CN117478871A

CN117478871A - Video image processing method, device and storage medium

Info

Publication number: CN117478871A
Application number: CN202311412768.5A
Authority: CN
Inventors: 马思伟; 张嘉琪; 郑萧桢; 王苫社
Original assignee: Peking University; SZ DJI Technology Co Ltd
Current assignee: Peking University; SZ DJI Technology Co Ltd
Priority date: 2019-06-25
Filing date: 2019-06-25
Publication date: 2024-01-30
Also published as: CN111699681B; WO2020258056A1; CN111699681A; WO2020258378A1

Abstract

The embodiment of the invention provides a video image processing method, video image processing equipment and a storage medium, wherein the method comprises the following steps: binarizing a chrominance prediction mode of an image block of an image to be encoded/decoded to obtain a bit string, wherein the bit string comprises at least three adjacent bits, the image to be encoded/decoded allows a CCLM and/or a conventional intra-frame chrominance prediction mode to be used, and the CCLM at least comprises a first mode, a second mode and a third mode; the first bit is used for indicating whether a first mode is adopted, the second bit is used for indicating whether the rest modes except the first mode are adopted when the first bit indicates that the first mode is not adopted, and the third bit is used for indicating whether the image block adopts the second mode or the third mode when the second bit indicates that the rest modes except the first mode are adopted; and the second bit and the third bit are encoded/decoded by adopting mutually independent probability models, so that parallel encoding/decoding is realized, and the encoding/decoding efficiency is improved.

Description

Video image processing method, device and storage medium

Technical Field

The present invention relates to the field of video encoding/decoding, and in particular, to a video image processing method, apparatus, and storage medium.

Background

Currently, in general video coding (Versatile Video Coding), various prediction modes including inter-component linear models (Cross Component Linear Mode, CCLM) are used in chroma prediction to improve the accuracy of chroma component prediction. When the number of the chroma prediction mode of the image block is analyzed using the CCLM prediction mode, there is a dependency relationship in bit analysis at different positions, for example, the encoding/decoding method of the bit at the fourth position of the image block needs to refer to the value of the bit at the third position. This approach results in higher encoding/decoding complexity and lower encoding/decoding efficiency. Therefore, how to better improve the coding/decoding efficiency is an important point of research.

Disclosure of Invention

The embodiment of the invention provides a video image processing method, video image processing equipment and a storage medium, which realize parallel encoding/decoding, reduce the complexity of encoding/decoding process, save encoding/decoding time and improve encoding/decoding efficiency.

In a first aspect, an embodiment of the present invention provides a video image processing method, including:

binarizing a chrominance prediction mode of an image block of an image to be encoded/decoded to obtain a bit string, wherein the bit string comprises at least three adjacent bits, the image to be encoded/decoded allows the use of an inter-component linear model CCLM and/or a conventional intra-frame chrominance prediction mode, the CCLM at least comprises a first mode, a second mode and a third mode, and the conventional intra-frame chrominance prediction mode is other intra-frame chrominance prediction modes except the CCLM;

Wherein a first bit of the three adjacent bits is used for indicating whether a first mode of the CCLM is adopted, a second bit is used for indicating whether the rest modes of the CCLM except the first mode are adopted when the first bit indicates that the first mode of the CCLM is not adopted, and a third bit is used for indicating whether the second mode or the third mode of the CCLM is adopted when the second bit indicates that the rest modes of the CCLM except the first mode are adopted;

and respectively encoding/decoding the second bit and the third bit by adopting mutually independent probability models.

In a second aspect, an embodiment of the present invention provides a video image processing apparatus, including: a memory and a processor;

the memory is used for storing program instructions;

the processor is configured to invoke the program instructions, which when executed, are configured to:

In a third aspect, an embodiment of the present invention provides a computer-readable storage medium storing a computer program which, when executed by a processor, implements the video image processing method according to the first aspect described above.

According to the embodiment of the invention, the bit string is obtained by binarizing the chromaticity prediction mode of the image block of the image to be encoded/decoded, the bit string comprises at least three adjacent bit positions, and the second bit position and the third bit position in the bit string are encoded/decoded respectively by adopting mutually independent probability models, so that parallel encoding/decoding is realized, encoding/decoding complexity is reduced, and encoding/decoding efficiency is improved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1a is a schematic diagram of a CCLM according to an embodiment of the present invention;

FIG. 1b is a schematic diagram of another CCLM provided by an embodiment of the present invention;

fig. 2 is a schematic flow chart of a video image processing method according to an embodiment of the present invention;

fig. 3 is a schematic structural view of a video image processing apparatus according to an embodiment of the present invention;

fig. 4 is a schematic diagram of an arithmetic coding process according to an embodiment of the present invention.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

Some embodiments of the present invention are described in detail below with reference to the accompanying drawings. The following embodiments and features of the embodiments may be combined with each other without conflict.

The video image processing method provided by the embodiment of the invention can be applied to video image processing equipment, and the video processing equipment can be arranged on an intelligent terminal (such as a mobile phone, a tablet personal computer and the like). In some embodiments, the embodiments of the present invention may be applied to an aircraft (e.g., an unmanned aerial vehicle), and in other embodiments, the embodiments of the present invention may also be applied to other movable platforms (e.g., an unmanned ship, an unmanned vehicle, a robot, etc.), which are not particularly limited.

The video image processing method provided by the embodiment of the invention is mainly applied to the coder/decoder which accords with the international video coding standard H.264, the video compression standard (High Efficiency Video Coding, HEVC), the VVC and the China video coding/decoding standard (Audio Video coding Standard, AVS), the AVS+, the AVS2, the AVS3 and the like. Prior to describing embodiments of the present invention, a chroma prediction technique in a video coding standard is described.

The input of video coding is a video sequence in YUV format, wherein Y is a luminance component and U, V is a chrominance component, and in a new generation of video coding standard VVC, a CCLM mode is introduced, so as to improve accuracy of chrominance component prediction.

Referring to fig. 1a and 1b, a schematic diagram of a CCLM according to an embodiment of the present invention is illustrated in fig. 1a, and a schematic diagram of another CCLM according to an embodiment of the present invention is illustrated in fig. 1 b. Fig. 1a shows a current chroma block, and fig. 1b shows a chroma prediction block obtained based on the current chroma block of fig. 1 a. Because of the strong correlation between the different components of the video sequence, the coding performance can be improved by utilizing the correlation between the different components of the video sequence. Therefore, in order to reduce the inter-component redundancy information, in the CCLM prediction mode, the chrominance components are predicted based on the reconstructed luminance component in the same block, using the following linear model:

pred _C (i，j)＝α·rec′ _L (i，j)+β

wherein pred _C Refers to the chroma prediction block, rec' _L Referring to the downsampled luminance component of the co-located luminance coding block, the parameters α and β are derived by minimizing the regression error between neighboring reconstructed luminance and chrominance samples, as shown in equations (1) and (2) below:

where L (n) represents the reconstructed luma samples downsampled for the left and upper adjacent columns and for the upper adjacent rows, and C (n) represents the reconstructed chroma samples left and upper adjacent to the current chroma block. The α and β do not need to be transmitted and are calculated in the same way in the decoder.

It should be noted that prediction is an important module of the main stream video coding framework, and intra prediction uses already reconstructed neighboring pixels to obtain a prediction block in different prediction modes. The prediction modes used for the luma and chroma components are in addition to the traditional Planar mode, DC mode, 65 angle modes, and the chroma prediction mode also introduces a new CCLM mode. For a frame of image, it is first divided into Coding Tree Units (CTUs) of the same size, for example 64x64, 128x128 sizes. Each CTU may be further divided into square or rectangular Coding Units (CUs). In CTUs of intra-coded frame I frames, the luminance component and the chrominance component may have different partitioning schemes; in the bi-predictive interpolation encoded frame B frame and the forward predictive encoded frame P frame, the luminance component and the chrominance component have the same division. The chroma prediction mode numbers of the image blocks are transmitted in the bitstream.

Currently, intra prediction techniques in mainstream video coding standards mainly include Planar mode, DC mode, and 65 angle modes, and in addition, chroma prediction mode additionally includes CCLM mode. CCLM modes may include a variety of types including, for example: at least one of three prediction modes of lt_cclm, t_cclm, and l_cclm. The number of chroma prediction modes is transmitted in the code stream. To save coding complexity, in one example, there are 5 or 8 chroma prediction modes, respectively, depending on whether the CCLM mode is on.

When the CCLM mode is off, there are 5 chroma prediction modes, and the 5 chroma prediction modes correspond to the following table 1, respectively. As shown in table 1, the chroma prediction mode when the CCLM is turned off is shown, wherein, for the luminance mode, no. 0 is Planar mode, no. 1 is DC mode, no. 50 is angular Vertical mode, and No. 18 is angular horizontal mode.

In some embodiments, the number of the chroma prediction mode may look up the number of the chroma prediction mode corresponding to the luma mode through table 1 according to the luma mode.

Taking table 1 as an example for illustrating how to query the luminance pattern using table 1, when the CCLM pattern is turned off, if the luminance pattern is Planar pattern No. 0 and the chroma prediction pattern number is No. 1, it can be determined from table 1 that the luminance pattern corresponding to the luminance pattern No. 0 and the chroma prediction pattern number 1 is the angle Vertical pattern No. 50 in the second column of the third row. For another example, when the CCLM mode is turned off, if the luminance mode is the 18-degree horizons mode and the chroma prediction mode number is No. 3, it may be determined from table 1 that the luminance mode corresponding to the chroma prediction mode number 3 in the luminance mode 18 is the DC mode number 1 in the third column of the fifth row.

TABLE 1

A bit string is obtained by binarizing a chroma prediction mode of an image block so as to encode/decode bits in the bit string. When the CCLM is off, the manner of binarizing the chroma prediction mode shown in table 1 is shown in table 2 below, wherein mode No. 4 is the chroma DM mode.

TABLE 2

Chroma prediction mode numbering	Binarization
		4	0
0	100
		1	101
2	110
		3	111

When the CCLM mode is closed, after the chroma prediction mode is binarized, bits at the first position of the bit string are encoded by using a context number 0, and bits at the second position and the third position of the bit string are both in an equal probability bypass mode. At this time, there is no dependency on bits encoding different positions of the chroma prediction mode numbers.

When the CCLM mode is turned on, there are 8 chroma prediction modes, and the 8 chroma prediction modes respectively correspond to the following table 3, wherein, the 4, 5, 6 chroma prediction modes respectively correspond to the LTCCLM, l_cclm, t_cclm modes, the 7 is the DM mode, and the 0, 1, 2, 3 are other modes or the normal intra chroma prediction modes.

TABLE 3 Table 3

Taking table 3 as an example for explaining how to query the luminance pattern using table 3, when the CCLM pattern is turned on, if the luminance pattern is Planar pattern No. 0 and the chroma prediction pattern number is l_cclm pattern No. 5, it can be determined from table 3 that the luminance pattern corresponding to the luminance pattern No. 0 and the chroma prediction pattern number 5 is pattern No. 82 in the second column of the seventh row. For another example, when the CCLM mode is turned on, if the luminance mode is the 18-degree horizons mode and the chroma prediction mode number is the DM mode number 7, it may be determined from table 3 that the luminance mode corresponding to the chroma prediction mode number 8 in the luminance mode 18 is the 18-degree horizons mode in the fourth column of the ninth row.

When the CCLM is turned on, the manner of binarizing the chroma prediction modes shown in table 3 is as shown in table 4 below.

TABLE 4 Table 4

Chroma prediction mode numbering	Binarization
		7	0
4	10
		5	1110
6	1111
		0	11000
1	11001
		2	11010
3	11011

When transmitting in the code stream, according to whether the CCLM mode is opened or not, the number of the chroma prediction mode has different value ranges, and the bit string after binarization is transmitted in the code stream after being encoded.

As shown in table 4, the bit at the first position in the bit string is used to indicate whether DM mode or other modes are used, including but not limited to CCLM mode or normal intra chroma prediction mode. For example, if the bit string binarized by the chroma prediction mode number 7 is 0 and the bit at the first position is 0, determining to adopt the DM mode; for example, if the bit string binarized by the chroma prediction mode number 4 is 10 and the bit at the first position is 1, it is determined to use a mode other than the DM mode.

The second bit is used to indicate whether the LT CCLM mode is used, for example, if the bit string binarized by the chroma prediction mode number 4 is 10 and the second bit is 0, it is determined that the LT CCLM mode is used.

The bits of the third position are used for indicating that other modes than the LT CCLM mode are adopted when the bits of the second position indicate that the LT CCLM mode is not adopted, for example, the bits of the third position of the binarized bit string of the chroma prediction mode numbers 5, 6, 0, 1, 2, 3 are used for indicating that other modes than the LT CCLM mode are adopted. The bit at the fourth position is used for indicating that the L CCLM mode or the T CCLM mode is adopted when the bit at the third position is 1, the bit string binarized by the chroma prediction mode number 5 is 1110, and the bit at the fourth position is 0, so that the L CCLM mode can be determined to be adopted; when the bit string binarized by the chroma prediction mode number 6 is 1111 and the bit at the fourth position is 1, it can be determined that the T CCLM mode is adopted.

When the bit of the third position is 0, the bit of the fourth position and the bit of the fifth position are used to indicate the number of the employed chroma prediction mode. For example, the bit string binarized for the chroma prediction mode number 0 is 11000, the bit string binarized for the chroma prediction mode number 1 is 11001, the bit string binarized for the chroma prediction mode number 2 is 11010, and the bit string binarized for the chroma prediction mode number 3 is 11 011.

In some embodiments, the bit string may be a 1-bit string, taking table 4 as an example, if the bit string corresponding to the binarized chroma prediction mode number 7 is 0, it may be determined that the DM mode is used in the chroma prediction mode number 7.

In some embodiments, the bit string may include 2 adjacent bits, taking table 4 as an example, assuming that the video image processing apparatus binarizes the chroma prediction mode number 4 of the image block of the image to be encoded/decoded to obtain a bit string of 10, and the bit at the first position is 1, it may be determined that the chroma prediction mode of the image block does not use the DM mode, that is, other modes than the DM mode, may use the CCLM mode or the normal intra chroma prediction mode, and the bit at the second position is 0, and it may be determined that the chroma prediction mode of the image block uses the LT CCLM mode of the CCLM modes.

When the CCLM mode is on, the chroma prediction mode is raised from 5 to 8. At this time, the bits of the first position, the bits of the second position, and the bits of the third position of the bit string are encoded using contexts of No. 0, no. 1, and No. 2, respectively. When the bits of the fourth position are encoded, the encoding mode needs to be determined according to the value of the bits of the third position. When the value of the bit of the third position is equal to 0, the bit of the fourth position and the bit of the fifth position are coded by bypass; when the value of the bit of the third position is equal to 1, the bit of the fourth position is encoded using context number 2. At this time, the decoding process needs to determine the value of the bit at the third position to further decode the bit at the fourth position.

In some embodiments, the coding process of the chroma prediction mode numbers is as follows in table 5:

TABLE 5

Where na is used to indicate a null coding model and bypass is used to indicate a corresponding bypass coding mode hereinafter.

As shown in table 5, the bits Idx include 0, 1, 2, 3, and 4, wherein 0 is a bit indicating a first position, 2 is a bit indicating a second position, i.e., a first bit, 2 is a bit indicating a third position, i.e., a second bit, 3 is a bit indicating a fourth position, i.e., a third bit, and 4 is a bit indicating a fourth position, i.e., a third bit.

As can be seen from the implementation details of the coded chroma prediction mode numbers shown in table 5, when the CCLM mode is turned on, the process of parsing the bits at the fourth position needs to depend on the values of the bits at the third position. If the value of the bit at the third position is equal to 0, the encoding of the bit at the fourth position uses bypass encoding; if the value of the bit at the third position is equal to 1, the bit at the fourth position is encoded in a manner using context-based binary arithmetic coding. Therefore, it can be determined that the value of the bit at the fourth position depends on the value of the bit at the third position, so that there is coupling between the bit at the fourth position and the bit at the third position, which is complicated and has low encoding/decoding efficiency.

Therefore, the embodiment of the present invention proposes binarizing a chroma prediction mode of an image block of an image to be encoded/decoded to obtain a bit string, where the bit string includes at least three adjacent bits, and the image to be encoded/decoded allows to use an inter-component linear model CCLM and/or a conventional intra-chroma prediction mode, where the CCLM includes at least a first mode, a second mode, and a third mode, and the conventional intra-chroma prediction mode is other intra-chroma prediction modes except for the CCLM. And when the second bit indicates that the rest modes of the CCLM except the first mode are adopted, the second bit indicates that the second bit and the third bit are respectively coded/decoded by adopting mutually independent probability models.

The embodiment of the invention can effectively reduce the complexity of hardware analysis while keeping performance gain caused by various chroma prediction modes, and can improve the parallelism of hardware analysis without obvious coding/decoding performance loss, remove coding/decoding dependence of bits at different positions, simplify the complexity of each bit during coding/decoding and improve the coding/decoding efficiency for the improved method aiming at the chroma mode coding/decoding mode.

The video image processing method provided by the embodiment of the invention is schematically described below with reference to the accompanying drawings.

Referring to fig. 2 specifically, fig. 2 is a flow chart of a video image processing method according to an embodiment of the invention. The method may be applied to a video image processing apparatus, wherein the explanation of the video image processing apparatus is as described above and will not be repeated here. Specifically, the method of the embodiment of the invention comprises the following steps.

S201: binarizing a chroma prediction mode of an image block of an image to be encoded/decoded to obtain a bit string, wherein the bit string comprises at least three adjacent bits, the image to be encoded/decoded allows an inter-component linear model CCLM and/or a conventional intra-frame chroma prediction mode to be used, the CCLM at least comprises a first mode, a second mode and a third mode, and the conventional intra-frame chroma prediction mode is other intra-frame chroma prediction modes except the CCLM.

In an embodiment of the present invention, the video image processing apparatus may binarize a chroma prediction mode of an image block of an image to be encoded/decoded to obtain a bit string, where the bit string includes at least three adjacent bits, and the image to be encoded/decoded allows use of an inter-component linear model CCLM and/or a conventional intra-frame chroma prediction mode, where the CCLM includes at least a first mode, a second mode, and a third mode, and the conventional intra-frame chroma prediction mode is other intra-frame chroma prediction modes except for the CCLM.

In some embodiments, a first bit of the three adjacent bits is used to indicate whether a first mode of the CCLM is employed, a second bit is used to indicate whether the rest of the CCLM except the first mode is employed when the first bit indicates that the first mode of the CCLM is not employed, and a third bit is used to indicate whether the second mode or the third mode of the CCLM is employed by the image block when the second bit indicates that the rest of the CCLM except the first mode is employed.

In some embodiments, the first bit is a bit at a second position in the bit string, the second bit is a bit at a third position in the bit string, and the third bit is a bit at a fourth position in the bit string. Taking the bit string 1110 binarized with the chroma prediction mode number 5 in table 4 as an example, three adjacent bits are illustrated, wherein the first bit in the bit string 1110 is 1 at the second position, the second bit is 1 at the third position, and the third bit is 0 at the fourth position.

In one embodiment, the third bit is further for indicating to employ one of the regular intra chroma prediction modes when the second bit indicates not to employ the rest of the CCLM modes other than the first mode. In certain embodiments, the conventional intra chroma prediction modes include any one or more of Planar mode, DC mode, 65 angle modes.

In some embodiments, the first mode comprises an lt_cclm mode, the second mode comprises an l_cclm mode, and the third mode comprises a t_cclm mode. In certain embodiments, the CCLM mode is an intra-predicted chroma prediction mode. Taking table 4 as an example for illustration, bit string 10 binarized by chroma prediction mode number 4 corresponds to a first mode, lt_cclm mode, bit string 1110 binarized by chroma prediction mode number 5 corresponds to a second mode, l_cclm mode, and bit string 1111 binarized by chroma prediction mode number 6 corresponds to a third mode, t_cclm mode.

In some embodiments, the first mode, the second mode, and the third mode may be modes other than lt_cclm mode, l_cclm mode, and t_cclm mode.

In some embodiments, the image blocks in the image to be encoded/decoded are square and/or rectangular.

In some embodiments, the bits in the bit string may be represented in the form of "bin" in arithmetic encoding/decoding, although in other embodiments, the bits may be represented in other forms, which are not specifically limited herein.

In some embodiments, the image to be encoded/decoded is an image to be encoded/decoded with the CCLM turned on. In some embodiments, the image to be encoded/decoded includes at least one image block with a CCLM in an on state.

In some embodiments, whether the CCLM is in an on state may be determined by an identification added at the time of encoding. In some embodiments, when encoding the picture to be encoded, an identification may be added in a video parameter set (Video Parameter Set, VPS), a sequence parameter set (Sequence Parameter Set, SPS), a picture parameter set (Picture Parameter Set, PPS), a sequence header, a slice header, or a picture header, the identification indicating whether the picture or picture block to be encoded allows CCLM to be used. Different values of the identification represent different situations. For example, if the identification is a second value (e.g., 1), it indicates that CCLM is allowed to be used, and if the identification is a first value (e.g., 0), it indicates that CCLM is not allowed. In some embodiments, when decoding an image to be decoded, it may be determined whether the image to be decoded or the image block is allowed to use the CCLM according to the decoded identification; the decoded identity may be present in VPS, SPS, PPS, sequence header, slice header or picture header, among others. For example, if the decoded identity exists in the VPS and is identified as a second value (e.g., 1), it indicates that CCLM is allowed to be used, and if the decoded identity is identified as a first value (e.g., 0), it indicates that CCLM is not allowed.

In some embodiments, the allowed use CCLM has the same meaning as the CCLM in the on state, i.e., if it is determined that the CCLM is in the on state, it may be determined that the image to be encoded/decoded is allowed to use the CCLM.

In some embodiments, the image to be encoded/decoded includes at least one image block with a CCLM in an on state and at least one image block with a CCLM in an off state, and for all the image blocks in the image to be encoded/decoded, the second bit and the third bit of the image block are encoded/decoded by using probability models that are independent of each other.

In some embodiments, when the first bit is used to indicate a first mode of the CCLM and the second bit is a first value, the second bit is used to indicate that a conventional intra chroma prediction mode is employed. In certain embodiments, the first value is 0.

In one embodiment, when the first bit is used to indicate the first mode and the second bit meets a second value, the second bit is used to indicate a second mode or a third mode in which the CCLM is employed.

In one embodiment, when the second bit is used to indicate that the second mode or the third mode of the CCLM is employed and the third bit meets the first value, the third bit is used to indicate that the second mode of the CCLM is employed.

In one embodiment, when the second bit is used to indicate that the second mode or the third mode of the CCLM is employed and the third bit meets a second value, the third bit is used to indicate that the third mode of the CCLM is employed. In certain embodiments, the second value is 1.

Taking table 4 as an example, assuming that the first value is 0 and the second value is 1, if the video image processing apparatus binarizes a chroma prediction mode of an image block of an image to be encoded/decoded to obtain a bit string of 1110, and the bit at the first position is 1, it may be determined that the chroma prediction mode of the image block is a CCLM mode or a normal intra chroma prediction mode; the bit of the second position is 1, and it may be determined that the chroma prediction mode of the image block is the lt_cclm mode among the unused CCLM modes; the third position bit is 1, and it may be determined that the chroma prediction mode of the image block uses an l_cclm mode or a t_cclm mode. The fourth bit is 0, it may be determined that the chroma prediction mode of the image block uses the l_cclm mode.

For example, if the video image processing apparatus binarizes a chroma prediction mode of an image block of an image to be encoded/decoded to obtain a bit string 1111, and the bit of the first position is 1, it may be determined that the chroma prediction mode of the image block is a CCLM mode or a normal intra chroma prediction mode; the bit of the second position is 1, and it may be determined that the chroma prediction mode of the image block is the lt_cclm mode among the unused CCLM modes; the third position bit is 1, and it may be determined that the chroma prediction mode of the image block uses an l_cclm mode or a t_cclm mode. The fourth bit is 1, and it may be determined that the chroma prediction mode of the image block uses the t_cclm mode.

In one embodiment, when the second bit is used to indicate that a normal intra chroma prediction mode is employed, the last two bits adjacent to the second bit are used to indicate the number of the normal intra chroma prediction mode. In some embodiments, if the bit string includes four adjacent bits, it may be determined that the image block uses a conventional intra chroma prediction mode.

For example, if the video image processing apparatus binarizes a chroma prediction mode of an image block of an image to be encoded/decoded to obtain a bit string of 11000, and the bit of the first position is 1, it may be determined that the chroma prediction mode of the image block is a CCLM mode or a normal intra chroma prediction mode; the bit of the second position is 1, and it may be determined that the chroma prediction mode of the image block is the LT CCLM mode among the unused CCLM modes; the bit of the third position is 0, it can be determined that the chroma prediction mode of the image block uses a conventional intra chroma prediction mode; the bits of the fourth position and the fifth position are 00, the number 0 of the normal intra chroma prediction mode may be determined.

For another example, if the video image processing apparatus binarizes a chroma prediction mode of an image block of an image to be encoded/decoded to obtain a bit string of 11001, and the bit of the first position is 1, it may be determined that the chroma prediction mode of the image block is a CCLM mode or a normal intra chroma prediction mode; the bit of the second position is 1, and it may be determined that the chroma prediction mode of the image block is the LT CCLM mode among the unused CCLM modes; the bit of the third position is 0, it can be determined that the chroma prediction mode of the image block uses a conventional intra chroma prediction mode; the bit of the fourth position and the bit of the fifth position are 01, the number 1 of the normal intra chroma prediction mode may be determined.

Similarly, if the video image processing apparatus binarizes the chroma prediction mode of an image block of an image to be encoded/decoded to obtain a bit string of 11010, and the bit of the first position is 1, it may be determined that the chroma prediction mode of the image block is a CCLM mode or a normal intra chroma prediction mode; the bit of the second position is 1, and it may be determined that the chroma prediction mode of the image block is the lt_cclm mode among the unused CCLM modes; the bit of the third position is 0, it can be determined that the chroma prediction mode of the image block uses a conventional intra chroma prediction mode; the bit at the fourth position and the bit at the fifth position are 10, the number 2 of the normal intra chroma prediction mode may be determined.

Similarly, if the video image processing apparatus binarizes the chroma prediction mode of an image block of an image to be encoded/decoded to obtain a bit string of 11011, and the bit of the first position is 1, it may be determined that the chroma prediction mode of the image block is a CCLM mode or a normal intra chroma prediction mode; the bit of the second position is 1, and it may be determined that the chroma prediction mode of the image block is the lt_cclm mode among the unused CCLM modes; the bit of the third position is 0, it can be determined that the chroma prediction mode of the image block uses a conventional intra chroma prediction mode; the bit at the fourth position and the bit at the fifth position are 11, the number 3 of the normal intra chroma prediction mode may be determined.

S202: and respectively encoding/decoding the second bit and the third bit by adopting mutually independent probability models.

In the embodiment of the invention, the video image processing device can adopt mutually independent probability models to encode/decode the second bit and the third bit respectively.

In some embodiments, the mutually independent probability models refer to modes that are encoded using independent contexts, i.e., conventional coding modes. Specifically, the bypass coding mode and the normal coding mode will be illustrated by taking fig. 4 as an example, and fig. 4 is a schematic diagram of an arithmetic coding process according to an embodiment of the present invention. As shown in fig. 4, firstly, binarizing is performed on an input syntax element with a non-binary value, a binary bit string generated by the binarization is then subjected to an encoding stage, when a conventional encoding mode is selected, the bit string enters context modeling, after a context model is determined, the bit string and a corresponding context model are sent to a conventional encoding module together for encoding, then, an encoding result is output, and the context model is updated according to the encoding result.

In one embodiment, when the video image processing apparatus encodes/decodes the second bit and the third bit respectively using mutually independent probability models, a new context may be added to the third bit of the image block, and the next bit adjacent to the third bit may be encoded/decoded using bypass mode.

In some embodiments, the bypass mode is a corresponding bypass coding mode hereinafter. The bypass coding mode can be specifically illustrated by way of example in fig. 4. As shown in fig. 4, firstly, binarizing the syntax elements of the input non-binary values, then entering the encoding stage, and when the bypass encoding mode is selected, considering 0 and 1 in the binary bit string as equal probability distribution, sending to the bypass encoding module for encoding, and then outputting the encoding result. The mode can reduce the complexity of implementation and accelerate the encoding and decoding processes.

For example, the video image processing apparatus may add a context number 1 to the third bit of the image block for encoding/decoding; alternatively, bypass mode may be used to encode/decode the next bit adjacent to the third bit.

Therefore, the implementation mode can determine the encoding/decoding modes of the third bit and the next adjacent bit to be independent of each other, so that the encoding/decoding dependence among the bits in different positions is removed, the complexity of encoding/decoding of each bit is simplified, and the encoding/decoding efficiency is improved.

In one embodiment, the video image processing apparatus may add a new context to the third bit of the image block and add a new context to a next bit adjacent to the third bit when encoding/decoding the second bit and the third bit, respectively, using mutually independent probability models.

For example, the video image processing apparatus may add a context number 2 to a third bit of the image block for encoding/decoding, and add a context number 0 to a next bit adjacent to the third bit for encoding/decoding.

In one embodiment, the video image processing apparatus adopts bypass mode when encoding/decoding the second bit and the third bit respectively using mutually independent probability models; optionally, a new context may also be added to the next bit adjacent to the third bit.

For example, the video image processing apparatus may encode/decode a third bit of the image block in bypass mode and add a context number 0 to a next bit adjacent to the third bit.

In one embodiment, the video image processing apparatus encodes/decodes the second bit and the third bit using the same context as the second bit when the second bit and the third bit are encoded/decoded using mutually independent probability models, respectively.

Therefore, the implementation mode can determine the encoding/decoding modes of the third bit and the second bit to be independent of each other, so that the encoding/decoding dependency between the third bit and the second bit is removed, the complexity of encoding/decoding of each bit is simplified, and the encoding/decoding efficiency is improved.

For example, if the video image processing apparatus uses the context number 1 to encode/decode the second bit, the third bit of the image block may be encoded/decoded using the same context number 1 as the second bit.

In the embodiment of the invention, the video image processing device can binarize the chroma prediction mode of the image block of the image to be encoded/decoded to obtain the bit string, the bit string comprises at least three adjacent bit bits, and the second bit and the third bit in the bit string are encoded/decoded respectively by adopting the mutually independent probability model.

Referring to fig. 3, fig. 3 is a schematic structural diagram of a video image processing apparatus according to an embodiment of the present invention, and specifically, the video image processing apparatus includes: memory 301, processor 302, and data interface 303.

The memory 301 may include volatile memory (volatile memory); memory 301 may also include non-volatile memory (nonvolatile memory); memory 301 may also include a combination of the above types of memory. The processor 302 may be a central processing unit (central processing unit, CPU). The processor 302 may further comprise a hardware video image processing device. The hardware video image processing device described above may be an application-specific integrated circuit (ASIC), a programmable logic device (programmable logic device, PLD), or a combination thereof. Specifically, for example, a complex programmable logic device (complex programmable logic device, CPLD), a field-programmable gate array (field-programmable gate array, FPGA), or any combination thereof may be used.

Further, the memory 301 is configured to store program instructions, and the processor 302 may invoke the program instructions stored in the memory 301 when the program instructions are executed, for performing the following steps:

Further, the third bit is further for indicating to employ one of the regular intra chroma prediction modes when the second bit indicates not to employ the remaining modes of the CCLM other than the first mode.

Further, the image to be encoded/decoded includes at least one image block in which the CCLM is in an on state.

Further, the image to be encoded/decoded comprises at least one image block with CCLM in an open state and at least one image block with CCLM in a closed state;

and for all image blocks in the image to be encoded/decoded, encoding/decoding the second bit and the third bit of the image block by adopting mutually independent probability models.

Further, when the value of the first bit satisfies a first value, the first bit is used to indicate a first mode using the CCLM.

Further, when the first bit is used to indicate a first mode of the CCLM and the second bit satisfies a first value, the second bit is used to indicate that a conventional intra chroma prediction mode is employed.

Further, the first value is 0.

Further, when the first bit is used to indicate the first mode and the second bit meets a second value, the second bit is used to indicate a second mode or a third mode using the CCLM.

Further, when the second bit is used to indicate that the second mode or the third mode of the CCLM is adopted and the third bit satisfies the first value, the third bit is used to indicate that the second mode of the CCLM is adopted.

Further, when the second bit is used to indicate that the second mode or the third mode of the CCLM is adopted and the third bit satisfies a second value, the third bit is used to indicate that the third mode of the CCLM is adopted.

The method of claim 10, wherein the second value is 1.

Further, when the second bit is used to indicate that a normal intra chroma prediction mode is employed, the last two bits adjacent to the second bit are used to indicate the number of the normal intra chroma prediction mode.

Further, when the processor 302 uses the mutually independent probability models to encode/decode the second bit and the third bit respectively, the method is specifically used for:

the third bit of the image block is encoded/decoded using bypass mode.

adding a new context to the third bit of the image block and encoding/decoding a next bit adjacent to the third bit using bypass mode.

adding a new context to the third bit of the image block and adding a new context to the next bit adjacent to the third bit.

the third bit of the image block is in bypass mode and a new context is added to the next bit adjacent to the third bit for encoding/decoding.

the third bit of the image block is encoded/decoded using the same context as the second bit.

Further, the first mode includes an lt_cclm mode;

the second mode includes an l_cclm mode;

the third mode includes a t_cclm mode.

Further, the CCLM mode is a chroma prediction mode of intra prediction.

Further, the image blocks in the image to be encoded/decoded are square and/or rectangular.

Further, the first bit is a bit at a second position in the bit string;

the second bit is the bit of the third position in the bit string;

the third bit is a bit at a fourth position in the bit string.

Further, the conventional intra chroma prediction modes include any one or more of Planar mode, DC mode, 65 angle modes.

In the embodiment of the present invention, a computer readable storage medium is further provided, where the computer readable storage medium stores a computer program, where the computer program when executed by a processor implements the video image processing method described in fig. 2 of the embodiment of the present invention, and may also implement the video image processing apparatus of the corresponding embodiment of the present invention described in fig. 3, which is not described herein again.

The computer readable storage medium may be an internal storage unit of the device according to any of the foregoing embodiments, for example, a hard disk or a memory of the device. The computer readable storage medium may also be an external storage device of the device, such as a plug-in hard disk, a Smart Media Card (SMC), a Secure Digital (SD) Card, a Flash memory Card (Flash Card) or the like, which are provided on the device. Further, the computer readable storage medium may also include both internal storage units and external storage devices of the device. The computer-readable storage medium is used to store the computer program and other programs and data required by the device. The computer-readable storage medium may also be used to temporarily store data that has been output or is to be output.

Those skilled in the art will appreciate that implementing all or part of the above-described methods in accordance with the embodiments may be accomplished by way of a computer program stored on a computer readable storage medium, which when executed may comprise the steps of the embodiments of the methods described above. The storage medium may be a magnetic disk, an optical disk, a Read-Only Memory (ROM), a random access Memory (Random Access Memory, RAM), or the like.

The above disclosure is illustrative only of some embodiments of the invention and is not intended to limit the scope of the invention, which is defined by the claims and their equivalents.

Claims

1. A video image processing method, comprising:

when the second bit is used for indicating to adopt a second mode or a third mode of the CCLM and the third bit meets different values, the third bit is used for indicating to adopt the second mode of the CCLM or the third mode of the CCLM;

2. The method of claim 1, wherein the step of determining the position of the substrate comprises,

the image to be encoded/decoded comprises at least one CCLM in an on state.

3. The method of claim 1, wherein the step of determining the position of the substrate comprises,

the image to be encoded/decoded comprises at least one CCLM (CCL graphics context information management) in an on state and at least one CCLM in an off state;

4. The method of claim 1, wherein the second value is 1.

5. The method of claim 1, wherein the encoding/decoding the second bit and the third bit using mutually independent probability models, respectively, comprises:

6. The method of claim 1, wherein the encoding/decoding the second bit and the third bit using mutually independent probability models, respectively, comprises:

7. The method of claim 1, wherein the encoding/decoding the second bit and the third bit using mutually independent probability models, respectively, comprises:

8. The method of claim 1, wherein the encoding/decoding the second bit and the third bit using mutually independent probability models, respectively, comprises:

9. The method of claim 1, wherein the step of determining the position of the substrate comprises,

the first mode includes an lt_cclm mode;

the second mode includes an l_cclm mode;

the third mode includes a t_cclm mode.

10. The method of claim 1, wherein the step of determining the position of the substrate comprises,

The CCLM mode is a chroma prediction mode of intra prediction.

11. The method of claim 1, wherein the step of determining the position of the substrate comprises,

the image blocks in the image to be encoded/decoded are square and/or rectangular.

12. The method of claim 1, wherein the step of determining the position of the substrate comprises,

the conventional intra chroma prediction mode includes any one or more of Planar mode, DC mode, 65 angle modes.

13. A video image processing apparatus comprising a memory and a processor;

the memory is used for storing program instructions;

14. A computer readable storage medium for storing a bit stream, wherein the bit stream is formed by a computer program, wherein the computer program is executed by a processor to implement:

binarizing a chrominance prediction mode of an image block of an image to be encoded to obtain a bit string, wherein the bit string comprises at least three adjacent bits, the image to be encoded allows to use an inter-component linear model CCLM and/or a conventional intra-frame chrominance prediction mode, the CCLM at least comprises a first mode, a second mode and a third mode, and the conventional intra-frame chrominance prediction mode is other intra-frame chrominance prediction modes except the CCLM;

and respectively encoding the second bit and the third bit by adopting mutually independent probability models.

15. A method for generating a code stream, comprising:

binarizing a chrominance prediction mode of an image block of an image to be coded to obtain a bit string, wherein the bit string comprises at least three adjacent bits, the image to be coded/decoded allows an inter-component linear model CCLM and/or a conventional intra-frame chrominance prediction mode to be used, the CCLM at least comprises a first mode, a second mode and a third mode, and the conventional intra-frame chrominance prediction mode is other intra-frame chrominance prediction modes except the CCLM;

the second bit and the third bit are encoded using mutually independent probability models, respectively, to generate a bit stream.

16. A video image processing apparatus comprising a memory and a processor;

the memory is used for storing program instructions;