix and the initial bias matrix correspond to the initial right shift parameter that is uniformly modified.

[0143] It should be noted that in the embodiments of the present application, the preset calculation rule can be used to update the corresponding initial weight matrix and the initial bias matrix when the size is 4x8, 8x4 or 8x8, and the MIP mode number is 3, 8, 12 or 17.

[0144] Further, in the embodiments of the present application, after the offset parameter is set, that is, the offset parameter corresponding to the size of 4x8, 8x4 or 8x8, and the MIP mode number of 3, 8, 12 or 17 is changed, in order to prevent the coding performance from being reduced, the corresponding initial weight matrix and the initial bias matrix can be further updated to obtain the modified weight matrix and the modified bias matrix.

[0145] It should be noted that in the embodiments of the present application, when the size is 4x8, 8x4 or 8x8, and the MIP mode number is 3, 8, 12 or 17, the encoder can update the corresponding initial weight matrix and initial bias matrix in multiple different ways when obtaining the modified weight matrix and modified bias matrix according to the pre-designed calculation rule. For example, when the size is 4x8, 8x4 or 8x8, and the MIP mode number is 3, 8, 12 or 17, the encoder can update any element value A in the initial weight matrix to A / 2 according to the down rounding calculation rule, and at the same time update any element value B in the initial bias matrix to B / 2, so as to obtain the modified weight matrix and the modified bias matrix. Wherein, A and B are integers. Further, the encoder can also update any element value A in the initial weight matrix to A / 2 according to the up rounding calculation rule, and at the same time update any element value B in the initial bias matrix to B / 2, so as to obtain the modified weight matrix and the modified bias matrix. Further, the encoder can also update any element value A in the initial weight matrix to A / 2 according to the rounding calculation rule, and at the same time update any element value B in the initial bias matrix to B / 2, so as to obtain the modified weight matrix and the modified bias matrix.

[0146] Step 104, performing encoding processing according to the offset parameter, the modified weight matrix and the modified bias matrix.

[0147] In the embodiments of the present application, when the encoder performs encoding processing according to the MIP mode, the encoding processing can be performed based on the set offset parameter, the modified weight matrix and the modified bias matrix.

[0148] It should be noted that in the embodiments of the present application, after the encoder sets the offset parameter, in order to prevent the decrease of the coding performance, the corresponding initial weight matrix and initial bias matrix are updated to obtain the modified weight matrix and the modified bias matrix, and then when the encoding processing is performed according to the MIP mode, the current block can be encoded and processed according to the offset parameter, the modified weight matrix and the modified bias matrix. Thus, the storage space and the overall time required in the encoding and decoding process can be reduced on the basis of ensuring the coding performance, and the coding efficiency can be effectively improved.

[0149] It should be noted that in the embodiments of the present application, after the encoder sets the offset parameter, the current block can also be encoded and processed directly according to the offset parameter, the initial weight matrix and the initial bias matrix. That is to say, after the encoder completes the setting of the offset parameter, the corresponding initial weight matrix and initial bias matrix can also not be updated.

[0150] In the prior art, when the current block is predicted by the MIP mode, the number of bits to be right shifted is not uniform, that is, the offset parameter sW is not the same, and the image coding method provided in the present application uniformly sets the offset parameter, so that the implementation of the MIP mode is more simple and uniform. Further, because the offset parameter sW is not the same in the prior art, a sW table representing the number of bits to be right shifted needs to be stored, and in the calculation process, the sW corresponding to the current block is queried and called to determine the number of bits to be right shifted in the MIP calculation of the prediction value. However, because the offset parameter is uniformly set in the image coding method provided in the present application, the sW table representing the number of bits to be right shifted no longer needs to be stored, thereby saving storage space and eliminating the processing flow of querying and calling sW.

[0151] Further, in the embodiments of the present application, after the offset parameter is set, the corresponding initial weight matrix and initial bias matrix can also be updated, so that the coding and decoding performance is not obviously lost. Specifically, according to the VVC test standard, the BD-rate on Y, U and V is 0.00%, -0.02% and -0.02% respectively, and the results at 24 frame intervals are expected to be similar to the coding and decoding performance at 8 frame intervals.

[0152] The image coding method provided in the embodiments of the present application uniformly modifies the initial right shift parameter corresponding to different sizes and different MIP mode numbers according to the offset parameter before the encoder performs coding processing according to the MIP mode; wherein the offset parameter is used to indicate the number of bits to be right shifted in the prediction value; and when coding processing is performed according to the MIP mode, the coding processing is performed according to the offset parameter. As can be seen, the image coding and decoding method provided in the present application uniformly modifies the number of bits to be right shifted in the prediction value by using the offset parameter, so that all the Y blocks of different sizes and different MIP mode numbers have the same sW value, thereby eliminating the need to query and call sW value when coding and decoding processing is performed, reducing the complexity of the MIP algorithm, and reducing the storage space and overall time required in the coding and decoding process on the basis of ensuring the coding and decoding performance, thereby effectively improving the coding and decoding efficiency.

[0153] Based on the above embodiments, in another embodiment of the present application, when the size is 4x8, 8x4 or 8x8, and the MIP mode number is 3, 8, 12 or 17, the method of the encoder for obtaining the modified weight matrix and the modified bias matrix according to the pre-designed calculation rule can include the following steps:

[0154] Step 103a, according to the calculation rule of taking the integer part downward, the values of all elements in the initial weight matrix are modified to the values of the same binary order of magnitude as the values of other weight matrix elements, to obtain the modified weight matrix.

[0155] Step 103b, according to the down-round calculation rule, modifying all elements in the initial bias matrix to the value of the same binary order of magnitude as the value of other bias matrix elements, to obtain the modified bias matrix.

[0156] In the embodiments of the present application, when the size is 4x8, 8x4 or 8x8, and the MIP mode number is 3, 8, 12 or 17, the encoder can modify all element values in the initial weight matrix to the value of the same binary order of magnitude as the value of other weight matrix elements according to the down-round calculation rule, and modify all elements in the initial bias matrix to the value of the same binary order of magnitude as the value of other bias matrix elements, so as to obtain the modified weight matrix and the modified bias matrix.

[0157] Based on the above Table 9, Table 16 is the modified weight matrix when MipSizeId is 1, the MIP mode number is 3 and 12, as shown in Table 16, the encoder updates each element value A in Table 9 to A / 2 according to the down-round calculation rule, thereby obtaining the modified weight matrix when MipSizeId is 1, the MIP mode number is 3 and 12.

[0158] Table 16

[0159] 109 -28 4 -2 205 -38 6 -2 224 47 -23 3 11 -8 1 -2 -1 238 38 -17 -3 -1 0 -2 0 -8 233 30 2 -2 0 -2 -19 1 -2 0 130 179 -39 4 61 -20 0 -1 231 -13 -6 -1 202 27 -21 2 60 -17 1 -3 53 201 8 -6 1 -2 0 -3 2 -1 -1 0 -31 133 187 -37 -13 1 -2 -1 54 233 -14 -6 29 -13 -2 -1 209 48 -18 -2 150 9 -8 2 114 -11 -2 -4 -1 -2 -1 -1 12 -48 145 148 1 0 -3 -1 -15 51 232 -15 -8 0 -3 0 20 214 35 -7 13 -3 -1 0 151 96 -7 -1

[0160] Based on the above Table 10, Table 17 is the modified bias matrix when MipSizeId is 1, the MIP mode number is 3 and 12, as shown in Table 17, the encoder updates each element value B in Table 10 to B / 2 according to the down-round calculation rule, thereby obtaining the modified bias matrix when MipSizeId is 1, the MIP mode number is 3 and 12.

[0161] Table 17

[0162] 0 1 1 0 0 1 1 1 1 2 2 2 1 2 2 2

[0163] Based on the above Table 11, Table 18 is the modified weight matrix when MipSizeId is 1, the MIP mode number is 8 and 17, as shown in Table 18, the encoder updates each element value A in Table 11 to A / 2 according to the down-round calculation rule, thereby obtaining the modified weight matrix when MipSizeId is 1, the MIP mode number is 8 and 17.

[0164] Table 18

[0165] -46 11 6 4 104 130 36 12 -13 -11 7 6 44 153 57 17 -8 9 -8 2 15 163 67 19 -6 5 15 -10 1 162 71 20 6 -2 0 0 -7 136 113 13 1 5 -2 -3 3 115 124 17 0 4 2 -5 5 107 131 18 -1 5 2 -4 7 104 129 20 2 0 2 -2 3 46 170 39 2 3 0 -3 3 56 164 37 1 6 1 -4 3 61 159 37 0 6 3 -5 4 68 151 37 3 0 2 -3 4 19 108 126 2 5 0 -4 4 29 156 70 1 6 2 -4 5 35 163 57 1 7 2 -4 7 41 157 55

[0166] Based on the above Table 12, Table 19 is the modified bias matrix when MipSizeId is 1, MIP mode number is 8 and 17, as shown in Table 22, the encoder updates each element value B in Table 12 to B / 2 according to the rounding down calculation rule, thereby obtaining the modified bias matrix when MipSizeId is 1, MIP mode number is 8 and 17.

[0167] Table 19

[0168] -4 -5 -6 -6 -5 -7 -9 -9 -6 -8 -10 -11 -5 -9 -11 -11

[0169] In the embodiments of the present application, further, when the size is 4x8, 8x4 or 8x8, and the MIP mode number is 3, 8, 12 or 17, the method that the encoder obtains the modified weight matrix and the modified bias matrix according to the pre-designed calculation rule can include the following steps:

[0170] Step 103c, modifying all element values in the initial weight matrix to the value of the same binary order of magnitude as other weight matrix element values according to the rounding up calculation rule, to obtain the modified weight matrix.

[0171] Step 103d, modifying all elements in the initial bias matrix to the value of the same binary order of magnitude as other bias matrix element values according to the rounding up calculation rule, to obtain the modified bias matrix.

[0172] In the embodiments of the present application, when the size is 4x8, 8x4 or 8x8, and the MIP mode number is 3, 8, 12 or 17, the encoder can modify all element values in the initial weight matrix to the value of the same binary order of magnitude as other weight matrix element values according to the rounding up calculation rule, and modify all elements in the initial bias matrix to the value of the same binary order of magnitude as other bias matrix element values, thereby the modified weight matrix and the modified bias matrix can be obtained.

[0173] Based on the above Table 9, Table 20 is the modified weight matrix when MipSizeId is 1, MIP mode number is 3 and 12, as shown in Table 20, the encoder updates each element value A in Table 9 to A / 2 according to the rounding up calculation rule, thereby obtaining the modified weight matrix when MipSizeId is 1, MIP mode number is 3 and 12.

[0174] Table 20

[0175] 109 -28 5 -1 206 -38 6 -2 224 47 -22 3 12 -7 1 -1 0 238 39 -17 -2 -1 1 -1 1 -8 233 31 3 -2 1 -1 -19 1 -1 0 130 179 -38 4 61 -19 1 0 232 -12 -5 -1 203 27 -20 3 61 -16 1 -3 54 201 8 -6 2 -2 1 -3 3 0 0 0 -31 134 188 -36 -12 2 -2 0 54 233 -14 -5 29 -12 -1 0 209 48 -17 -1 151 9 -7 3 115 -10 -2 -3 0 -1 -1 -1 12 -47 146 149 2 1 -2 -1 -15 52 232 -14 -8 0 -3 0 21 215 35 -6 14 -2 -1 1 152 97 -6 0

[0176] Based on the above Table 10, Table 21 is the modified weight matrix when MipSizeId is 1, MIP mode number is 3 and 12, as shown in Table 21, the encoder updates each element value B in Table 10 to B / 2 according to the rounding up calculation rule, thereby obtaining the modified weight matrix when MipSizeId is 1, MIP mode number is 3 and 12.

[0177] Table 21

[0178] 1 1 2 1 1 2 2 2 1 2 2 2 2 3 3 3

[0179] Based on the above Table 11, Table 22 is the modified weight matrix when MipSizeId is 1, MIP mode number is 8 and 17, as shown in Table 22, the encoder updates each element value A in Table 11 to A / 2 according to the rounding up calculation rule, thereby obtaining the modified weight matrix when MipSizeId is 1, MIP mode number is 8 and 17.

[0180] Table 22

[0181] -45 12 7 4 105 131 36 12 -13 -11 7 7 44 153 57 18 -8 9 -8 3 16 164 68 20 -5 6 15 -9 2 163 71 21 6 -2 1 1 -7 137 114 13 2 5 -1 -2 3 116 125 17 1 4 3 -4 5 107 131 19 0 6 2 -3 8 104 130 20 3 0 2 -2 3 46 170 39 2 3 1 -2 3 57 165 38 1 7 1 -4 3 62 160 38 1 7 3 -5 5 68 152 37 3 1 2 -2 4 19 109 126 2 5 1 -3 5 29 157 71 2 6 2 -4 6 35 164 57 1 7 2 -3 7 41 157 55

[0182] Based on the above Table 12, Table 23 is the modified weight matrix when MipSizeId is 1, MIP mode number is 8 and 17, as shown in Table 23, the encoder updates each element value B in Table 12 to B / 2 according to the rounding up calculation rule, thereby obtaining the modified weight matrix when MipSizeId is 1, MIP mode number is 8 and 17.

[0183] Table 23

[0184] -3 -5 -5 -5 -5 -7 -8 -9 -5 -7 -9 -10 -5 -8 -10 -11

[0185] In the embodiments of the present application, further, when the size is 4x8, 8x4 or 8x8, and the MIP mode number is 3, 8, 12 or 17, the method for the encoder to obtain the modified weight matrix and the modified bias matrix according to the pre-designed calculation rule can include the following steps:

[0186] Step 103e, modify all element values in the initial weight matrix to values of the same binary order of magnitude as other weight matrix element values according to the rounding calculation rule, to obtain the modified weight matrix.

[0187] Step 103f, modify all elements in the initial bias matrix to values of the same binary order of magnitude as other bias matrix element values according to the rounding calculation rule, to obtain the modified bias matrix.

[0188] In the embodiments of the present application, when the size is 4x8, 8x4 or 8x8, and the MIP mode number is 3, 8, 12 or 17, the encoder can modify all element values in the initial weight matrix to values of the same binary order of magnitude as other weight matrix element values according to the rounding calculation rule, and modify all elements in the initial bias matrix to values of the same binary order of magnitude as other bias matrix element values, so as to obtain the modified weight matrix and the modified bias matrix.

[0189] Based on the above Table 9, Table 24 is the modified weight matrix when MipSizeId is 1, the MIP mode number is 3 and 12. As shown in Table 24, the encoder updates each element value A in Table 9 to A / 2 according to the rounding calculation rule, so as to obtain the modified weight matrix when MipSizeId is 1, the MIP mode number is 3 and 12.

[0190] Table 24

[0191] 109 -28 5 -2 206 -38 6 -2 224 47 -23 3 12 -8 1 -2 -1 238 39 -17 -3 -1 1 -2 1 -8 233 31 3 -2 1 -2 -19 1 -2 0 130 179 -39 4 61 -20 1 -1 232 -13 -6 -1 203 27 -21 3 61 -17 1 -3 54 201 8 -6 2 -2 1 -3 3 -1 -1 0 -31 134 188 -37 -13 2 -2 -1 54 233 -14 -6 29 -13 -2 -1 209 48 -18 -2 151 9 -8 3 115 -11 -2 -4 -1 -2 -1 -1 12 -48 146 149 2 1 -3 -1 -15 52 232 -15 -8 0 -3 0 21 215 35 -7 14 -3 -1 1 152 97 -7 -1

[0192] Based on the above Table 10, Table 25 is the modified bias matrix when MipSizeId is 1, the MIP mode number is 3 and 12. As shown in Table 25, the encoder updates each element value B in Table 10 to B / 2 according to the rounding calculation rule, so as to obtain the modified bias matrix when MipSizeId is 1, the MIP mode number is 3 and 12.

[0193] Table 25

[0194] 1 1 2 1 1 2 2 2 1 2 2 2 2 3 3 3

[0195] Based on the above Table 11, Table 26 is the modified weight matrix when MipSizeId is 1, the MIP mode number is 8 and 17. As shown in Table 26, the encoder updates each element value A in Table 11 to A / 2 according to the rounding calculation rule, so as to obtain the modified weight matrix when MipSizeId is 1, the MIP mode number is 8 and 17.

[0196] Table 26

[0197] -46 12 7 4 105 131 36 12 -13 -11 7 7 44 153 57 18 -8 9 -8 3 16 164 68 20 -6 6 15 -10 2 163 71 21 6 -2 1 1 -7 137 114 13 2 5 -2 -3 3 116 125 17 1 4 3 -5 5 107 131 19 -1 6 2 -4 8 104 130 20 3 0 2 -2 3 46 170 39 2 3 1 -3 3 57 165 38 1 7 1 -4 3 62 160 38 1 7 3 -5 5 68 152 37 3 1 2 -3 4 19 109 126 2 5 1 -4 5 29 157 71 2 6 2 -4 6 35 164 57 1 7 2 -4 7 41 157 55

[0198] Based on the above Table 12, Table 27 is the modified bias matrix when MipSizeId is 1, the MIP mode number is 8 and 17. As shown in Table 30, the encoder updates each element value B in Table 12 to B / 2 according to the rounding calculation rule, so as to obtain the modified bias matrix when MipSizeId is 1, the MIP mode number is 8 and 17.

[0199] Table 27

[0200] -4 -5 -6 -6 -5 -7 -9 -9 -6 -8 -10 -11 -5 -9 -11 -11

[0201] The image coding method proposed in the embodiments of the present application can unify and modify the initial right shift parameters corresponding to different sizes and different MIP mode numbers according to the offset parameter before the encoding processing according to the MIP mode, wherein the offset parameter is used to indicate the right shift number of the prediction value; and the encoding processing is performed according to the offset parameter when the encoding processing according to the MIP mode is performed. It can be seen that, by using the offset parameter to unify and modify the right shift number of the prediction value, the image coding and decoding method proposed in the present application can make all the luma blocks of different sizes and different MIP mode numbers have the same sW value, so that the sW value does not need to be queried and called when the coding and decoding processing is performed, the complexity of the MIP algorithm can be reduced, the storage space and the overall time required in the coding and decoding process can be reduced on the basis of ensuring the coding and decoding performance, and the coding and decoding efficiency can be effectively improved.

[0202] In another embodiment of the present application, Figure 9 The implementation flow of the image decoding method proposed in the embodiments of the present application is shown in Figure 1 As shown in Figure 9 In the embodiments of the present application, the method of the decoder for image decoding can include the following steps.

[0203] Step 201, before the decoding processing according to the MIP mode, the initial right shift parameters corresponding to different sizes and different MIP mode numbers are unified and modified according to the offset parameter; wherein the offset parameter is used to indicate the right shift number of the prediction value.

[0204] In the embodiments of the present application, before the decoding processing according to the MIP mode, the decoder can first set the offset parameter used to indicate the offset number.

[0205] It should be noted that, in the embodiments of the present application, based on the above formula (2), the offset parameter is sW in formula (2), that is, the offset parameter is the right shift amount of the overall prediction value, that is, when the luma prediction of the current block is performed, the offset parameter is used to indicate the right shift number of the overall prediction value of the current block.

[0206] Further, in the embodiments of the present application, the decoder can set the offset parameter to a fixed positive integer before the decoding processing according to the MIP mode. That is, after the decoder sets the offset parameter, for any current block, no matter what the size of the current block is, or no matter what the MIP mode number corresponding to the current block is, the offset parameter used is determined.

[0207] It should be noted that in the embodiments of the present application, when the decoder uniformly modifies the initial right shift parameters corresponding to different sizes and different MIP mode numbers according to the offset parameter, the offset parameter can be set to any positive integer. Specifically, the decoder can preferably set the offset parameter sW to 6, or preferably set the offset parameter sW to 7, or preferably set the offset parameter sW to 8, or preferably set the offset parameter sW to 9.

[0208] In the prior art, the offset parameter sW corresponding to different current blocks can be different. Specifically, the value of sW is different from that of all other MIP mode numbers when and only when MipSizeId is equal to 1, i.e., the current block is a second type of luma block with a size of 4x8, 8x4, 8x8, and the MIP mode number is 3, 8, 12, or 17. Therefore, when decoding the current block, the decoder needs to query and call the offset parameter sW according to the size and MIP mode number of the current block, thereby increasing the overall time and reducing the coding efficiency. At the same time, since the syntax description table of sW needs to be stored, the storage space is also increased. Compared with the prior art, the present application can set the offset parameter sW before decoding according to the MIP mode. The offset parameters sW corresponding to all luma blocks of different sizes and different MIP mode numbers are set to the same value, so that when decoding the current block, the offset parameter sW no longer needs to be queried and called according to the size and MIP mode number of the current block, and the decoder also does not need to store the syntax description table of sW, thereby reducing the storage space and overall time required in the coding process, and effectively improving the coding efficiency.

[0209] It should be noted that in the embodiments of the present application, although the decoder sets all offset parameters sW corresponding to different sizes and different MIP mode numbers to the same value when setting the offset parameter sW, since the value of sW is different from that of all other MIP mode numbers when and only when MipSizeId is equal to 1, i.e., the current block is a second type of luma block with a size of 4x8, 8x4, 8x8, and the MIP mode number is 3, 8, 12, or 17, the decoder uniformly modifies the initial right shift parameters corresponding to different sizes and different MIP mode numbers according to the offset parameter sW, which sets the offset parameter sW corresponding to the size of 4x8, 8x4, 8x8, and the MIP mode number of 3, 8, 12, or 17.

[0210] Therefore, in the embodiment of the present application, the process that the decoder uniformly modifies the initial right shift parameters corresponding to different sizes and different MIP mode numbers according to the offset parameter is that when the initial right shift parameter and the offset parameter are different, the initial right shift parameter is modified to the offset parameter, so that the right shift numbers of all prediction values corresponding to all sizes and all MIP mode numbers are the same.

[0211] Step 202, when decoding according to the MIP mode, decoding according to the offset parameter.

[0212] In the embodiment of the present application, after the decoder uniformly modifies the initial right shift parameters corresponding to different sizes and different MIP mode numbers according to the offset parameter, when the decoder decodes according to the MIP mode, the decoding can be performed based on the set offset parameter.

[0213] It should be noted that in the embodiment of the present application, after the offset parameter is set, when decoding according to the MIP mode, the current block can be directly decoded according to the offset parameter. Thus, the storage space and the overall time required in the encoding and decoding process can be reduced on the basis of ensuring the coding performance, and the coding efficiency can be effectively improved.

[0214] In the embodiment of the present application, further, Figure 10 An implementation flow of an image decoding method proposed in the embodiment of the present application is shown in Figure 2 As shown in Figure 10 After the decoder uniformly modifies the initial right shift parameters corresponding to different sizes and different MIP mode numbers according to the offset parameter, that is, after step 201, the method for the decoder to decode the image can further include the following steps:

[0215] Step 203, modifying the initial weight matrix and the initial bias matrix according to a pre-designed calculation rule to obtain a modified weight matrix and a modified bias matrix; wherein the initial weight matrix and the initial bias matrix correspond to the uniformly modified initial right shift parameter.

[0216] In the embodiment of the present application, after the decoder uniformly modifies the initial right shift parameters corresponding to different sizes and different MIP mode numbers according to the offset parameter, the initial weight matrix and the initial bias matrix can be modified according to a pre-designed calculation rule, so that a modified weight matrix and a modified bias matrix can be obtained.

[0217] It should be noted that in the embodiment of the present application, the initial weight matrix and the initial bias matrix correspond to the uniformly modified initial right shift parameter.

[0218] It should be noted that in the embodiments of the present application, the pre-designed calculation rule can be used to update the initial weight matrix and the initial bias matrix corresponding to the size of 4x8, 8x4 or 8x8 and the MIP mode number of 3, 8, 12 or 17.

[0219] Further, in the embodiments of the present application, after the decoder sets the offset parameter, i.e., changes the offset parameter corresponding to the size of 4x8, 8x4 or 8x8 and the MIP mode number of 3, 8, 12 or 17, in order to prevent the coding performance from being reduced, the corresponding initial weight matrix and initial bias matrix can be further updated to obtain the modified weight matrix and the modified bias matrix.

[0220] It should be noted that in the embodiments of the present application, when the decoder obtains the modified weight matrix and the modified bias matrix according to the pre-designed calculation rule, the initial weight matrix and the initial bias matrix corresponding to the size of 4x8, 8x4 or 8x8 and the MIP mode number of 3, 8, 12 or 17 can be updated by various methods. For example, when the size is 4x8, 8x4 or 8x8 and the MIP mode number is 3, 8, 12 or 17, the decoder can update any element value A in the initial weight matrix to A / 2 and update any element value B in the initial bias matrix to B / 2 according to the calculation rule of rounding down, so as to obtain the modified weight matrix and the modified bias matrix. Wherein, A and B are integers. Further, the decoder can also update any element value A in the initial weight matrix to A / 2 and update any element value B in the initial bias matrix to B / 2 according to the calculation rule of rounding up, so as to obtain the modified weight matrix and the modified bias matrix. Further, the decoder can also update any element value A in the initial weight matrix to A / 2 and update any element value B in the initial bias matrix to B / 2 according to the calculation rule of rounding, so as to obtain the modified weight matrix and the modified bias matrix.

[0221] Step 204, decoding processing is performed according to the offset parameter, the modified weight matrix and the modified bias matrix.

[0222] In the embodiments of the present application, when the decoder performs decoding processing according to the MIP mode, decoding processing can be performed based on the set offset parameter, the modified weight matrix and the modified bias matrix.

[0223] It should be noted that in the embodiments of the present application, after the offset parameter is set, the decoder will also update the corresponding initial weight matrix and initial bias matrix in order to place the reduction of the coding performance, and then obtain the modified weight matrix and the modified bias matrix, and then when decoding processing is performed according to the MIP mode, the current block can be decoded and processed according to the offset parameter, the modified weight matrix and the modified bias matrix. Thus, the storage space and the overall time required in the coding process can be reduced on the basis of ensuring the coding performance, and the coding efficiency can be effectively improved.

[0224] It should be noted that in the embodiments of the present application, after the offset parameter is set, the decoder can directly decode and process the current block according to the offset parameter, the initial weight matrix and the initial bias matrix. That is, after the setting of the offset parameter is completed, the corresponding initial weight matrix and initial bias matrix can also not be updated.

[0225] In the prior art, when the current block is predicted by the MIP mode, the number of bits to be right shifted is not uniform, that is, the offset parameter sW is not the same. The image decoding method proposed in the present application uniformly sets the offset parameter, so that the implementation of the MIP mode is more simple and unified. Further, because the offset parameter sW is not the same in the prior art, a sW table representing the number of bits to be right shifted needs to be stored, and in the calculation process, the sW corresponding to the current block is queried and called to determine the number of bits to be right shifted of the prediction value of the MIP calculation. However, because the offset parameter is uniformly set in the image decoding method proposed in the present application, the sW table representing the number of bits to be right shifted no longer needs to be stored, thereby saving storage space and eliminating the processing procedure of querying and calling sW.

[0226] The image decoding method proposed in the embodiments of the present application uniformly modifies the initial right shift parameter corresponding to different sizes and different MIP mode numbers according to the offset parameter before the decoder performs decoding processing according to the MIP mode. The offset parameter is used to indicate the number of bits to be right shifted of the prediction value. When decoding processing is performed according to the MIP mode, the decoding processing is performed according to the offset parameter. It can be seen that the image coding and decoding method proposed in the present application uniformly modifies the number of bits to be right shifted of the prediction value by using the offset parameter, so that all the brightness blocks of different sizes and different MIP mode numbers have the same sW value. Therefore, when coding and decoding processing is performed, the sW value does not need to be queried and called, the complexity of the MIP algorithm can be reduced, the storage space and the overall time required in the coding process can be reduced on the basis of ensuring the coding performance, and the coding efficiency can be effectively improved.

[0227] Based on the above embodiments, in another embodiment of the present application, Figure 11Structure of an encoder according to an embodiment of the present application Figure 1 As shown in Figure 11 The encoder 300 according to an embodiment of the present application can include a first modification part 301 and an encoding part 302.

[0228] The first modification part 301 is configured to modify the initial right shift parameters corresponding to different sizes and different MIP mode numbers uniformly according to an offset parameter before encoding processing according to the MIP mode, wherein the offset parameter is used to indicate the right shift number of the prediction value.

[0229] The encoding part 302 is configured to perform encoding processing according to the offset parameter when performing encoding processing according to the MIP mode.

[0230] The first modification part 301 is specifically configured to modify the initial right shift parameter to the offset parameter when the initial right shift parameter and the offset parameter are different, so that the right shift numbers of all prediction values corresponding to all sizes and all MIP mode numbers are the same.

[0231] Figure 12 Structure of an encoder according to an embodiment of the present application Figure 2 As shown in Figure 12 The encoder 300 according to an embodiment of the present application can further include a first processor 303, a first memory 304 storing executable instructions of the first processor 303, a first communication interface 305, and a first bus 306 for connecting the first processor 303, the first memory 304, and the first communication interface 305.

[0232] Further, in the embodiment of the present application, the first processor 303 is used to modify the initial right shift parameters corresponding to different sizes and different MIP mode numbers uniformly according to an offset parameter before encoding processing according to the MIP mode, wherein the offset parameter is used to indicate the right shift number of the prediction value; and perform encoding processing according to the offset parameter when performing encoding processing according to the MIP mode.

[0233] In addition, each functional module in the embodiment can be integrated in one processing unit, or each unit can exist physically independently, or two or more units can be integrated in one unit. The integrated unit can be realized in the form of hardware or in the form of a software functional module.

[0234] If the integrated unit is implemented in the form of a software function module and is not sold or used as an independent product, it can be stored in a computer readable storage medium based on such understanding. The technical solutions of the embodiments essentially or the part that contributes to the prior art or the whole or part of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes a plurality of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) or a processor to execute all or part of the steps of the embodiments. The aforementioned storage medium includes a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and various media that can store program codes.

[0235] The embodiment of the present application provides a kind of encoder, it is before being encoded according to MIP mode processing, according to the initial right shift parameter corresponding to different size and different MIP mode number is unifiedly modified according to offset parameter;Wherein, offset parameter is used to indicate the right shift number of prediction value;And, when being encoded according to MIP mode processing, according to offset parameter is encoded processing.It can be seen from this, the image coding method proposed in the present application, by using offset parameter, the right shift number of prediction value is unifiedly modified, so that all luminance blocks of different size, different MIP mode number have the same sW value, so that when coding processing, sW value does not need to be inquired and called, the complexity of MIP algorithm can be reduced, the storage space and overall time required in coding process can be reduced on the basis of guaranteeing coding performance, effectively improve coding efficiency.

[0236] Figure 13 The composition structure of the decoder proposed in the embodiment of the present application is shown Figure 1 As Figure 13 shown, the decoder 400 proposed in the embodiment of the present application can include a second modification part 401 and a decoding part 402.

[0237] The second modification part 401 is configured to, before decoding according to MIP mode processing, uniformly modify the initial right shift parameter corresponding to different size and different MIP mode number according to offset parameter;Wherein, the offset parameter is used to indicate the right shift number of prediction value.

[0238] The decoding part 402 is configured to, when decoding according to the MIP mode processing, according to the offset parameter is decoded processing.

[0239] The second modification 401 is specifically configured to modify the initial right shift parameter to the offset parameter when the initial right shift parameter and the offset parameter are not the same, so that the right shift bits of all predicted values ​​corresponding to all sizes and all MIP mode numbers are the same.

[0240] Figure 14 A schematic diagram of the decoder structure proposed in the embodiments of this application. Figure 2 ,like Figure 14 As shown, the decoder 400 proposed in this application embodiment may further include a second processor 403, a second memory 404 storing executable instructions of the second processor 403, a second communication interface 405, and a second bus 406 for connecting the second processor 403, the second memory 404, and the second communication interface 405.

[0241] Furthermore, in the embodiments of this application, the second processor 403 is configured to uniformly modify the initial right shift parameters corresponding to different sizes and different MIP mode numbers according to the offset parameter before performing decoding processing according to the MIP mode; wherein, the offset parameter is used to indicate the number of right shifts of the predicted value; and, when performing decoding processing according to the MIP mode, performing decoding processing according to the offset parameter.

[0242] Furthermore, in this embodiment, the functional modules can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional module.

[0243] If the integrated unit is implemented as a software functional module and is not sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this embodiment, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) or processor to execute all or part of the steps of the method of this embodiment. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0244] The embodiment of the present application provides an encoder, which uniformly modifies initial right shift parameters corresponding to different sizes and different MIP mode numbers according to an offset parameter before decoding processing according to a MIP mode; and performs decoding processing according to the offset parameter when decoding processing according to the MIP mode. It can be seen that, by uniformly modifying the right shift number of a prediction value by using the offset parameter, the image coding and decoding method provided by the present application makes all the luma blocks of different sizes and different MIP mode numbers have the same sW value, so that the sW value does not need to be queried and called when coding and decoding processing is performed, the complexity of the MIP algorithm can be reduced, the storage space and the overall time required in the coding and decoding process can be reduced on the basis of ensuring the coding and decoding performance, and the coding and decoding efficiency is effectively improved.

[0245] The embodiment of the present application provides a computer readable storage medium and a computer readable storage medium, which stores a program, and the program is executed by a processor to implement the method described in the above embodiment.

[0246] Specifically, the program instructions corresponding to the image coding method in the embodiment can be stored on a storage medium such as an optical disc, a hard disk, a U disk, etc., and when the program instructions corresponding to the image coding method in the storage medium are read or executed by an electronic device, the following steps are included:

[0247] Before coding processing according to a MIP mode, uniformly modifying initial right shift parameters corresponding to different sizes and different MIP mode numbers according to an offset parameter; wherein the offset parameter is used to indicate the right shift number of a prediction value; and

[0248] When coding processing according to the MIP mode, performing coding processing according to the offset parameter.

[0249] Specifically, the program instructions corresponding to the image decoding method in the embodiment can be stored on a storage medium such as an optical disc, a hard disk, a U disk, etc., and when the program instructions corresponding to the image decoding method in the storage medium are read or executed by an electronic device, the following steps are included:

[0250] Before decoding processing according to a MIP mode, uniformly modifying initial right shift parameters corresponding to different sizes and different MIP mode numbers according to an offset parameter; wherein the offset parameter is used to indicate the right shift number of a prediction value; and

[0251] When decoding processing according to the MIP mode, performing decoding processing according to the offset parameter.

[0252] Those skilled in the art will appreciate that embodiments of the present application can be readily used as software, hardware, or a combination of software and hardware. In one example, the present application can be implemented using PC based software. In another example, the present application can be implemented using a specially designed machine, such as a computer based system. In yet another example, the present application can be implemented by utilizing a conventional computer or data processing device.

[0253] The present application is described in terms of implementation and blocking diagrams and / or flow charts according to embodiments of the present application. It should be appreciated that each block of the block diagrams and / or flow charts, and combinations thereof, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general purpose computer, special purpose computer, embedded processing element, or other programmable data processing device to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing device, implement the functions specified in the block diagrams and / or flow charts block or blocks. Figure 1 one or more functions specified in the flow diagram and / or block diagram block or blocks. Figure 1 one or more functions specified in the flow diagram and / or block diagram block or blocks.

[0254] These computer program instructions can also be stored in a computer readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture including instructions which implement the function specified in the flow diagram and / or block diagram block or blocks. Figure 1 one or more functions specified in the flow diagram and / or block diagram block or blocks. Figure 1 one or more functions specified in the flow diagram and / or block diagram block or blocks.

[0255] The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the function specified in the flow diagram and / or block diagram block or blocks. Figure 1 one or more functions specified in the flow diagram and / or block diagram block or blocks. Figure 1 one or more functions specified in the flow diagram and / or block diagram block or blocks.

[0256] The foregoing is merely exemplary and is not intended to limit the scope of the present application.

[0257] Industrial applicability

[0258] The embodiment of the present application provides an image coding method, an encoder, a decoder and a storage medium. The encoder modifies the initial right shift parameters corresponding to different sizes and different MIP mode numbers uniformly according to an offset parameter before encoding processing according to the MIP mode; wherein the offset parameter is used to indicate the right shift number of the prediction value; and the encoding processing is performed according to the offset parameter when the encoding processing is performed according to the MIP mode. The decoder modifies the initial right shift parameters corresponding to different sizes and different MIP mode numbers uniformly according to an offset parameter before decoding processing according to the MIP mode; and the decoding processing is performed according to the offset parameter when the decoding processing is performed according to the MIP mode. It can be seen that the image coding method provided by the present application modifies the right shift number of the prediction value uniformly by using the offset parameter, so that all the luminance blocks with different sizes and different MIP mode numbers have the same sW value, thereby when the coding processing is performed, the sW value does not need to be queried and called, the complexity of the MIP algorithm can be reduced, the storage space and the overall time required in the coding process can be reduced on the basis of ensuring the coding performance, and the coding efficiency can be effectively improved.

Claims

1. An image encoding method applied to an encoder, the method comprising: Determine the mode parameters for the current block; When the mode parameter indicates that the predicted value of the current block is determined according to the matrix-based intra-frame prediction (MIP) mode, the current block is predicted according to the MIP mode based on the offset parameter, which indicates a uniform right shift number calculated for predicted values ​​of all block sizes and all MIP modes.

2. The method according to claim 1, wherein, The offset parameter is a fixed positive integer.

3. The method according to claim 2, wherein, The offset parameter is 6.

4. The method according to claim 1, wherein, The step of predicting the current block according to the offset parameter in the MIP mode includes: The current block is predicted based on the offset parameter and the weight matrix.

5. The method according to claim 1, wherein, The method further includes: Write the mode parameters of the current block into the bitstream.

6. An image decoding method, applied to a decoder, the method comprising: Determine the mode parameters for the current block; When the mode parameter indicates that the predicted value of the current block is determined according to the matrix-based intra-frame prediction (MIP) mode, the current block is predicted according to the MIP mode based on the offset parameter, which indicates a uniform right shift number calculated for predicted values ​​of all block sizes and all MIP modes.

7. The method according to claim 6, wherein, The offset parameter is a fixed positive integer.

8. The method according to claim 7, wherein, The offset parameter is 6.

9. The method according to claim 6, wherein, The step of predicting the current block according to the offset parameter in the MIP mode includes: The current block is predicted based on the offset parameter and the weight matrix.

10. The method according to claim 6, wherein, The method further includes: Parse the bitstream to determine the mode parameters of the current block.

11. An encoder, the encoder comprising a first processor, a first memory storing instructions executable by the first processor, a first communication interface, and a first bus for connecting the first processor, the first memory, and the first communication interface, wherein when the instructions are executed by the first processor, the method of any one of claims 1-5 is implemented.

12. A decoder, the decoder comprising a second processor, a second memory storing instructions executable by the second processor, a second communication interface, and a second bus for connecting the second processor, the second memory, and the second communication interface, wherein when the instructions are executed by the second processor, the decoder implements the method as described in any one of claims 6-10.

13. A computer-readable storage medium having a program stored thereon, applied in an encoder, wherein the program, when executed by a processor, implements the method as described in any one of claims 1-5.

14. A computer-readable storage medium having a program stored thereon, applied in a decoder, wherein the program, when executed by a processor, implements the method as described in any one of claims 6-10.

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