Abstract: An intra prediction method and device and a computer-readable storage medium, the method comprising: configuring actual angle modes indicated by relative angle numbers, wherein the relative angle numbers are successively represented within a prediction direction range corresponding to a preset width and height relationship; starting from a starting angle, using a corresponding actual angle mode after sampling preset angle sample points, said starting angle being determined according to the width and height relationship of processing blocks and the prediction direction range corresponding to the preset width and height relationship, and actual angles having a one-to-one correspondence with the actual angle modes.

Abstract: A method for intra prediction includes: obtaining multiple previously reconstructed neighbouring blocks corresponding to a current processing block; determining prediction modes, that are signalled in a bitstream, corresponding to neighbouring blocks of the multiple previously reconstructed neighbouring blocks, to obtain multiple first prediction modes; if the multiple first prediction modes comprise at least two directional modes, taking directional modes comprised in the multiple first prediction modes as first prediction directions; performing, according to a preset operation rule, operation on multiple first prediction directions of the first prediction directions to obtain second prediction directions; obtaining a prediction mode set according to the second prediction directions and the multiple first prediction modes; and performing intra prediction on the current processing block based on the prediction mode set.

Abstract: A method for colour component prediction, an encoder, a decoder and a storage medium are provided. The method includes that: prediction parameters of a current block are determined, the prediction parameters including a prediction mode parameter and a size parameter of the current block; when the prediction mode parameter indicates that a Matrix-based Intra Prediction (MIP) mode is adopted to determine an intra prediction value of the current block, an MIP weight matrix of the current block, a shift factor of the current block and an MIP input sample matrix of the current block are determined; and the intra prediction value of the current block is determined according to the MIP weight matrix, the shift factor and the MIP input sample matrix.

Abstract: Methods for determining a prediction value, an encoder, and a decoder are provided. Reconstructed values of neighboring samples of a current block are acquired, and then filtered to obtain a reference value set of the current block. When a size of the current block is smaller than a preset threshold value, a first constant value is calculated according to a bit depth value of a luma component of a sample in the current block. A difference between the first constant value and a first reference value in the reference value set is determined as a first prediction input value in a prediction input value set. Other prediction input values in the prediction input value set other than the first prediction input value are determined according to the reference value set. Prediction values of samples at specific positions in the current block is calculated and then filtered.

Abstract: Chroma intra prediction methods and devices are provided. The method comprises parsing bitstream data corresponding to a current chroma block, and determining that a prediction mode corresponding to the current chroma block is DM; before determining a set of chroma prediction modes based on at least one modified candidate mode, acquiring a linear mode corresponding to the current chroma block; determining an intra prediction mode of the current chroma block from the set of chroma prediction modes, wherein the set of chroma prediction modes comprises at least one of the DM, LM, LM_T or LM_L, wherein when a luma prediction mode corresponding to the DM is one of a DC mode, Planar mode, VER mode or HOR mode, the set of modes comprises an angular mode with an index number 66; and determining a reconstructed value of the current chroma block according to the intra prediction mode.

Abstract: Provided are a picture encoding and decoding method, an encoder, a decoder and a storage medium. The decoder decodes a bitstream to obtain a size, a coding mode, and residuals of a current block; when the coding mode of the current block is an MIP mode, calculates a second offset based on the size of the current block, a first offset and reconstructed values of adjacent pixels corresponding to the current block; determines a first prediction value of the current block according to the second offset; and determines a reconstructed value of the current block based on the first prediction value.

Abstract: An image decoding method, a decoder and a storage medium are provided. The method includes: receiving code stream data, and parsing the code stream data to obtain a coding tree unit corresponding to the code stream data; parsing an i-th node of i-th layer corresponding to the coding tree unit to obtain i-th state parameter and i-th flag parameter corresponding to the i-th node; performing detection processing on the i-th node according to the i-th state parameter and the i-th flag parameter to obtain an i-th detection result; acquiring a (i+1)th node of a (i+1)th layer corresponding to the coding tree unit; continuing to perform detection processing on the (i+1)th node, and traversing all the nodes corresponding to the coding tree unit until all the coding unit data corresponding to the coding tree unit is obtained; and generating a decoded image corresponding to the code stream data.

Abstract: Chroma intra prediction methods and devices are provided. The method comprising: parsing bitstream data corresponding to a current chroma block, and determining that a prediction mode corresponding to the current chroma block is DM; before determining a set of chroma prediction modes based on at least one modified candidate mode, acquiring a linear mode corresponding to the current chroma block from the bitstream data; determining an intra prediction mode of the current chroma block from the set of chroma prediction modes, wherein the set of chroma prediction modes comprises at least one of the DM, LM, LM_T or LM_L, wherein when a luma prediction mode corresponding to the DM is a DC mode or a planar mode, the set of chroma prediction modes comprises a diagonal angular mode with prediction direction index number 66, determining a reconstructed value of the current chroma block according to the intra prediction mode.

Abstract: A prediction method, an encoder, a decoder, and a computer storage medium are provided. The prediction method applied to an encoder includes: determining a spatial block in which an encoding point is located; constructing a prediction model according to the spatial block; acquiring a value of a first colour component and a value of a second colour component of the encoding point; obtaining a prediction value of the second colour component of the encoding point by using the prediction model and the value of the first colour component; calculating a difference between the value of the second colour component and the prediction value of the second colour component, and using the obtained difference as a residual of the encoding point; and performing Level of Detail (LOD) partitioning and lifting transform based on the residual of the encoding point.

Abstract: A method for colour component prediction, an encoder, a decoder and a storage medium are provided. The method includes that: prediction parameters of a current block are determined, the prediction parameters including a prediction mode parameter and a size parameter of the current block; when the prediction mode parameter indicates that a Matrix-based Intra Prediction (MIP) mode is adopted to determine an intra prediction value of the current block, an MIP weight matrix of the current block, a shift factor of the current block and an MIP input sample matrix of the current block are determined; and the intra prediction value of the current block is determined according to the MIP weight matrix, the shift factor and the MIP input sample matrix.

Abstract: An image decoding method, a decoder and a storage medium are provided. The method includes: receiving code stream data, and parsing the code stream data to obtain a coding tree unit corresponding to the code stream data; parsing an i-th node of i-th layer corresponding to the coding tree unit to obtain i-th state parameter and i-th flag parameter corresponding to the i-th node; performing detection processing on the i-th node according to the i-th state parameter and the i-th flag parameter to obtain an i-th detection result; acquiring a (i+1)th node of a (i+1)th layer corresponding to the coding tree unit; continuing to perform detection processing on the (i+1)th node, and traversing all the nodes corresponding to the coding tree unit until all the coding unit data corresponding to the coding tree unit is obtained; and generating a decoded image corresponding to the code stream data.

Abstract: A method and apparatus for inter prediction. According to the position of a current block in a video picture, first motion information and second candidate motion information is determined, the motion information at least includes a motion vector; it is determined whether the distance between the motion vector of the first motion information and the motion vector of the second candidate motion information is greater than a first threshold; if the determination result is that the distance is less than or equal to the first threshold, the second candidate motion information is updated to obtain second motion information; if the determination result is that the distance is greater than the first threshold, the second candidate motion information is taken as the second motion information; and inter prediction is performed on the current block by using the first motion information and the second motion information.

Abstract: Chroma intra prediction methods and devices are provided. The method comprises: decoding bitstream data corresponding to a current block, and determining that a prediction mode corresponding to a chroma component of the current block is a direct mode (DM); determining an intra prediction mode of a chroma component of the current block from a set of chroma prediction modes, wherein the set of chroma prediction modes comprises at least one of the DM derived modes, LM, LM_T or LM_L; and determining a reconstructed value of the current chroma block according to the intra prediction mode.

Abstract: The implementation of the present disclosure provides a point cloud partitioning method and device, and a computer-readable storage medium, including: when performing stripe division along the longest side, adjusting an initial partitioning position or determining the stripe division length according to the size of a preset block, to obtain a stripe division position, wherein, the length of the first n?1 stripes along the longest side is an integer multiple of the side length of the preset block, n is the number of divided stripes, and n is a positive integer greater than or equal to 2.

Abstract: A method and device for intra prediction are provided. The method includes: when determining that a current level obtained by partitioning an input point cloud is lower than a target level, obtaining occupation information of a first number of neighbouring nodes of a current node; extracting occupation information of a second number of neighbouring nodes from the occupation information of the first number of neighbouring nodes, the first number being greater than the second number, and the second number of neighbouring nodes being in an association relationship with a child node of the current node, and performing intra prediction on occupation information of the child node of the current node based on the occupation information of the second number of neighbouring nodes to obtain a first prediction result.

Abstract: Provided are an intra prediction method and apparatus, and a computer-readable storage medium. The method includes: acquiring a first reference sample set corresponding to the current processing block, wherein the first reference sample set includes at least one of a reference row adjacent to the current processing block and a reference column adjacent to the current processing block; selecting, based on a pre-set selection method, a second reference sample set from the first reference sample set, wherein the second reference sample set includes at least one reference sample in the reference row adjacent to the current processing block or the reference column adjacent to the current processing block; obtaining, based on the second reference sample set, a prediction value of the current processing block; and performing, based on the prediction value, intra prediction on the current processing block.

Abstract: A method for colour component prediction, an encoder, a decoder and a storage medium are provided. The method includes that: prediction parameters of a current block are determined, the prediction parameters including a prediction mode parameter and a size parameter of the current block; when the prediction mode parameter indicates that a Matrix-based Intra Prediction (MIP) mode is adopted to determine an intra prediction value of the current block, an MIP weight matrix of the current block, a shift factor of the current block and an MIP input sample matrix of the current block are determined; and the intra prediction value of the current block is determined according to the MIP weight matrix, the shift factor and the MIP input sample matrix.

Abstract: Processing methods for motion compensation, an encoder, and a decoder are provided. The method includes the following. Determine a search position constellation with a point pointed by an initial motion vector as a center point, where the search position constellation includes N directions, search for at least one search point by using at least one type of step lengths in the directions, where the at least one search point at least includes at least one search point in diagonal directions. Search for at least one search position from the search position constellation based on a preset range coverage rule, where the preset range coverage rule is to arrange search points in the directions for search. Obtain a new motion vector according to the at least one search position, and perform motion compensation based on the new motion vector to obtain a prediction value of a coding unit (CU).

Abstract: An encoding method, a decoding method, and a decoder are provided. The method includes the following. A prediction parameter of a current block is determined, where the prediction parameter includes a prediction mode parameter. Neighbouring sample values of the current block are obtained and matrix-based intra prediction (MIP) input sample values of the current block are determined according to the neighbouring sample values of the current block, when the prediction mode parameter indicates that an MIP mode is used to determine an intra prediction value of a chroma component of the current block. An MIP prediction value of the chroma component of the current block is determined according to the MIP input sample values, an MIP weighting matrix, and a shifting parameter. The intra prediction value of the chroma component of the current block is determined by filtering the MIP prediction value.

Abstract: An encoding method, a decoding method, and a decoder are provided. The method includes the following. A prediction parameter of a current block is determined, where the prediction parameter includes a prediction mode parameter. Neighbouring sample values of the current block are obtained and matrix-based intra prediction (MIP) input sample values of the current block are determined according to the neighbouring sample values of the current block, when the prediction mode parameter indicates that an MIP mode is used to determine an intra prediction value of a chroma component of the current block. An MIP prediction value of the chroma component of the current block is determined according to the MIP input sample values, an MIP weighting matrix, and a shifting parameter. The intra prediction value of the chroma component of the current block is determined by filtering the MIP prediction value.