A method and apparatus for inter-view ARP (advanced residual prediction) are disclosed. According to one embodiment, a first inter-view reference block of a first inter-view reference picture in a first reference view is determined using a current MV (motion vector) of the current block in an inter-view direction. A first MV associated with the first inter-view reference block is derived. If the first MV points to a second inter-view reference picture in a second reference view, the derived MV is set to a default derived MV. A second temporal reference block in the second temporal reference picture corresponding to the current block is identified using the derived MV. An inter-view residual predictor corresponding to the difference between a second inter-view reference block in the first reference view and the second temporal reference block is generated and used as a predictor for the current inter-view residual of the current block.

A method and apparatus for inter-view ARP (advanced residual prediction) are disclosed. According to one embodiment, a first inter-view reference block of a first inter-view reference picture in a first reference view is determined using a current MV (motion vector) of the current block in an inter-view direction. A first MV associated with the first inter-view reference block is derived. If the first MV points to a second inter-view reference picture in a second reference view, the derived MV is set to a default derived MV. A second temporal reference block in the second temporal reference picture corresponding to the current block is identified using the derived MV. An inter-view residual predictor corresponding to the difference between a second inter-view reference block in the first reference view and the second temporal reference block is generated and used as a predictor for the current inter-view residual of the current block.

A motion vector prediction method includes parsing a bitstream to obtain an index value of a candidate motion vector list and constructing the candidate motion vector list that includes. candidate motion vectors of K control points of a current block. The candidate motion vectors of K control points are obtained based on a 2N-parameter affine transform model used for a neighboring block of the current block, where N and K are integers greater than or equal to 2 and less than or equal to 4 with N not being equal to K. The method further includes determining, in the candidate motion vector list, target candidate motion vectors of the K control points based on the index value and obtaining a predicted motion vector of each subblock of the current block based on the target candidate motion vectors of the K control points.

Disclosed herein are exemplary embodiments of innovations in the area of point cloud encoding and decoding. Example embodiments can reduce the computational complexity and/or computational resource usage during 3D video encoding by selectively encoding one or more 3D-point-cloud blocks using an inter-frame coding (e.g., motion compensation) technique that allows for previously encoded/decoded frames to be used in predicting current frames being encoded. Alternatively, one or more 3D-point-cloud block can be encoded using an intra-frame encoding approach. The selection of which encoding mode to use can be based, for example, on a threshold that is evaluated relative to rate-distortion performance for both intra-frame and inter-frame encoding. Still further, embodiments of the disclosed technology can use one or more voxel-distortion-correction filters to correct distortion errors that may occur during voxel compression. Such filters are uniquely adapted for the particular challenges presented when compressing 3D image data. Corresponding decoding techniques are also disclosed.

An encoder includes circuitry and memory. Using the memory, the circuitry: in an inter prediction mode in which an affine motion vector is calculated for each of sub-blocks constituting a current block of a picture in the video, based on motion vectors of neighboring blocks of the current block, changes a shape or size of the sub-block according to a variation in direction or variation in magnitude among the motion vectors of the neighboring blocks; calculates the affine motion vector for the sub-block having the shape or size changed; and performs the motion compensation for the sub-block having the shape or size changed.

A method of performing inter-picture prediction of a current picture of a video sequence is performed by at least one processor and includes determining whether the current picture uses a virtual reference picture, and based on the current picture being determined to use the virtual reference picture, generating, for the current picture, the virtual reference picture from neighboring reference pictures that are nearest neighbors to the virtual reference picture, storing the generated virtual reference picture in a decoded picture buffer, and adding the generated virtual reference picture to an active reference picture list. The method further includes performing the inter-picture prediction of the current picture, based on the active reference picture list to which the virtual reference picture is added.

A method for video processing is disclosed to include: determining, for a conversion between a coded representation of a current block of a video and the current block, a motion vector difference (MVD) precision to be used for the conversion from a set of allowed multiple MVD precisions applicable to a video region containing the current video block; and performing the conversion based on the MVD precision.

An encoder includes memory, and circuitry accessible to the memory. The circuitry accessible to the memory: determines whether OBMC is applicable to generation of a prediction image of a current block, according to whether BIO is to be applied to the generation of the prediction image of the current block; when BIO is to be applied to the generation of the prediction image of the current block, determines that OBMC is not applicable to the generation of the prediction image of the current block, and applies BIO to the generation of the prediction image of the current block without applying OBMC.

Disclosed herein is a method of decoding an image including determining whether a current block is in a bi-directional optical flow (BIO) mode, calculating gradient information of prediction samples of the current block when the current block is in the BIO mode, and generating a prediction block of the current block using the calculated gradient information, wherein the calculating of the gradient information of the prediction samples of the current block includes calculating the gradient information using at least one neighbor sample adjacent to the prediction samples.

A method of representing image data comprising a spatial pyramid data structure of order L, said method comprising: providing an initial representation of said image data, said representation comprising a set of lattices of level 0; connecting each said lattices of level 0 to said image data; performing L reduction steps each comprising: for each one of at least one current lattice of the current level, optionally blurring said current lattice; providing a plurality of down sampled sub-lattices of said current optionally blurred lattice, said at least one current lattice being the parent lattice of said respective plurality of down sampled sub-lattices; and connecting said plurality of down sampled sub-lattices to said respective parent lattice, wherein said plurality of down sampled sub-lattices of the current level, comprise the set of current lattices for the next level.