Video decoding method and apparatus for predicting chroma component residual data using chroma component

Abstract

The present application provides a data compression method and device which adaptively uses inter-component prediction of original data and / or inter-component prediction of residual data at the level of a coding block. First, a prediction operation is performed on the coding block using a prediction mode including an inter-component prediction mode of original data, to eliminate the correlation between the original values of the components to some extent; then, the residual data generated after the prediction of the coding block is further used for inter-component prediction of residual data to eliminate the correlation between the residual values of the components.

Description

[0001] This application is a divisional application of the following original application:

[0002] Original application filing date: 2019-12-30

[0003] Original application number: 2019114058551

[0004] Original application invention name: Data compression method and apparatus using inter-component prediction of original and residual data TECHNICAL FIELD

[0005] The present invention relates to an encoding and decoding system for lossy or lossless compression of data, in particular a method and apparatus for encoding and decoding of multi-component data such as color image and video data. BACKGROUND

[0006] With the human society entering the era of big data, cloud computing, mobile computing, cloud-mobile computing, ultra-high definition (4K) and super ultra-high definition (8K) video image resolution, 4G / 5G communication, virtual reality, it is necessary to compress various data, including big data, image data, video data, at an ultra-high compression ratio and extremely high quality.

[0007] A data set is a collection of data samples, also called data elements (e.g. bytes, bits, pixels, spatial samples, transform domain coefficients). When encoding (and correspondingly decoding) a data set arranged in a certain spatial (one-dimensional, two-dimensional, or multi-dimensional) shape and having a certain number of elements and a certain sampling format (e.g. a file, a one-dimensional data queue, a two-dimensional data file, an image, a video sequence, a transform domain, a transform block, multiple transform blocks, a three-dimensional scene, a sequence of a continuously changing three-dimensional scene), in particular a two-dimensional or higher data set, the data set is usually divided into a number of sub-sets of blocks having a predetermined shape and size (i.e. number of elements), called coding blocks (from the decoding point of view also called decoding blocks, collectively called coding and decoding blocks), and the encoding or decoding is performed block by block in units of coding and decoding blocks. At any time, the coding block being encoded is called the current coding block. At any time, the decoding block being decoded is called the current decoding block. The current coding block or the current decoding block is collectively called the current coding and decoding block or simply the current block.

[0008] Data elements (short: elements) that are being encoded or decoded are referred to as current encoding data elements or current decoding data elements, collectively as current data elements, short: current elements. Elements consist of K components (typically 1 < K < 5), and thus data sets and coding blocks also consist of K components. For example, elements of a frame of an image, i.e. pixels, are arranged in a rectangular shape with a size (resolution) of 1920 (width) x 1080 (height) and consist of 3 components: G (green) component, B (blue) component, R (red) component or Y (luma) component, U (Cb chroma) component, V (Cr chroma) component.

[0009] Elements or components thereof are collectively referred to as samples. It is generally possible to determine from the context whether a sample refers to an element or a component of an element. If it is not possible to determine from the context whether a sample refers to an element or a component of an element, the sample refers to an element and / or a component of an element.

[0010] Many data sets and coded blocks as the encoding target have a sampling format. For example, for computer-generated images containing graphics and text, a sampling format called 4:4:4 (short for 444) is usually adopted, i.e., the three components of the data set have the same sampling rate and size (i.e., the number of component samples). For natural images and videos captured by a camera, a sampling format called 4:2:0 (short for 420) is usually adopted, i.e., the sampling rate and size of two components (D component and E component) of the data set (e.g., image or video) having a rectangular shape and three components are respectively one fourth of that of the other component (F component). In this case, one D component D[i][j] and one E component E[i][j] correspond to four (2x2) F components F[2i][2j], F[2i+1][2j], F[2i][2j+1], F[2i+1][2j+1]. If the resolution of the F component is 2Mx2N, i.e., the F component of the data set is F = {F[i][j]: i = 0~2M-1, j = 0~2N-1}, then the resolution of the D component and E component is MxN, i.e., the D component and E component of the data set are respectively D = {D[i][j]: i = 0~M-1, j = 0~N-1} and E = {E[i][j]: i = 0~M-1, j = 0~N-1}. In the case where higher video quality is required, a sampling format called 4:2:2 (short for 422) is usually adopted, i.e., the sampling rate and size of two components (D component and E component) of the data set (e.g., image or video) having a rectangular shape and three components are respectively one half of that of the other component (F component). In this case, in one direction (e.g., horizontal direction) of the data set (e.g., image or video), one D component D[i][j] and one E component E[i][j] correspond to two (2x1) F components F[2i][j] and F[2i+1][j]. If the resolution of the F component is 2MxN, i.e., the F component of the data set is F = {F[i][j]: i = 0~2M-1, j = 0~N-1}, then the resolution of the D component and E component is MxN, i.e., the D component and E component of the data set are respectively D = {D[i][j]: i = 0~M-1, j = 0~N-1} and E = {E[i][j]: i = 0~M-1, j = 0~N-1}. In the image and video using YUV color format, the above-mentioned F, D, E components are usually Y, U, V components respectively. In the image and video using RGB color format, the above-mentioned F, D, E components are usually G, B, R components or G, R, B components respectively. In the case where the data is image or video, the sampling format is also called chroma format.

[0011] 444 An image or video in 444 sample format is 2: 1 down-sampled in one direction (e.g. horizontal or vertical) of D and E components to produce 422 sample format, and 2: 1 down-sampled in both horizontal and vertical directions (total 4: 1 down-sampling) of D and E components to produce 420 sample format.

[0012] Generally, there is a certain degree of correlation between different components of multi-component data. Therefore, using a part of components to predict another part of components can effectively play a role of data compression.

[0013] Inter-component prediction can be divided into two types. One is raw data inter-component prediction, i.e. using reconstructed values of raw data of one or several components to construct predicted values of raw values (i.e. values of components themselves) of other components, and performing inter-component prediction on the other components. The other is residual data inter-component prediction, i.e. each component is firstly predicted by itself to obtain residual data (i.e. prediction error of raw data itself) of each component, and then using residual values (i.e. reconstructed values of residual data) of one or several components for calculating reconstructed values of raw data to construct predicted values of residual values (i.e. reconstructed values of residual data) of other components for calculating reconstructed values of raw data, and performing inter-component prediction on residuals of the other components.

[0014] It is particularly noted that, since prediction operation is an operation that can be performed multiple times, the residual of prediction can be predicted again to generate new residual, therefore, raw data and residual data are relative concepts. For one prediction operation, data before prediction operation is called raw data, and prediction difference data obtained after prediction operation is called residual data. Raw data of one prediction operation is allowed to be residual data of another prediction operation. Residual data of one prediction operation is also allowed to be raw data of another prediction operation.

[0015] A reconstructed value of data is reconstructed data obtained after encoding operation and inverse operation thereof, which generally includes prediction and / or transform and / or quantization, are performed on the data. In the case that encoding operation and inverse operation thereof are lossless, the reconstructed value of data is equal to the data itself.

[0016] In principle, under certain conditions, raw data inter-component prediction is equivalent to residual data inter-component prediction. Therefore, the prior art considers that raw data inter-component prediction and residual data inter-component prediction have almost the same effect. Therefore, in the prior art of image and video coding and decoding, either raw data (i.e. pixel data) inter-component prediction is used for pixel data of an entire image or an entire video sequence without using residual data inter-component prediction, or residual data inter-component prediction is used for pixel data of an entire image or an entire video sequence without using raw data (i.e. pixel data) inter-component prediction.

[0017] In the existing image and video coding technology, the pixel data of the image or video in 420 sampling format is coded using original data inter-component prediction, and the pixel data of the image or video in 444 sampling format is coded using residual data inter-component prediction. In the existing image and video coding technology, neither original data inter-component prediction nor residual data inter-component prediction is used when using string prediction (also known as string matching or string copy) coding technology.

[0018] The prior art does not consider that in actual application scenarios, due to the different prediction modes, different transform modes and different quantization factors of each component, the original data inter-component prediction and the residual data inter-component prediction actually have different and complementary effects in some cases, especially in the case of non-444 sampling format, the different and complementary effects are more obvious under certain conditions. SUMMARY

[0019] In order to fully utilize the inter-component correlation to improve the coding efficiency, the present application provides a data compression method and device which adaptively uses original data inter-component prediction and / or residual data inter-component prediction at the coding block level. First, a prediction mode including an original data inter-component prediction mode is used to perform a prediction operation on a coding block, which eliminates the correlation between the original values of each component to a certain extent; then, the residual data inter-component prediction is further used to eliminate the correlation between the residual values of each component for the residual generated after the prediction of the coding block.

[0020] The primary technical feature of the present application is that when coding data having multiple (two or more) components, a part of the coding blocks at least uses original data inter-component prediction, another part of the coding blocks at least uses residual data inter-component prediction, and still another part of the coding blocks at least simultaneously uses original data inter-component prediction and residual data inter-component prediction.

[0021] In the present application, preferably, the compressed data code stream output by the encoder (i.e. the compressed data code stream input by the decoder) at least contains information indicating whether the coding block uses original data inter-component prediction and / or information indicating whether the coding block uses residual data inter-component prediction.

[0022] In the present application, preferably, the data has three components consisting of one primary component and two secondary components; the data of the three components has 444 sampling format or 422 sampling format or 420 sampling format.

[0023] The most basic technical feature of the encoding method or apparatus of the present application is that it comprises at least one step or module of inter-frame prediction encoding and / or string prediction encoding and / or intra-frame prediction encoding including original data component prediction of original data, and at least one step or module of residual data component prediction of residual data generated after the prediction encoding, and the compressed data code stream outputted at least contains information indicating whether the original data component prediction and / or the residual data component prediction is used for the encoding block. Figure 1 (a) is a schematic diagram of the encoding method or apparatus of the present application.

[0024] The most basic technical feature of the decoding method or apparatus of the present application is that it analyzes the compressed data code stream to obtain at least information indicating whether the original data component prediction and / or the residual data component prediction is used for the decoding block; if the information indicates that the original data component prediction is used for the decoding block, the original data prediction value of other components is constructed at least from the original data reconstructed value of one or several components; if the information indicates that the residual data component prediction is used for the decoding block, the prediction value of the residual data reconstructed value of other components for calculating the original data reconstructed value thereof is constructed at least from the residual value (i.e. residual data reconstructed value) of one or several components for calculating the original data reconstructed value thereof. Figure 1 (b) is a schematic diagram of the decoding method or apparatus of the present application.

[0025] According to one aspect of the present application, there is provided an encoding method or apparatus for compressing multi-component data, which comprises at least one or a combination of steps or modules for performing the following functions and operations:

[0026] inter-frame prediction encoding and / or string prediction encoding and / or intra-frame prediction encoding including original data component prediction of original data, the original data component prediction at least comprising prediction value and prediction difference value of Q (Q≥1) components of original data or reconstructed value thereof constructed from at least H (H≥1) components of original data or reconstructed value thereof, wherein the H is allowed to be equal to the Q, part or all of the H components are allowed to overlap with part or all of the Q components, and the prediction difference value of one or more components in the Q components is allowed to be zero;

[0027] performing residual coding on the residual data generated after the prediction coding, the residual data inter-component prediction comprising at least constructing a predicted value and a prediction difference of residual data or its reconstructed value of Z (Z≥1) components from residual data or its reconstructed value of at least W (W≥1) components, wherein W is allowed to be equal to Z, wherein it is allowed that some or all of the W components overlap with some or all of the Z components, and wherein the prediction difference of one or more of the Z components is allowed to be zero;

[0028] writing, into a compressed data bitstream, information indicative of whether the original data inter-component prediction is used and / or whether the residual data inter-component prediction is used.

[0029] From a first aspect, the present application provides an encoding method for compressing multi-component data, characterized by at least one of the following steps or a combination thereof:

[0030] Step 1) performing inter-frame prediction coding and / or serial prediction coding and / or intra-frame prediction coding including original data inter-component prediction on the original data, the original data inter-component prediction comprising at least constructing a predicted value and a prediction difference of original data or its reconstructed value of Q (Q≥1) components from original data or its reconstructed value of at least H (H≥1) components, wherein H is allowed to be equal to Q, wherein it is allowed that some or all of the H components overlap with some or all of the Q components, and wherein the prediction difference of one or more of the Q components is allowed to be zero;

[0031] Step 2) performing residual coding on the residual data generated after the prediction coding, the residual data inter-component prediction comprising at least constructing a predicted value and a prediction difference of residual data or its reconstructed value of Z (Z≥1) components from residual data or its reconstructed value of at least W (W≥1) components, wherein W is allowed to be equal to Z, wherein it is allowed that some or all of the W components overlap with some or all of the Z components, and wherein the prediction difference of one or more of the Z components is allowed to be zero;

[0032] Step 3) writing, into a compressed data bitstream, information indicative of whether the original data inter-component prediction is used and / or whether the residual data inter-component prediction is used.

[0033] From a second aspect, the present application provides an encoding apparatus for compressing multi-component data, characterized by at least one of the following modules or a combination thereof:

[0034] 1) a prediction encoding module for inter-frame prediction encoding and / or inter-string prediction encoding and / or intra-frame prediction encoding including original data inter-component prediction, the original data inter-component prediction at least including constructing prediction values and prediction residuals of Q (Q≥1) components from original data or reconstructed values of at least H (H≥1) components, wherein H is allowed to be equal to Q, wherein it is allowed that some or all of the H components overlap with some or all of the Q components, and wherein it is allowed that the prediction residual of one or more of the Q components is zero;

[0035] 2) a residual encoding module for residual encoding including residual data inter-component prediction of residual data resulting from the prediction encoding, the residual data inter-component prediction at least including constructing prediction values and prediction residuals of Z (Z≥1) components from residual data or reconstructed values of at least W (W≥1) components, wherein W is allowed to be equal to Z, wherein it is allowed that some or all of the W components overlap with some or all of the Z components, and wherein it is allowed that the prediction residual of one or more of the Z components is zero;

[0036] 3) a compressed data bitstream generation module for writing information indicating whether or not original data inter-component prediction is used and / or whether or not residual data inter-component prediction is used for an encoding block into a compressed data bitstream.

[0037] According to another aspect of the present application, a decoding method or apparatus for compressing multi-component data is provided, at least including steps or modules for performing one or a combination of the following functions and operations:

[0038] parsing a compressed data bitstream to obtain information indicating whether or not original data inter-component prediction is used and / or whether or not residual data inter-component prediction is used for a decoding block;

[0039] performing original data inter-component prediction, the original data inter-component prediction at least including constructing prediction values of Q (Q≥1) components from original data or reconstructed values of at least H (H≥1) components and / or constructing reconstructed values of the Q components from the prediction values of at least the Q components and / or prediction residuals of the Q components or reconstructed values thereof, wherein H is allowed to be equal to Q, wherein it is allowed that some or all of the H components overlap with some or all of the Q components, and wherein it is allowed that the prediction residual of one or more of the Q components or reconstructed values thereof is zero;

[0040] performing residual data inter-component prediction, the residual data inter-component prediction comprising at least constructing a prediction of residual data or its reconstructed values of Z (Z≥1) components from residual data or its reconstructed values of at least W (W≥1) components and / or constructing residual data reconstructed values of the Z components from the prediction of the Z components and / or prediction difference values or their reconstructed values of the Z components, wherein the W is allowed to be equal to the Z, the W components are allowed to overlap with part or all of the Z components, and the prediction difference values or their reconstructed values of one or more of the Z components are allowed to be zero.

[0041] From a third aspect, the present application provides a method of decoding compressed multi-component data, comprising at least one of the following steps or a combination thereof:

[0042] Step 1) parsing the compressed data bitstream to obtain information indicating whether original data inter-component prediction is used and / or whether residual data inter-component prediction is used;

[0043] Step 2) performing original data inter-component prediction, the original data inter-component prediction comprising at least constructing a prediction of original data or its reconstructed values of Q (Q≥1) components from original data or its reconstructed values of at least H (H≥1) components and / or constructing original data reconstructed values of the Q components from the prediction of the Q components and / or prediction difference values or their reconstructed values of the Q components, wherein the H is allowed to be equal to the Q, the H components are allowed to overlap with part or all of the Q components, and the prediction difference values or their reconstructed values of one or more of the Q components are allowed to be zero;

[0044] Step 3) performing residual data inter-component prediction, the residual data inter-component prediction comprising at least constructing a prediction of residual data or its reconstructed values of Z (Z≥1) components from residual data or its reconstructed values of at least W (W≥1) components and / or constructing residual data reconstructed values of the Z components from the prediction of the Z components and / or prediction difference values or their reconstructed values of the Z components, wherein the W is allowed to be equal to the Z, the W components are allowed to overlap with part or all of the Z components, and the prediction difference values or their reconstructed values of one or more of the Z components are allowed to be zero.

[0045] From a fourth aspect, the present application provides a decoding apparatus for compressing multi-component data, comprising at least one of the following modules or a combination thereof:

[0046] 1) compressed data bitstream parsing module: parsing compressed data bitstream, at least obtaining information indicating whether the decoded block uses inter-component prediction of original data and / or whether the decoded block uses inter-component prediction of residual data;

[0047] 2) prediction decoding module: performing inter-component prediction of original data, the operation of the inter-component prediction of original data at least including constructing prediction values of Q (Q≥1) components of original data or reconstructed values thereof from H (H≥1) components of original data or reconstructed values thereof and / or constructing reconstructed values of the Q components of original data from the prediction values of the Q components and / or prediction difference values of the Q components or reconstructed values thereof, wherein the H is allowed to be equal to the Q, a part or all of the H components are allowed to overlap with a part or all of the Q components, and the prediction difference values or reconstructed values thereof of one or more of the Q components are allowed to be zero;

[0048] 3) residual decoding module: if the information indicates that the decoded block uses inter-component prediction of residual data, performing inter-component prediction of residual data for the decoded block, the operation of the inter-component prediction of residual data at least including constructing prediction values of Z (Z≥1) components of residual data or reconstructed values thereof from W (W≥1) components of residual data or reconstructed values thereof and / or constructing reconstructed values of the Z components of residual data from the prediction values of the Z components and / or prediction difference values of the Z components or reconstructed values thereof, wherein the W is allowed to be equal to the Z, a part or all of the W components are allowed to overlap with a part or all of the Z components, and the prediction difference values or reconstructed values thereof of one or more of the Z components are allowed to be zero.

[0049] The present application is applicable to encoding and decoding of data with lossy compression, and is also applicable to encoding and decoding of data with lossless compression. The present application is applicable to encoding and decoding of image data, and is also applicable to encoding and decoding of any one-dimensional, two-dimensional or multi-dimensional data.

[0050] In the present application, data includes one or a combination of the following types of data

[0051] 1) one-dimensional data;

[0052] 2) two-dimensional data;

[0053] 3) multi-dimensional data;

[0054] 4) graph;

[0055] 5) fractal graph;

[0056] 6) image;

[0057] 7) sequence of images;

[0058] 8) a video;

[0059] 9) a three-dimensional scene;

[0060] 10) a sequence of continuously changing three-dimensional scenes;

[0061] 11) a virtual reality scene;

[0062] 12) a sequence of continuously changing virtual reality scenes

[0063] 13) an image in pixel form;

[0064] 14) transform domain data of an image;

[0065] 15) a set of two-dimensional or more than two-dimensional bytes;

[0066] 16) a set of two-dimensional or more than two-dimensional bits;

[0067] 17) a set of pixels;

[0068] 18) a set of pixel components.

[0069] In the present application, in the case where the data is generated from an image, a sequence of images, a video, etc., the coding block or the decoding block is an encoding region or a decoding region of an image, including at least one of the following: the entire image, a sub-image of the image, a slice, a tile, a macroblock, a largest coding unit (LCU), a coding tree unit (CTU), a coding unit (CU), a sub-region of the CU, a sub-coding unit (SubCU), a prediction unit (PU), a sub-region of the PU, a sub-prediction unit (SubPU), a transform unit (TU), a sub-region of the TU, and a sub-transform unit (SubTU).

[0070] In the encoding method or device or the decoding method or device of the present application, the information indicating whether the coding block uses inter-component prediction of original data components and / or whether the coding block uses inter-component prediction of residual data components exists in one or several places in the compressed data code stream:

[0071] 1) a sequence parameter set; usually one or several directly existing or implicitly derived or mixed syntax elements of the sequence parameter set;

[0072] 2) a picture parameter set; usually one or several directly existing or implicitly derived or mixed syntax elements of the picture parameter set;

[0073] 3) a sequence header; usually one or several directly existing or implicitly derived or mixed syntax elements of the sequence header;

[0074] 4) a picture header; usually one or several directly existing or implicitly derived or mixed syntax elements of the picture header;

[0075] 5) slice header; usually one or several directly present or implicitly derived or mixed syntax elements of the slice header;

[0076] 6) CTU header; usually one or several directly present or implicitly derived or mixed syntax elements of the CTU header;

[0077] 7) CU header; usually one or several directly present or implicitly derived or mixed syntax elements of the CU header;

[0078] 8) coding block header; usually one or several directly present or implicitly derived or mixed syntax elements of the coding block header;

[0079] The directly present syntax elements consist of one or more bit strings in the compressed data bitstream. The implicitly derived syntax elements are syntax elements derived from other coding parameters and / or coding variables and / or other syntax elements of the compressed data bitstream or predetermined default values of the syntax elements. The mixed syntax elements are syntax elements mixed from part directly present (i.e. consisting of one or more bit strings in the compressed data bitstream) and part implicitly derived (i.e. derived from other coding parameters and / or coding variables and / or other syntax elements of the compressed data bitstream and / or predetermined default values of the syntax elements).

[0080] The foregoing disclosure of the application will thus provide those skilled in the art with a convenient road map to make and use the application. Other advantages of the application will be apparent from the foregoing disclosure of the application. It will be understood that the application can be practiced with modification and alteration, and that the application should be limited only by the scope of the appended claims. In addition, though the description has been shown and described with reference to particular embodiments thereof, it will be apparent to those skilled in the art that certain changes and modifications can be made therein without departing from the spirit and scope of the application. It is intended to cover in the appended claims all such changes and modifications that fall within the scope of the application. BRIEF DESCRIPTION OF DRAWINGS

[0081] Figure 1 is a schematic diagram of the encoding method or apparatus and the decoding method or apparatus of the present application.

[0082] Figure 2 is the position relationship of the sub-component sample points relative to the primary component sample points in four down-sampling types respectively called type 0, type 1, type 2, type 3. DETAILED DESCRIPTION

[0083] The following are more implementation details or variants of the present application.

[0084] In the encoding method or apparatus or the decoding method or apparatus of the present application, the data is an image or video having one primary component and two sub-components, i.e. three components in total.

[0085] In the encoding method or apparatus or the decoding method or apparatus, the data is an image or video having three components, one primary component and two secondary components, and the three components are one of the following:

[0086] Y luminance component, U chrominance component, V chrominance component, or Y luminance component, Cb chrominance component, Cr chrominance component, or R red component, G green component, B blue component, or G green component, R red component, B blue component, or G green component, B blue component, R red component.

[0087] Embodiment 3

[0088] In the encoding method or apparatus or the decoding method or apparatus, the data is an image or video having three components, one primary component and two secondary components, and the three components are one of the following:

[0089] H = 1 and Q = 2 and / or W = 1 and Z = 2, the two secondary components are predicted using the primary component; in the encoding method or apparatus, the prediction value and the prediction difference value of the original / residual data or the reconstructed value of the two secondary components are constructed from at least the original / residual data or the reconstructed value of the primary component; in the decoding method and apparatus, the reconstructed value of the original / residual data of the two secondary components is constructed from at least the prediction difference value or the reconstructed value thereof

[0090] and / or

[0091] H = 1 and Q = 1 and / or W = 1 and Z = 1, one of the two secondary components is predicted using the other of the two secondary components; in the encoding method or apparatus, the prediction value and the prediction difference value of the original / residual data or the reconstructed value of the other of the two secondary components are constructed from at least the original / residual data or the reconstructed value of one of the two secondary components; in the decoding method and apparatus, the reconstructed value of the original / residual data of one of the two secondary components is constructed from at least the prediction difference value or the reconstructed value thereof

[0092] and / or

[0093] H = 2 and Q = 2 and / or W = 2 and Z = 2, one of the two secondary components is predicted using the other of the two secondary components; in the encoding method or apparatus, the prediction value and the prediction difference value of the original / residual data or the reconstructed value of the other of the two secondary components are constructed from at least the original / residual data or the reconstructed value of one of the two secondary components; in the decoding method and apparatus, the reconstructed value of the original / residual data of one of the two secondary components is constructed from at least the prediction difference value or the reconstructed value thereof.

[0094] Embodiment 4

[0095] In the encoding method or apparatus or the decoding method or apparatus, the data is an image or video having one primary component and two secondary components in total three components, the sampling rate and size of the two secondary components are respectively one half of the sampling rate and size of the primary component, in the inter-component prediction of the original data and the inter-component prediction of the residual data, the primary component is used to predict the two secondary components, the operation of the inter-component prediction of the original data and the operation of the inter-component prediction of the residual data both include the operation of horizontally 2:1 down-sampling or vertically 2:1 down-sampling the primary component.

[0096] Embodiment 5

[0097] In the encoding method or apparatus or the decoding method or apparatus, the data is an image or video having one primary component and two secondary components in total three components, the sampling rate and size of the two secondary components are respectively one fourth of the sampling rate and size of the primary component, in the inter-component prediction of the original data and the inter-component prediction of the residual data, the primary component is used to predict the two secondary components, the operation of the inter-component prediction of the original data and the operation of the inter-component prediction of the residual data both include the operation of horizontally 2:1 down-sampling and vertically 2:1 down-sampling in total 4:1 down-sampling the primary component.

[0098] Embodiment 6

[0099] In the encoding method or apparatus or the decoding method or apparatus of Embodiment 5, the 4:1 down-sampling is to calculate the weighted average value of the values of IxJ primary components as the value of the down-sampled primary component according to one of the following down-sampling formulas:

[0100] Down-sampling Formula 1: to calculate the value of the down-sampled primary component from the values of 2x2 primary components P(2i,2j), P(2i+1,2j), P(2i,2j+1), P(2i+1,2j+1)

[0101] P 420 (i, j) = ((P(2i,2j)+P(2i+1,2j)+P(2i,2j+1)+P(2i+1,2j+1)+2)>>2, wherein >> is 2-bit right shift;

[0102] Down-sampling Formula 2: to calculate the value of the down-sampled primary component from the values of 3x2 primary components P(2i-1,2j), P(2i,2j), P(2i+1,2j), P(2i-1,2j+1), P(2i,2j+1), P(2i+1,2j+1)

[0103] P420 (i, j) = (P(2i-1,2j)+2P(2i,2j)+P(2i+1,2j)+P(2i-1,2j+1)+2P(2i,2j+1)+P(2i+1,2j+1)+4)>>3;

[0104] Down-sampling formula 3: Calculate the value of a down-sampled primary component from the values of 4x2 primary components P(2i-1,2j), P(2i,2j), P(2i+1,2j), P(2i+2,2j), P(2i-1,2j+1), P(2i,2j+1), P(2i+1,2j+1), P(2i+2,2j+1)

[0105] P 420 (i, j) = (P(2i-1,2j)+3P(2i,2j)+3P(2i+1,2j)+P(2i+2,2j)+P(2i-1,2j+1)+3P(2i,2j+1)+3P(2i+1,2j+1)+ P(2i+2,2j+1)+8)>>4;

[0106] Down-sampling formula 4: Calculate the value of a down-sampled primary component from the values of 3x3 primary components P(2i-1,2j-1), P(2i,2j-1), P(2i+1,2j-1), P(2i-1,2j), P(2i,2j), P(2i+1,2j), P(2i-1,2j+1), P(2i,2j+1), P(2i+1,2j+1)

[0107] P 420 (i, j) = (P(2i-1,2j-1)+2P(2i,2j-1)+P(2i+1,2j-1)+2P(2i-1,2j)+4P(2i,2j)+2P(2i+1,2j)+P(2i-1,2j+1)+ 2P(2i,2j+1)+P(2i+1,2j+1)+8)>>4;

[0108] Down-sampling formula 5: Calculate the value of a down-sampled primary component from the values of 2x3 primary components P(2i,2j-1), P(2i+1,2j-1), P(2i,2j), P(2i+1,2j), P(2i,2j+1), P(2i+1,2j+1)

[0109] P 420 (i, j) = ((P(2i,2j-1)+P(2i+1,2j-1)+2P(2i,2j)+2P(2i+1,2j)+P(2i,2j+1)+P(2i+1,2j+1)+4)>>3.

[0110] What down-sampling formula is used is usually determined by the position relationship of the sub-component sampling points relative to the main-component sampling points in a specific down-sampling type type. Figure 2 is the position relationship of the sub-component sampling points relative to the main-component sampling points in the four down-sampling types respectively called type 0, type 1, type 2, type 3.

[0111] Embodiment 7

[0112] In the encoding method or apparatus or the decoding method or apparatus described in Embodiment 5, there is information in the compressed data bitstream that specifies to select one of a predetermined number of down-sampling formulas to perform down-sampling operation on the main-component.

[0113] Embodiment 8

[0114] In the encoding method or apparatus or the decoding method or apparatus described in Embodiment 7, the information that specifies to select one of a predetermined number of down-sampling formulas to perform down-sampling operation on the main-component exists in one or several places in the compressed data bitstream:

[0115] 1) Sequence parameter set; usually one or several syntax elements of the sequence parameter set that exist directly or are derived implicitly or mixed;

[0116] 2) Picture parameter set; usually one or several syntax elements of the picture parameter set that exist directly or are derived implicitly or mixed;

[0117] 3) Sequence header; usually one or several syntax elements of the sequence header that exist directly or are derived implicitly or mixed;

[0118] 4) Picture header; usually one or several syntax elements of the picture header that exist directly or are derived implicitly or mixed;

[0119] The syntax elements that exist directly are composed of one or more bit strings in the compressed data bitstream. The syntax elements that are derived implicitly are syntax elements derived from other encoding parameters and / or codec variables and / or other syntax elements of the compressed data bitstream or predetermined default values of the syntax elements. The mixed syntax elements are mixed syntax elements that exist partially directly (i.e. composed of one or more bit strings in the compressed data bitstream) and partially implicitly (i.e. derived from other encoding parameters and / or codec variables and / or other syntax elements of the compressed data bitstream and / or predetermined default values of the syntax elements).

[0120] Embodiment 9

[0121] In the encoding method or apparatus or the decoding method or apparatus described in Embodiment 8, the one or several syntax elements that exist directly or are derived implicitly or mixed and their semantics are

[0122] downsampling type

[0123] The downsampling type is specified together with the corresponding downsampling formula. If the downsampling type is not present in the compressed data stream, the value of the downsampling type is implicitly derived to be 0.

[0124] Embodiment 10

[0125] In the encoding method or apparatus or the decoding method or apparatus, the data is an image or a video, and the information indicating whether the coding block uses inter-component prediction of original data components and / or whether the coding block uses inter-component prediction of residual data components and the corresponding operation include the following directly or indirectly or directly indirectly mixed flag bits and / or identification codes and associated syntax elements and corresponding operations in italic:

[0126] Secondary component prediction mode flag and / or identification code

[0127] If the value of the secondary component prediction mode flag and / or identification code indicates that the current coding block uses inter-component prediction of original data components, then

[0128] {

[0129] The prediction value of the residual data reconstruction value of the secondary component is constructed from the original data reconstruction value of the primary component of the current coding block

[0130] }

[0131] Prediction mode flag and / or identification code

[0132] If the value of the prediction mode flag and / or identification code indicates that the current coding block uses a number of predetermined prediction modes, then

[0133] {

[0134] The prediction value of the residual data reconstruction value of the secondary component is constructed from the residual data reconstruction value of the primary component of the current coding block

[0135] }

[0136] The direct flag and / or identification code consists of one or more bit strings in the compressed data stream. The indirect flag and / or identification code is a flag and / or identification code derived from other coding parameters and / or coding variables and / or other syntax elements of the compressed data stream. The directly indirectly mixed flag and / or identification code is a flag and / or identification code which is partly direct (i.e. consists of one or more bit strings in the compressed data stream) and partly indirect (i.e. derived from other coding parameters and / or coding variables and / or other syntax elements of the compressed data stream).

[0137] Embodiment 11

[0138] In the encoding method or apparatus or the decoding method or apparatus of Embodiment 10, the plurality of predetermined prediction modes include at least 1) an inter prediction mode, 2) a secondary component direct intra prediction mode, i.e., the secondary component prediction mode directly takes (i.e., is equivalent to) the intra prediction mode of the primary component.

[0139] Embodiment 12

[0140] In the encoding method or apparatus or the decoding method or apparatus of Embodiment 10, the plurality of predetermined prediction modes include at least 1) an inter prediction mode, 2) a secondary component direct intra prediction mode, i.e., the secondary component prediction mode directly takes (i.e., is equivalent to) the intra prediction mode of the primary component, and 3) a secondary component prediction mode using inter-prediction between original data components.

[0141] Embodiment 13

[0142] In the encoding method or apparatus or the decoding method or apparatus, the data is an image or video having one primary component and two secondary components, i.e., three components in total; from the residual data reconstruction value of the primary component, or in the case of 422 sample format, a version thereof down-sampled by 2:1, or in the case of 420 sample format, a version thereof down-sampled by 4:1, denoted as recR L , the residual data reconstruction value of the two secondary components D and E, denoted as C = (D, E), is predicted to obtain a predicted value predR C = (predR D , predR E ).

[0143] predR C = a C *recR L ,

[0144] wherein a C = (a D , a E ) is a two-component multiplication factor, and the two secondary components D and E have their own multiplication factors a D and a E , respectively.

[0145] Embodiment 14

[0146] In the encoding method or apparatus or the decoding method or apparatus of Embodiment 13, the predicted value predR C of the residual data reconstruction value of the secondary component and the predicted difference value △R C = (△R D , △R E) The residual data reconstruction value recR of the secondary component is constructed as follows: C = (recR D , recR E ) :

[0147] recR C =△R C +predR C .

[0148] Embodiment 15

[0149] In the encoding method or apparatus or the decoding method or apparatus of Embodiment 13, the multiplication factors a D and a E are selected from one of the following sets:

[0150] R = {m / 2 n : -2 n+1 ≤ m ≤ 2 n+1} = {0, ±m / 2 n : 1 ≤ m ≤ 2 n+1} = {±m / 2 n : 0 ≤ m ≤ 2 n+1} or a subset of R, where n is a predetermined positive number and m is an integer or a fractional number between -2 n+1 and 2 n+1

[0151] or

[0152] a subset of R, at least including:

[0153] R n = {0, m / 2 n : m = ±2 k , m = ±(2 n + 2 k ), 0 ≤ k ≤ n} or a subset of R n including the subset {0, m / 2 n : m = ±2 k , 0 ≤ k ≤ n} or a subset thereof

[0154] or

[0155] When n = 6,

[0156] ​R6={0, ±0.015625, ±0.03125, ±0.0625, ±0.125, ±0.25, ±0.5, ±1, ±1.015625, ±1.03125, ±1.0625, ±1.125, ±1.25, ±1.5, ±2}={0, ±1 / 64, ±2 / 64, ±4 / 64, ±8 / 64, ±16 / 64, ±32 / 64, ±1, ±(1+1 / 64), ±(1+2 / 64), ±(1+4 / 64), ±(1+8 / 64), ±(1+16 / 64), ±(1+32 / 64), ±2}or a subset thereof

[0157] or

[0158] a subset of R6{0, ±1 / 64, ±2 / 64, ±4 / 64, ±8 / 64, ±16 / 64, ±32 / 64, ±1}or a subset thereof

[0159] or

[0160] a subset of R6{0, ±2 / 64, ±4 / 64, ±8 / 64, ±16 / 64, ±32 / 64, ±1}={0, ±1 / 32, ±2 / 32, ±4 / 32, ±8 / 32, ±16 / 32, ±1}or a subset thereof

[0161] or

[0162] a subset of R6{0, ±8 / 64, ±16 / 64, ±32 / 64, ±1}={0, ±1 / 8, ±2 / 8, ±4 / 8, ±1}or a subset thereof

[0163] or

[0164] a subset of R6{0, ±4 / 64, ±8 / 64, ±16 / 64, ±32 / 64}={0, ±1 / 16, ±2 / 16, ±4 / 16, ±8 / 16}or a subset thereof

[0165] or

[0166] when n = 1,

[0167] R1 = {0, m / 2: m=±2 k , m=±(2+2 k ), 0 ≤ k ≤ 1} = {0, m / 2: m=±1, ±2, ±3, ±4}or a subset thereof

[0168] or

[0169] a subset of {0, ±1 / 2, ±1, ±2} or a subset thereof

[0170] or

[0171] a subset of {0, ±1 / 2, ±1} or a subset thereof

[0172] or

[0173] a subset of {0, ±1} or a subset thereof {0, 1} or {0, -1}.

[0174] Embodiment 16

[0175] In the encoding method or apparatus or the decoding method or apparatus of Embodiment 13, the multiplication factor a D and a E is in the range of R = {0, ±m / 2 n : 1 ≤ m ≤ 2 n+1} = {±m / 2 n : 0 ≤ m ≤ 2 n+1} or a subset thereof, when a X = ±m / 2 n , where X is D or E, a X is a D or a E , the calculation of predR X and predR X is predetermined as one of the following cases:

[0176] predR X = a X *recR L = ±((m*recR L + 2 n-1 )>>n), where >>n is a right shift binary n-bit operation,

[0177] or

[0178] predR X = a X *recR L = ±((m*recR L )>>n),

[0179] or

[0180] predR X = a X *recR L = (((±m)*recR L )>>n).

[0181] Embodiment 17

[0182] In the encoding method or apparatus or the decoding method or apparatus of Embodiment 13, the multiplication factor a D and a E are a function of the size and / or width and / or height of the coding block in which the multiplication factor is located.

[0183] Embodiment 18

[0184] In the encoding method or apparatus or the decoding method or apparatus of Embodiment 13, the multiplication factor a D and a E is synchronized between the encoder and the decoder, i.e., has the same value, by a direct method or an implicit derivation method or a hybrid method.

[0185] The direct method is to represent the value of the multiplication factor a D and a E by a syntax element composed of one or more bit strings (bit strings) directly present in the compressed data bitstream.

[0186] The implicit derivation method is to obtain the value of the multiplication factor a D and a E by calculation and derivation from other encoding parameters and / or coding variables and / or syntax elements in the compressed data bitstream or predetermined syntax element default values that are not directly related to the value of the multiplication factor a D and a E .

[0187] The hybrid method is a method of mixing the direct method and the implicit derivation method.

[0188] Embodiment 19

[0189] In the encoding method or apparatus or the decoding method or apparatus of Embodiment 18,

[0190] The syntax element in the direct method includes

[0191] a syntax element indicating whether the multiplication factor a D and / or a E is zero

[0192] and / or

[0193] a syntax element indicating the sign of the multiplication factor a D and / or a E , i.e., a sign bit syntax element

[0194] and / or

[0195] a syntax element indicating the value of the multiplication factor aD and / or a E the absolute value of the syntax element.

[0196] Embodiment 20

[0197] in the encoding method or apparatus or the decoding method or apparatus of Embodiment 18,

[0198] the implicit derivation manner uses at least the following coding variables to calculate, derive, obtain the multiplication factor a D and / or a E the value of:

[0199] the residual data reconstructed value of the primary component of the current coding block

[0200] and / or

[0201] the residual data reconstructed value of the primary component of the directly adjacent and / or indirectly adjacent pixels of the current coding block

[0202] and / or

[0203] the residual data reconstructed value of the secondary component of the directly adjacent and / or indirectly adjacent pixels of the current coding block.

[0204] Embodiment 21

[0205] in the encoding method or apparatus or the decoding method or apparatus of Embodiment 18,

[0206] the hybrid manner has at least the following features:

[0207] part of the information representing the value of the multiplication factor a D and a E is directly present in the compressed data code stream, and the other part of the information is obtained through the implicit derivation manner, and the value of the multiplication factor a D and a E is obtained from at least the two parts of information.

[0208] Embodiment 22

[0209] in the encoding method or apparatus or the decoding method or apparatus of Embodiment 18,

[0210] the hybrid manner has at least the following features:

[0211] represents a X , wherein X is D or E, i.e., a X is the initial value ia D or a E , of a X is directly present in the compressed data code stream, and the value of a X is obtained from the initial value ia XThe value of a is not directly related to other coding parameters and / or codec variables and / or syntax elements in the compressed data code stream or predetermined syntax element default values, and the a is obtained by calculation and derivation X The value of .

[0212] Example 23

[0213] In the encoding method or device or the decoding method or device described in Example 18,

[0214] The mixing method has at least the following characteristics:

[0215] Indicates a X , where X is D or E i.e. a X is a D or a E , the initial value ia X The information exists directly in the compressed data stream, starting from the initial value ia X And / or at least the following codec variables are calculated, derived, and obtained: X Value:

[0216] The residual data reconstruction value of the principal component of the current codec block

[0217] and / or

[0218] The residual data reconstruction value of the principal component of the directly adjacent and / or indirectly adjacent pixels of the current codec block

[0219] and / or

[0220] The residual data reconstruction values ​​of the sub-components of the directly adjacent and / or indirectly adjacent pixels of the current codec block.

[0221] Example 24

[0222] In the encoding method or device or the decoding method or device described in Example 18,

[0223] The mixing method has at least the following characteristics:

[0224] Indicates a X , where X is D or E i.e. a X is a D or a E , the initial value ia X The information exists directly in the compressed data stream. X The value is equal to ia X + da X , where da X Calculate, derive, or obtain from at least the following codec variables:

[0225] The residual data reconstruction value of the principal component of the current codec block

[0226] and / or

[0227] residual data reconstruction values of the primary components of the directly neighboring and / or indirectly neighboring pixels of the current coding block

[0228] and / or

[0229] residual data reconstruction values of the secondary components of the directly neighboring and / or indirectly neighboring pixels of the current coding block.

[0230] Embodiment 25

[0231] In the direct approach, in the coding method or apparatus or decoding method or apparatus of embodiment 18, the values of a D and a E are jointly binarized, de-binarized, entropy encoded, entropy decoded. D E

[0232] Embodiment 26

[0233] In the direct approach, in the coding method or apparatus or decoding method or apparatus of embodiment 18, the binarization, de-binarization, entropy encoding, entropy decoding of the values of a D depend on the values of a E or the binarization, de-binarization, entropy encoding, entropy decoding of the values of a E depend on the values of a D .

[0234] Embodiment 27

[0235] In the direct approach, in the coding method or apparatus or decoding method or apparatus of embodiment 18, the case where the value of a D is zero and the value of a E is zero is represented by a binary codeword or flag bit (typically 0 or 1) of code length one bit.

[0236] Embodiment 28 (a version about "original data" corresponding to embodiment 13 about "residual data")

[0237] In the coding method or apparatus or decoding method or apparatus, the data is an image or video having three components, one primary component and two secondary components; from the original data reconstruction values of the primary component, or in the case of 422 sampling format, the version thereof down-sampled by 2:1, or in the case of 420 sampling format, the version thereof down-sampled by 4:1, all denoted recP L , the prediction values predP C of the original data reconstruction values of the two secondary components D and E, denoted C = (D, E), are constructed.​= (predP D ,predP E ) of the operation at least includes the following formula:

[0238] predP C = B C + A C *recP L ,

[0239] where B C = (B D , B E ) is a two-component offset, A C = (A D , A E ) is a two-component multiplication factor, and two sub-components D and E have their own offset B D and B E and / or their own multiplication factor A D and A E , respectively.

[0240] Embodiment 29 (a version about "original data" corresponding to Embodiment 14 about "residual data")

[0241] In the encoding method or apparatus or the decoding method or apparatus of Embodiment 28, the prediction value predP C of the original data reconstruction value of the sub-component and the prediction difference value △P C = (△P D , △P E ) of the original data reconstruction value of the sub-component are used to construct the original data reconstruction value recP C = (recP D , recP E ) of the sub-component represented by the following formula:

[0242] recP C =△P C +predP C .

[0243] Embodiment 30

[0244] In the encoding method or apparatus or the decoding method or apparatus of Embodiment 29, the inter-prediction of the original data components and the inter-prediction of the residual data components are used simultaneously, the prediction difference value △P C of the original data reconstruction value is the residual data reconstruction value recR C , and one of the calculation methods of the original data reconstruction value is as follows:

[0245] recP C =△PC + predP C = recR C + predP C = ΔR C + predR C + predP C ,

[0246] where ΔR C and predR C are the prediction difference of the residual data reconstruction value and the predicted value of the residual data reconstruction value in the inter-prediction of residual data components, respectively.

[0247] Embodiment 31 (a version about "original data" corresponding to Embodiment 15 about "residual data")

[0248] In the encoding method or apparatus or the decoding method or apparatus of Embodiment 28, the multiplication factor A D and A E are selected from one of the following sets:

[0249] R = {m / 2 n : -2 n+1 ≤ m ≤ 2 n+1}={0, ±m / 2 n : 1 ≤ m ≤ 2 n+1} = {±m / 2 n : 0≤ m ≤ 2 n+1} or a subset of R, where n is a predetermined positive number and m is an integer or a partial integer between -2 n+1 and 2 n+1

[0250] or

[0251] a subset of R, at least including:

[0252] R n = {0, m / 2 n : m=±2 k , m=±(2 n +2 k ), 0 ≤ k ≤ n} or a subset of R n including the subset {0, m / 2 n : m=±2 k , 0 ≤ k ≤ n} or a subset thereof

[0253] or

[0254] when n = 6,

[0255] ​R6={0, ±0.015625, ±0.03125, ±0.0625, ±0.125, ±0.25, ±0.5, ±1, ±1.015625, ±1.03125, ±1.0625, ±1.125, ±1.25, ±1.5, ±2}={0, ±1 / 64, ±2 / 64, ±4 / 64, ±8 / 64, ±16 / 64, ±32 / 64, ±1, ±(1+1 / 64), ±(1+2 / 64), ±(1+4 / 64), ±(1+8 / 64), ±(1+16 / 64), ±(1+32 / 64), ±2}or a subset thereof

[0256] or

[0257] a subset of R6{0, ±1 / 64, ±2 / 64, ±4 / 64, ±8 / 64, ±16 / 64, ±32 / 64, ±1}or a subset thereof

[0258] or

[0259] a subset of R6{0, ±2 / 64, ±4 / 64, ±8 / 64, ±16 / 64, ±32 / 64, ±1}={0, ±1 / 32, ±2 / 32, ±4 / 32, ±8 / 32, ±16 / 32, ±1}or a subset thereof

[0260] or

[0261] a subset of R6{0, ±8 / 64, ±16 / 64, ±32 / 64, ±1}={0, ±1 / 8, ±2 / 8, ±4 / 8, ±1}or a subset thereof

[0262] or

[0263] a subset of R6{0, ±4 / 64, ±8 / 64, ±16 / 64, ±32 / 64}={0, ±1 / 16, ±2 / 16, ±4 / 16, ±8 / 16}or a subset thereof

[0264] or

[0265] when n = 1,

[0266] R1 = {0, m / 2: m=±2 k , m=±(2+2 k ), 0 ≤ k ≤ 1} = {0, m / 2: m=±1, ±2, ±3, ±4}or a subset thereof

[0267] or

[0268] a subset of {0, ±1 / 2, ±1, ±2} or a subset thereof

[0269] or

[0270] a subset of {0, ±1 / 2, ±1} or a subset thereof

[0271] or

[0272] a subset of {0, ±1} or a subset thereof {0, 1} or {0, -1}.

[0273] Embodiment 32 (a version about “original data” corresponding to Embodiment 16 about “residual data”)

[0274] In the encoding method or apparatus or the decoding method or apparatus of Embodiment 28, the multiplication factor A D and A E is in the range of R = {0, ±m / 2 n : 1 ≤ m ≤ 2 n+1} = {±m / 2 n : 0 ≤ m ≤ 2 n+1} or a subset thereof, when A X = ±m / 2 n , where X is D or E, A X is A D or A E , the calculation operations of predP X and predP X are predetermined as one of the following cases:

[0275] predP X = B X + A X *recP L = B X ± ((m*recP L + 2 n-1 )>>n), where >>n is a right shift binary n-bit operation,

[0276] or

[0277] predP X = B X + A X *recP L = B X ± ((m*recP L )>>n),

[0278] or

[0279] predPX = B X + A X * recP L = B X + (((±m)*recP L )>>n).

[0280] Embodiment 33 (a version about "original data" corresponding to Embodiment 17 about "residual data")

[0281] In the encoding method or apparatus or the decoding method or apparatus of Embodiment 28, the value of the multiplication factor A D and A E is a function of the size and / or width and / or height of the coding block in which the multiplication factor is located.

[0282] Embodiment 34

[0283] In the encoding method or apparatus or the decoding method or apparatus of Embodiment 28, the values of A D , A E , B D , B E are implemented in a direct manner or an implicit derivation manner or a hybrid manner to synchronize between the encoder and the decoder, i.e., have equal values;

[0284] The direct manner is to represent the values of A D , A E , B D , B E by syntax elements composed of one or more bit strings (bit strings) directly existing in the compressed data code stream;

[0285] The implicit derivation manner is to obtain the values of A D , A E , B D , B E by calculation and derivation from other encoding parameters and / or coding variables and / or syntax elements in the compressed data code stream or predetermined syntax element default values that have no direct relationship with the values of A D , A E , B D , B E ;

[0286] The hybrid manner is a manner of mixing the direct manner and the implicit derivation manner.

[0287] Embodiment 35

[0288] In the encoding method or apparatus or the decoding method or apparatus of embodiment 34, the implicit derivation manner uses at least the following coding variables to calculate, derive, or obtain the offset B D and / or B E and / or the value of the multiplication factor A D and / or A E :

[0289] the original data reconstructed value of the primary component of the current coding block

[0290] and / or

[0291] the original data reconstructed value of the primary component of the directly adjacent and / or indirectly adjacent pixels of the current coding block

[0292] and / or

[0293] the original data reconstructed value of the secondary component of the directly adjacent and / or indirectly adjacent pixels of the current coding block.

[0294] Embodiment 36

[0295] In the encoding method or apparatus or the decoding method or apparatus of embodiment 34, the hybrid manner has at least the following features: a part of the information representing the value of A D and / or A E and / or B D and / or B E is directly present in the compressed data code stream, and another part of the information is obtained through the implicit derivation manner, and the value of A D and / or A E and / or B D and / or B E is obtained from at least the two parts of information.

[0296] Embodiment 37

[0297] In the encoding method or apparatus or the decoding method or apparatus of embodiment 34, the hybrid manner has at least the following features: the information representing the value of A D and / or A E is directly present in the compressed data code stream, and the information representing the value of B D and / or B E is obtained through the implicit derivation manner.

[0298] Embodiment 38

[0299] In the encoding method or apparatus or the decoding method or apparatus of embodiment 34, the hybrid manner has at least the following features: the information representing the value of A D and / or A EPart of the information about the value of A exists directly in the compressed data stream, and the other part is obtained by implicit deduction. D and / or A E The value of B D and / or B E The information about the value of is obtained through implicit deduction.

[0300] Example 39

[0301] In the encoding method or apparatus or decoding method or apparatus of embodiment 34, the hybrid mode has at least the following characteristics: D and / or A E Part of the information about the value of A exists directly in the compressed data stream, and the other part is obtained by implicit deduction. D and / or A E value.

[0302] Example 40

[0303] In the encoding method or apparatus or decoding method or apparatus of embodiment 34, the hybrid mode has at least the following characteristics: X , where X is D or E i.e. A X It's A D or A E , the initial value iA X The information is directly present in the compressed data stream, starting from the initial value iA X and / or at least with the A X The value of A is not directly related to other coding parameters and / or codec variables and / or syntax elements in the compressed data code stream or predetermined syntax element default values, and the A is obtained by calculation and derivation X value.

[0304] Example 41

[0305] In the encoding method or apparatus or decoding method or apparatus of embodiment 34, the hybrid mode has at least the following characteristics: X , where X is D or E i.e. A X It's A D or A E , the initial value iA X The information is directly present in the compressed data stream, starting from the initial value iA X And / or at least the following codec variables are calculated, derived, and obtained: X Value:

[0306] The original data reconstruction value of the principal component of the current codec block

[0307] and / or

[0308] raw data reconstructed value of the primary component of the directly neighboring and / or indirectly neighboring pixels of the current coding block

[0309] and / or

[0310] raw data reconstructed value of the secondary component of the directly neighboring and / or indirectly neighboring pixels of the current coding block.

[0311] Embodiment 42

[0312] In the encoding method or apparatus or the decoding method or apparatus of Embodiment 34, the mixing manner has at least the following features: the value of A X , wherein X is D or E, i.e. A X is A D or A E , the initial value iA X of A X is directly present in the compressed data code stream, and the value of A X is equal to iA X + dA X , wherein dA D is calculated, derived, or obtained from at least the following coding variables:

[0313] raw data reconstructed value of the primary component of the current coding block

[0314] and / or

[0315] raw data reconstructed value of the primary component of the directly neighboring and / or indirectly neighboring pixels of the current coding block

[0316] and / or

[0317] raw data reconstructed value of the secondary component of the directly neighboring and / or indirectly neighboring pixels of the current coding block.

[0318] Embodiment 43

[0319] In the encoding method or apparatus or the decoding method or apparatus of Embodiment 34, in the direct manner, the value of the partial combination or the full combination (A D , A E ) of A D and A E is jointly binarized, de-binarized, entropy encoded, and entropy decoded.

[0320] Embodiment 44

[0321] In the encoding method or apparatus or the decoding method or apparatus of Embodiment 34, in the direct manner, the binarization, de-binarization, entropy encoding, and entropy decoding of the value of A D depend on A Evalue of A E de-quantization, entropy encoding, entropy decoding depend on A D value of A

[0322] Embodiment 45

[0323] In the encoding method or apparatus or the decoding method or apparatus of Embodiment 34, in the direct mode, the case where the value of A D is zero and the value of A E is zero is represented by a binary code word or a flag bit (usually 0 or 1) with a code length of one bit.

[0324] Embodiment 46

[0325] In the encoding method or apparatus or the decoding method or apparatus, the data is an image or a video,

[0326] In the sequence parameter set of the compressed data code stream, the following syntax element is present to indicate whether the inter-prediction between original data components is allowed to be used in the coding blocks in the corresponding sequence:

[0327] sps raw cross component prediction enabled flag sps_residual_cross_component_prediction_enabled_flag

[0328] a binary variable. The value of ‘1’ indicates that the inter-prediction between original data components is allowed to be used in the video sequence; the value of ‘0’ indicates that the inter-prediction between original data components is not used in the video sequence.

[0329] and / or

[0330] In the sequence header of the compressed data code stream, the following syntax element is present to indicate whether the inter-prediction between original data components is allowed to be used in the coding blocks in the corresponding sequence:

[0331] pps raw cross component prediction enabled flag pic_raw_cross_component_prediction_enabled_flag

[0332] a binary variable. The value of ‘1’ indicates that the inter-prediction between original data components is allowed to be used in the video sequence; the value of ‘0’ indicates that the inter-prediction between original data components is not used in the video sequence.

[0333] and / or

[0334] In the picture parameter set of the compressed data code stream, the following syntax element is present to indicate whether the inter-prediction between original data components is allowed to be used in the coding blocks in the corresponding picture:

[0335] slice_raw_cross_component_prediction_enabled_flag sps residual cross component prediction enabled flag

[0336] a binary variable. The value of ‘1’ indicates that the inter-prediction between original data components is allowed to be used in the picture; the value of ‘0’ indicates that the inter-prediction between original data components is not used in the picture.

[0337] and / or

[0338] In the picture header of the compressed data stream, there is the following syntax element to indicate whether the coding blocks in the corresponding picture are allowed to use the original data inter-component prediction:

[0339] seq_residual_cross_component_prediction_enabled_flag pps residual cross component prediction enabled flag

[0340] a binary variable; a value of '1' indicates that the picture is allowed to use the original data inter-component prediction; a value of '0' indicates that the picture does not use the original data inter-component prediction;

[0341] and / or

[0342] In the slice header of the compressed data stream, there is the following syntax element to indicate whether the coding blocks in the corresponding slice are allowed to use the original data inter-component prediction:

[0343] pic_residual_cross_component_prediction_enabled_flag slice_residual_cross_component_prediction_enabled_flag

[0344] a binary variable; a value of '1' indicates that the slice is allowed to use the original data inter-component prediction; a value of '0' indicates that the slice does not use the original data inter-component prediction;

[0345] and / or

[0346] In the sequence parameter set of the compressed data stream, there is the following syntax element to indicate whether the coding blocks in the corresponding sequence are allowed to use the residual data inter-component prediction:

[0347] pps ccp multiplier value range flag pic ccp multiplier value range flag

[0348] a binary variable; a value of '1' indicates that the video sequence is allowed to use the residual data inter-component prediction; a value of '0' indicates that the video sequence does not use the residual data inter-component prediction;

[0349] and / or

[0350] In the sequence header of the compressed data stream, there is the following syntax element to indicate whether the coding blocks in the corresponding sequence are allowed to use the residual data inter-component prediction:

[0351] slice ccp multiplier value range flag cb D mode flag

[0352] a binary variable; a value of '1' indicates that the video sequence is allowed to use the residual data inter-component prediction; a value of '0' indicates that the video sequence does not use the residual data inter-component prediction;

[0353] and / or

[0354] In the picture parameter set of the compressed data stream, there is the following syntax element to indicate whether the inter-component residual prediction is allowed to be used in the coding blocks of the corresponding picture:

[0355] cb E mode flag cb be 0 flag

[0356] a binary variable; value ‘1’ means the inter-component residual prediction is allowed to be used in the picture; value ‘0’ means the inter-component residual prediction is not used in the picture;

[0357] and / or

[0358] In the picture header of the compressed data stream, there is the following syntax element to indicate whether the inter-component residual prediction is allowed to be used in the coding blocks of the corresponding picture:

[0359] pps ccp multiplier value range flag pic ccp multiplier value range flag

[0360] a binary variable; value ‘1’ means the inter-component residual prediction is allowed to be used in the picture; value ‘0’ means the inter-component residual prediction is not used in the picture;

[0361] and / or

[0362] In the slice header of the compressed data stream, there is the following syntax element to indicate whether the inter-component residual prediction is allowed to be used in the coding blocks of the corresponding slice:

[0363] slice ccp multiplier value range flag ​

[0364] a binary variable; value ‘1’ means the inter-component residual prediction is allowed to be used in the slice; value ‘0’ means the inter-component residual prediction is not used in the slice.

[0365] Embodiment 47

[0366] In the encoding method or apparatus or the decoding method or apparatus, when at least the original inter-component prediction and / or the inter-component residual prediction is used for coding and the prediction difference of the generated component is quantized and dequantized, the quantization degree of the component is adjusted; one of the adjustment ways is to increase or decrease the value of the quantization parameter, also known as the quantization factor QP, wherein the increase or decrease is a predetermined constant, usually less than 10.

[0367] Embodiment 48 (a version about “two-component prediction” corresponding to Embodiment 13 or 28 about “three-component prediction”)

[0368] In the encoding method or apparatus or the decoding method or apparatus, the original data and / or residual data, referred to as original / residual data, has at least two components D and E, and E and D are predicted respectively using D and E;

[0369] In the encoding method or apparatus, the operation of constructing the predicted value predC = (predD, predE) and the prediction difference △C = (△D, △E) of the original / residual data from at least the original / residual data E and D of the two components includes at least the following formula:

[0370] predC = (-a*E, a*D)

[0371] and

[0372] (△D, △E) = △C = (C-PredC) / d = ((D, E)-(-a*E, a*D)) / d = ((D + a*E, E-a*D)) / d

[0373] where a is a multiplication factor, and d = 1 or d = 1 + a 2 ; obviously, a*△D = (a*D + a 2 *E) / d, a*△E = (a*E-a 2 *D) / d, thus △D-a*△E = (D + a*E-(a*E-a 2 *D)) / d = (D + a 2 *D) / d and △E + a*△D = (E-a*D + a*D + a 2 *E) / d = (E + a 2 *E) / d, and it can be seen that the relationship between the prediction difference △D and △E and the two components D and E is:

[0374] D = (△D-a*△E)*d / (1 + a 2 ) and E = (△E + a*△D)*d / (1 + a 2 );

[0375] In the decoding method or apparatus, the calculation of the original / residual data reconstruction values recD and recE of the two components from at least the prediction difference reconstruction values rec△D and rec△E of the two components is as follows:

[0376] recD = (rec△D-a*rec△E)*d / (1 + a 2 ) and recE = (rec△E + a*rec△D)*d / (1 + a2 ),

[0377] wherein the predicted difference reconstructed values rec△D and rec△E are the results of encoding operations including prediction and / or transform and / or quantization and inverse operations thereof on the predicted differences △D and △E; obviously, when a=0, the predicted value predC of the original / residual data is zero, the original / residual data is equal to the predicted difference, and the original / residual data reconstructed value is equal to the predicted difference reconstructed value.

[0378] Embodiment 49 (a version about “two-component prediction” corresponding to Embodiment 15 or 31 about “three-component prediction”)

[0379] In the encoding method or apparatus or the decoding method or apparatus of Embodiment 48, the multiplication factor a is in one of the following sets:

[0380] R = {m / 2 n : -2 n+1 ≤ m ≤ 2 n+1}={0, ±m / 2 n : 1 ≤ m ≤ 2 n+1} = {±m / 2 n : 0≤ m ≤ 2 n+1}or a subset of R, wherein n is a predetermined positive number and m is all integers or partial integers between -2 n+1 and 2 n+1

[0381] or

[0382] a subset of R, at least including:

[0383] R n = {0, m / 2 n : m=±2 k , m=±(2 n +2 k ), 0 ≤ k ≤ n}or a subset of R n , including the subset {0, m / 2 n : m=±2 k , 0 ≤ k ≤ n} or a subset thereof

[0384] or

[0385] When n=6,

[0386] ​R6={0, ±0.015625, ±0.03125, ±0.0625, ±0.125, ±0.25, ±0.5, ±1, ±1.015625, ±1.03125, ±1.0625, ±1.125, ±1.25, ±1.5, ±2}={0, ±1 / 64, ±2 / 64, ±4 / 64, ±8 / 64, ±16 / 64, ±32 / 64, ±1, ±(1+1 / 64), ±(1+2 / 64), ±(1+4 / 64), ±(1+8 / 64), ±(1+16 / 64), ±(1+32 / 64), ±2}or a subset thereof

[0387] or

[0388] a subset of R6{0, ±1 / 64, ±2 / 64, ±4 / 64, ±8 / 64, ±16 / 64, ±32 / 64, ±1}or a subset thereof

[0389] or

[0390] a subset of R6{0, ±2 / 64, ±4 / 64, ±8 / 64, ±16 / 64, ±32 / 64, ±1}={0, ±1 / 32, ±2 / 32, ±4 / 32, ±8 / 32, ±16 / 32, ±1}or a subset thereof

[0391] or

[0392] a subset of R6{0, ±8 / 64, ±16 / 64, ±32 / 64, ±1}={0, ±1 / 8, ±2 / 8, ±4 / 8, ±1}or a subset thereof

[0393] or

[0394] a subset of R6{0, ±4 / 64, ±8 / 64, ±16 / 64, ±32 / 64}={0, ±1 / 16, ±2 / 16, ±4 / 16, ±8 / 16}or a subset thereof

[0395] or

[0396] when n = 1,

[0397] R1 = {0, m / 2: m=±2 k , m=±(2+2 k ), 0 ≤ k ≤ 1} = {0, m / 2: m=±1, ±2, ±3, ±4}or a subset thereof

[0398] or

[0399] a subset of {0, ±1 / 2, ±1, ±2} or a subset thereof

[0400] or

[0401] a subset of {0, ±1 / 2, ±1} or a subset thereof

[0402] or

[0403] a subset of {0, ±1} or a subset of {0, 1} or {0, -1}.

[0404] Embodiment 50

[0405] In the encoding method or apparatus or the decoding method or apparatus of Embodiment 48, d = 1 + a 2 ,

[0406] When a is not zero, rec△E or rec△D is set to zero, and in the decoding method or apparatus, the original / residual data reconstruction values recD and recE of the two components are constructed from at least rec△D or rec△E in the following manner:

[0407] recD = rec△D and recE = -a*rec△D

[0408] or

[0409] recD = -a*rec△E and recE = rec△E;

[0410] When a is zero, the original / residual data reconstruction values recD and recE of the two components are constructed in the following manner:

[0411] recD = rec△D and recE = rec△E.

[0412] Embodiment 51

[0413] In the encoding method or apparatus or the decoding method or apparatus of Embodiment 50,

[0414] When a is not zero, at least information necessary to obtain the prediction difference reconstruction value rec△E is present in the compressed data stream, but information necessary to obtain the prediction difference reconstruction value rec△D is not present;

[0415] When a is zero, at least information necessary to obtain the prediction difference reconstruction values rec△D and rec△E of the two components is present in the compressed data stream.

[0416] Embodiment 52

[0417] In the encoding method or apparatus or the decoding method or apparatus of embodiment 51, the information needed for representing and obtaining rec△D and / or rec△E includes at least information representing and obtaining results of encoding operations on the prediction difference △D and / or △E including prediction and / or transform and / or quantization or at least information representing and obtaining results of encoding operations on the prediction difference △D and / or △E including quantization.

[0418] Embodiment 53

[0419] In the encoding method or apparatus or the decoding method or apparatus of embodiment 50, the multiplication factor a takes values in the range of {0, ±1 / 2, ±1, ±2} or a subset thereof.

[0420] Embodiment 54

[0421] In the encoding method or apparatus or the decoding method or apparatus of embodiment 53, when the coding block is in intra coding mode, the multiplication factor a takes values in the range of R 11 ={0, 1 / 2, 1} or R 12 ={0, -1 / 2, -1}, otherwise, the multiplication factor a takes values in the range of R 21 ={0, 1} or R 22 ={0, -1}.

[0422] Embodiment 55

[0423] In the encoding method or apparatus or the decoding method or apparatus of embodiment 54, the following syntax elements are present in the picture parameter set or the picture header or the slice header of the compressed data bitstream to represent the range of the inter-component prediction multiplication factor a for all coding blocks in the corresponding picture or slice:

[0424] ​ ​

[0425] or

[0426] ​ ​

[0427] or

[0428] ​ ​

[0429] a binary variable; value ‘1’ indicates that, in the corresponding picture or slice, when the coding block is in intra coding mode, the multiplication factor a takes values in the range of R 11 , otherwise, the multiplication factor a takes values in the range of R 21; the value of '0' indicates that in the corresponding picture or slice, when the coding block adopts the intra coding mode, the value range of the multiplication factor a is R 12 , otherwise, the value range of the multiplication factor a is R 22 .

[0430] Embodiment 56

[0431] In the encoding method or device or the decoding method or device of Embodiment 50, in the coding block header of the compressed data code stream, there are the following syntax elements with the value of the binary variable:

[0432] ​ , ​ ​ , ​ The value of a and which component is set to zero are determined by the values of the three flag bits,

[0433] When the coding block adopts the intra coding mode, the set-to-zero component and the value of a are determined by the following table:

[0434] When the coding block does not adopt the intra coding mode, the set-to-zero component and the value of a are determined by the following table:

[0435] In the above table, whether the value of a that is not zero is positive or negative is determined by the value of ​ ​ or ​ or ​ ​ , wherein x represents 0 or 1, the value of 0 indicates that all the prediction difference values of the corresponding component D or E in the coding block are zero, and the value of 1 indicates that not all the prediction difference values of the corresponding component D or E in the coding block are zero.

[0436] Embodiment 57

[0437] In the encoding method or device or the decoding method or device of Embodiment 56, multiplication by a = 1 / 2 is right shift by 1 bit, and multiplication by a = -1 / 2 is multiplication by -1 followed by right shift by 1 bit.

Claims

1. A method of decoding video compressed data having three components, one luminance component and two chrominance components, characterized in that The method comprises the following steps: parsing a compressed data stream to obtain information indicating whether residual data inter-component prediction is used for a decoding block; performing original data inter-component prediction, which comprises constructing a prediction value of original data or a reconstructed value of original data of two chroma components from original data or a reconstructed value of original data of one luma component and / or constructing a reconstructed value of original data of the two chroma components from at least the prediction value of the two chroma components and / or a prediction difference value or a reconstructed value of a prediction difference value of the two chroma components; performing residual data inter-component prediction, which comprises: the residual data has two chroma components D and E; the residual data reconstructed values recD and recE of the two chroma components are constructed from at least the prediction difference reconstructed values rec△D and rec△E of the two chroma components according to the following formula: recD = rec△D - a*rec△E = rec△D + a*(-rec△E) = rec△D + (-a)*rec△E and recE = rec△E + a*rec△D, wherein a is a multiplication factor, the prediction difference reconstructed values rec△D and rec△E are results of performing encoding operations including prediction and / or transform and / or quantization on the prediction difference values△D and△E and inverse operations thereof; the multiplication factor a is in the range of {0, ±1 / 2, ±1} or a subset thereof; wherein the multiplication of a = 1 / 2 is right shifting by 1 bit, and the multiplication of a = -1 / 2 is right shifting by 1 bit after multiplication by -1; the luma component, the chroma component D, and the chroma component E are also denoted as Y luma component, U chroma component, and V chroma component or as Y luma component, Cb chroma component, and Cr chroma component.

2. The decoding method of claim 1, wherein The method comprises the following features 1 and / or feature 2: feature 1: the decoding block is a decoding region of an image, which comprises at least one of the following: slice, tile, macroblock, largest coding unit (LCU), coding tree unit (CTU), coding unit (CU), sub-region of CU, sub-coding unit (SubCU), prediction unit (PU), sub-region of PU, sub-prediction unit (SubPU), transform unit (TU), sub-region of TU, sub-transform unit (SubTU), transform block; feature 2: the information indicating whether residual data inter-component prediction is used for a decoding block is present in one or more of the following places in the compressed data stream: 1) sequence parameter set; the presentation form includes one or more syntax elements directly present or implicitly derived or mixed in the sequence parameter set; 2) picture parameter set; the presentation form includes one or more syntax elements directly present or implicitly derived or mixed in the picture parameter set; 3) sequence header; the presentation form includes one or more syntax elements directly present or implicitly derived or mixed in the sequence header; 4) picture header; the presentation form includes one or more syntax elements directly present or implicitly derived or mixed in the picture header; 5) slice header; the manifestations include one or more syntax elements directly present or implicitly derived or mixed in the slice header; 6) CTU header; the manifestations include one or more syntax elements directly present or implicitly derived or mixed in the CTU header; 7) CU header; the manifestations include one or more syntax elements directly present or implicitly derived or mixed in the CU header; 8) decoded block header; the manifestations include one or more syntax elements directly present or implicitly derived or mixed in the decoded block header; The directly present syntax elements are composed of one or more bit strings in the compressed data code stream; the implicitly derived syntax elements are syntax elements derived from other encoding parameters and / or decoding variables and / or other syntax elements of the compressed data code stream or predetermined syntax element default values; the mixed syntax elements are partially directly present, i.e. composed of one or more bit strings in the compressed data code stream, and partially implicitly derived, i.e. derived from other encoding parameters and / or decoding variables and / or other syntax elements of the compressed data code stream and / or predetermined syntax element default values.

3. The decoding method of claim 1, wherein, The data is an image or video with three components of 420 sample format, one luminance component and two chrominance components, the sampling rate and size of the two chrominance components are respectively one fourth of the sampling rate and size of the luminance component, in the original data inter-component prediction, the two chrominance components are predicted using the luminance component, the operation of the original data inter-component prediction includes the operation of horizontal 2:1 down-sampling and vertical 2:1 down-sampling overall 4:1 down-sampling of the luminance component.

4. The decoding method of claim 3, wherein, The 4:1 down-sampling is to calculate the weighted average value of I×J luminance component values as the value of the down-sampled luminance component according to one of the following down-sampling formulas: Down-sampling formula 1: calculate the value of the down-sampled luminance component from the values of 2×2 luminance components P(2i,2j), P(2i+1,2j), P(2i,2j+1), P(2i+1,2j+1) P 420 (i, j) = ((P(2i,2j)+P(2i+1,2j)+P(2i,2j+1)+P(2i+1,2j+1)+2)>>2, where >> is a binary right shift. Down-sampling formula 2: calculate the value of the down-sampled luminance component from the values of 3×2 luminance components P(2i-1,2j), P(2i,2j), P(2i+1,2j), P(2i-1,2j+1), P(2i,2j+1), P(2i+1,2j+1) P 420 (i, j) = (P(2i-1,2j)+2P(2i,2j)+P(2i+1,2j)+P(2i-1,2j+1)+2P(2i,2j+1)+P(2i+1,2j+1)+4)>>3; Down-sampling formula 3: calculate the value of the down-sampled luminance component from the values of 4×2 luminance components P(2i-1,2j), P(2i,2j), P(2i+1,2j), P(2i+2,2j), P(2i-1,2j+1), P(2i,2j+1), P(2i+1,2j+1), P(2i+2,2j+1) P 420 (i, j) = (P(2i-1,2j)+3P(2i,2j)+3P(2i+1,2j)+P(2i+2,2j)+P(2i-1,2j+1)+3P(2i,2j+1)+3P(2i+1,2j+1)+ P(2i+2,2j+1)+8)>>4; Downsampling formula 4: calculate the value of the downsampled luma component from the values of 3x3 luma components P(2i-1,2j-1), P(2i,2j-1), P(2i+1,2j-1), P(2i-1,2j), P(2i,2j), P(2i+1,2j), P(2i-1,2j+1), P(2i,2j+1), P(2i+1,2j+1) P 420 (i, j) = (P(2i-1,2j-1)+2P(2i,2j-1)+P(2i+1,2j-1)+2P(2i-1,2j)+4P(2i,2j)+2P(2i+1,2j)+P(2i-1,2j+1)+ 2P(2i,2j+1)+P(2i+1,2j+1)+8)>>4; Downsampling formula 5: calculate the value of the downsampled luma component from the values of 2x3 luma components P(2i,2j-1), P(2i+1,2j-1), P(2i,2j), P(2i+1,2j), P(2i,2j+1), P(2i+1,2j+1) P 420 (i, j) = ((P(2i,2j-1)+P(2i+1,2j-1)+2P(2i,2j)+2P(2i+1,2j)+P(2i,2j+1)+P(2i+1,2j+1)+4)>>3.

5. The decoding method of claim 3, wherein, there is information in the compressed data bitstream that specifies to select one of the predetermined number of downsampling formulas to downsample the luma components.

6. The decoding method of claim 5, wherein, the information that specifies to select one of the predetermined number of downsampling formulas to downsample the luma components is in one or more of the following places in the compressed data bitstream: 1) sequence parameter set; the presentation form includes one or more predetermined syntax elements directly present or implicitly derived or mixed in the sequence parameter set; 2) picture parameter set; the presentation form includes one or more predetermined syntax elements directly present or implicitly derived or mixed in the picture parameter set; 3) sequence header; the presentation form includes one or more predetermined syntax elements directly present or implicitly derived or mixed in the sequence header; 4) picture header; the presentation form includes one or more predetermined syntax elements directly present or implicitly derived or mixed in the picture header; the directly present syntax element is composed of one or more bit strings in the compressed data bitstream; the implicitly derived syntax element is a syntax element derived from other coding parameters and / or decoding variables and / or other syntax elements of the compressed data bitstream or a predetermined syntax element default value; the mixed syntax element is partially directly present, i.e. composed of one or more bit strings in the compressed data bitstream, and partially implicitly derived, i.e. derived from other coding parameters and / or decoding variables and / or other syntax elements of the compressed data bitstream and / or a predetermined syntax element default value.

7. The decoding method of claim 6, wherein, the predetermined one or more syntax elements directly present or implicitly derived or mixed and their semantics are downsampling type downsampling_type specifying the downsampling type and the corresponding downsampling formula; if the downsampling_type is not present in the compressed data bitstream, the value of downsampling_type is implicitly derived to be 0.

8. The decoding method of claim 1, wherein, in the sequence parameter set of the compressed data bitstream, the following syntax element is present to indicate whether the inter-prediction between residual data components is allowed to be used in the corresponding sequence: sps_residual_cross_component_prediction enabled_flag binary variable; value of '1' indicates that residual cross-component prediction is enabled for the video sequence; value of '0' indicates that residual cross-component prediction is not used for the video sequence; and / or In the sequence header of the compressed data bitstream, the following syntax element is present to indicate whether residual cross-component prediction is allowed for the decoded blocks in the corresponding sequence: seq_residual_cross_component_prediction enabled_flag binary variable; value of '1' indicates that residual cross-component prediction is enabled for the video sequence; value of '0' indicates that residual cross-component prediction is not used for the video sequence; and / or In the picture parameter set of the compressed data bitstream, the following syntax element is present to indicate whether residual cross-component prediction is allowed for the decoded blocks in the corresponding picture: pps_residual_cross_component_prediction enabled_flag binary variable; value of '1' indicates that residual cross-component prediction is enabled for the picture; value of '0' indicates that residual cross-component prediction is not used for the picture; and / or In the picture header of the compressed data bitstream, the following syntax element is present to indicate whether residual cross-component prediction is allowed for the decoded blocks in the corresponding picture: pic_residual_cross_component_prediction enabled_flag binary variable; value of '1' indicates that residual cross-component prediction is enabled for the picture; value of '0' indicates that residual cross-component prediction is not used for the picture; and / or In the slice header of the compressed data bitstream, the following syntax element is present to indicate whether residual cross-component prediction is allowed for the decoded blocks in the corresponding slice: slice_residual_cross_component_prediction enabled_flag binary variable; value of '1' indicates that residual cross-component prediction is enabled for the slice; value of '0' indicates that residual cross-component prediction is not used for the slice.

9. The decoding method according to claim 1, wherein, when at least one of the residual cross-component prediction is used for decoding and the prediction difference of one of the components is quantized and dequantized, the quantization degree of the component is adjusted; one of the adjustment is to increase or decrease the value of the quantization parameter, also called quantization factor, QP, by a predetermined constant.

10. An apparatus for decoding video compressed data having three components, one luminance component and two chrominance components, characterized by, A module for implementing a method for decoding video compressed data having three components, one luminance component and two chrominance components, according to any one of claims 1 to 9.

Images