Abstract: This application discloses a point cloud encoding processing method and apparatus and a point cloud decoding processing method and apparatus. The point cloud encoding processing method of embodiments of this application includes: determining sparsity level information of a target point cloud; and in a case that the sparsity level information indicates the target point cloud being a sparse point cloud and a node to be encoded corresponding to the target point cloud satisfies an isolated point encoding condition, enabling an isolated point encoding mode.

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: Disclosed are a point cloud encoding and decoding method and device based on a two-dimensional regularization plane projection. The encoding method includes: acquiring original point cloud data; performing two-dimensional regularization plane projection on the original point cloud data to obtain a two-dimensional projection plane structure; obtaining a plurality of pieces of two-dimensional image information according to the two-dimensional projection plane structure; and encoding the plurality of pieces of two-dimensional image information to obtain code stream information.

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: An encoding method includes: obtaining original point cloud data; obtaining depth information of a point cloud based on the original point cloud data; establishing a relationship between the depth information and azimuth information of the point cloud; and predictively encoding the azimuth information of the point cloud by using the relationship between the depth information and the azimuth information of the point cloud, to obtain coded stream information.

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 point cloud data preprocessing method, a point cloud geometry coding method and apparatus, and a point cloud geometry decoding method and apparatus are disclosed. The preprocessing method includes: performing coordinate conversion on original point cloud data to obtain a representation of an original point cloud in a cylindrical coordinate system; unfolding the cylindrical coordinate system to obtain a two-dimensional structure; and performing regularization processing on the two-dimensional structure based on a geometric distortion measure to obtain a regularized structure. The coding method includes: performing predictive coding on preprocessed original point cloud data to obtain a geometric information bitstream.

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: Disclosed in the implementations of the present disclosure are a mapping method, an encoder, a decoder, and a computer storage medium. The method may include: determining an intra prediction mode used at the time of encoding or decoding a current block; mapping, if the intra prediction mode is a MIP mode, the MIP mode to a first non-MIP mode; and mapping, if the intra prediction mode is a non-MIP mode, the non-MIP mode to a second MIP mode.

Abstract: A method for coding includes: obtaining original point cloud data; creating an adaptive prediction list of the attribute information of the point cloud; selecting a prediction mode from the adaptive prediction list and predicting the attribute information of the point cloud, to obtain a predicted residual; and coding the prediction mode and the predicted residual, to obtain codestream information.

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: 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: 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: The present application discloses a point cloud encoding/decoding method and apparatus based on two-dimensional regularized plane projection. The encoding method includes: acquiring raw point cloud data; performing two-dimensional regularized plane projection on the raw point cloud data to obtain a two-dimensional projection plane structure; obtaining one or more pieces of two-dimensional graphic information based on the two-dimensional projection plane structure; and encoding the one or more pieces of two-dimensional graphic information to obtain bit stream information. In the present application, a strong correlation representation of a point cloud on a two-dimensional projection plane structure is obtained using a two-dimensional regularized plane projection technology, which highlights spatial correlation of the point cloud.

Abstract: A prediction decoding method, a prediction decoding apparatus, and a non-transitory computer storage medium are provided. The method includes the following. First multiple neighbouring reference samples of a coding block are determined, where the first multiple neighbouring reference samples include reference samples in a reference row or a reference column neighbouring the coding block. Positions corresponding to K reference samples are determined from a starting position of the reference row or the reference column, where K is a positive integer. Second multiple neighbouring reference samples are determined according to the determined positions corresponding to the K reference samples, where the second multiple neighbouring reference samples include neighbouring reference samples among the first multiple neighbouring reference samples. Prediction decoding is performed on the coding block according to the second multiple neighbouring reference samples.

Abstract: A prediction decoding method, a prediction decoding apparatus, and a non-transitory computer storage medium are provided. The method includes the following. First multiple neighbouring reference samples of a coding block are determined, where the first multiple neighbouring reference samples include reference samples in a reference row or a reference column neighbouring the coding block. Positions corresponding to K reference samples are determined from a starting position of the reference row or the reference column, where K is a positive integer. Second multiple neighbouring reference samples are determined according to the determined positions corresponding to the K reference samples, where the second multiple neighbouring reference samples include neighbouring reference samples among the first multiple neighbouring reference samples. Prediction decoding is performed on the coding block according to the second multiple neighbouring reference samples.

Abstract: A method for coding includes: obtaining original point cloud data; creating an adaptive prediction list of the depth information of the point cloud; and predictively coding the depth information of the point cloud based on the adaptive prediction list, to obtain codestream information. According to the present invention, an adaptively updated prediction list of the depth information is created, and an optimal prediction mode is selected from the list to predict the depth information of the point cloud.