Abstract: Embodiments of the present disclosure provide methods, apparatuses and computer storage media for video processing. One example method comprises determining, during a conversion between a current video block of a video and a bitstream of the video, at least one set of motion candidates for the current video block, each motion candidate comprising predicted motion information determined from neighboring video blocks of the current video block; determining, based on a template of the current video block and from the at least one set of motion candidates, a target motion candidate for the current video block by using a template matching cost rule; and performing the conversion based on the target motion candidate.

Abstract: Devices, systems and methods for the simplification of sub-block motion candidate lists for video coding are described. In a representative aspect, a method for video processing includes determining, during a conversion between a current block and a bitstream representation of the current block, a temporal motion vector prediction candidate for a sub-block of the current block. The temporal motion vector prediction candidate is completely determined based on K neighboring blocks of the current block, K being a positive integer. The method also includes performing the conversion based on the temporal motion vector prediction candidate for the sub-block.

Abstract: Methods and apparatus for video processing are described. The processing may include video encoding, video decoding or video transcoding. An example video processing method includes performing a conversion between a video comprising one or more pictures and a bitstream of the video according to a format rule, and wherein the format rule specifies that, in response to satisfying one or more conditions, a syntax element indicating whether a first syntax structure providing a profile, a tier and a level information and a second syntax structure providing decoded picture buffer information are present in a sequence parameter set is set to be equal to 1 to indicate that the first syntax structure and the second syntax structure are present in the sequence parameter set.

Abstract: Devices, systems, and methods for digital video coding, which includes inter prediction with refinement, are described. An exemplary method of video processing includes determining to use, for a conversion between a current block of a video and a bitstream representation of the video, a first linear optimization model for the conversion using a first coding mode, the first linear optimization model being derived from a second linear optimization model that is used for the conversion using a second coding mode, and performing, based on the determining, the conversion. Another exemplary method of video processing includes determining to use, for a conversion between a current block of a video and a bitstream representation of the video, a gradient value computation algorithm for a bi-directional optical flow tool, and performing, based on the determining, the conversion.

Abstract: Methods, systems and devices for implementing adaptive color transform (ACT) and block based delta pulse code modulation (BDPCM) during image/video encoding or decoding are described. An example method of video processing includes determining, for a conversion between a current video unit of a video that is a chroma video unit and a bitstream representation of the video, whether a block-based delta pulse code modulation (BDPCM) mode is available based on a rule, and performing the conversion based on the determining. The rule is based on whether an adaptive color transform (ACT) mode is used for coding the current video unit and/or whether the BDPCM mode is used for coding a luma video unit corresponding to the current video unit.

Abstract: Several techniques for video encoding and video decoding are described. One example method includes performing a conversion between a block of a video and a bitstream of the video according to a rule. The rule specifies that whether a syntax flag indicating whether transform skip residual coding is enabled at a video unit level is present in the bitstream is based on values of a first syntax element indicating usage of sign data hiding in the video unit and a second syntax element indicating usage of dependent quantization in the video unit.

Abstract: Video processing, including video coding, video decoding and video transcoding, is described. One example method includes performing a conversion between a video comprising a video picture and a bitstream of a video according to a rule, where the rule specifies that syntax elements indicate a first width and a first height of a scaling window for the video picture, and where the rule specifies that a range of permissible values for the syntax elements include values greater than or equal to two times a second width of the video picture and two times a second height of the video picture.

Abstract: A method of video processing includes determining, for a conversion between a current block of a video and a coded representation of the video, whether a syntax element indicating usage of a skip mode for an intra-block copy (IBC) coding model is included in the coded representation according to a rule that specifies that signaling of the syntax element is based on a dimension of the current block and/or a maximum allowed dimension for a block that is coded using the IBC coding model. The method also includes performing the conversion based on the determining.

Abstract: Devices, systems and methods related to digital video coding, and specifically, to signaling of slice types in video picture headers are described. One example method of video processing includes performing a conversion between a video including one or more video pictures including one or more slices and a bitstream of the video, wherein the bitstream conforms to a format rule, and wherein the format rule specifies that for a video picture of the one or more video pictures having all slices coded as I slices, P slice and B slice related syntax elements are omitted from a picture header for the video picture.

Abstract: A screen content processing method includes: dividing screen content into a plurality of areas; detecting pixel similarity between a first target area of a current frame of the screen content and a second target area of a previous frame of the screen content; using a pixel hash table of the second target area as a pixel hash table of the first target area if the similarity satisfies a first detection result; calculating pixel hash values of the first target area to establish a pixel hash table if the similarity satisfies a second detection result; traversing, according to a pixel hash table of an area to be coded in the first target area of the current frame, pixel hash tables of reference areas and performing intra block copy processing or hash motion estimation processing, to complete screen content processing for the first target area of the current frame.

Abstract: A video processing method includes performing a conversion between a video comprising a video unit and a bitstream of the video according to a rule. The rule specifies whether or how to include, in an adaptation parameter set (APS), information related to a scaling list of the video is based on a first syntax element. The first syntax element indicates whether the APS includes chroma component related syntax elements and is independent of one or more syntax elements in a sequence parameter set (SPS).

Abstract: Methods, systems, apparatus for video processing are described. A method for processing video includes performing a conversion between a video and a bitstream of the video according to a format rule, and wherein the format rule specifies whether a syntax element in a sequence parameter set (SPS) based on a value of a general constraint flag.

Abstract: Transform parameter derivation based on block partition is described. In an exemplary aspect, a method for video processing includes determining, for a conversion between a first block of video and a bitstream representation of the first block of video, whether a use of non-power-of-two partition trees (NPT-T) is enabled or disabled, wherein the NPT-T includes splitting the first block to multiple smaller sized child blocks of the first block, and at least one child block's width and/or height have a dimension that is a non-power-of-two integer; and performing the conversion based on the NPT-T in response to the determination that the NPT-T is enabled.

Abstract: Methods, systems, and devices for coding or decoding video wherein the picture partition mode is based on block size are described. An example method for video processing includes using a dimension of a virtual pipeline data unit (VPDU) used for a conversion between a video comprising one or more video regions comprising one or more video blocks and a bitstream representation of the video to perform a determination of whether a ternary-tree (TT) or a binary tree (BT) partitioning of a video block of the one or more video blocks is enabled, and performing, based on the determination, the conversion, wherein the dimension is equal to VSize in luma samples, wherein dimensions of the video block are CtbSizeY in luma samples, wherein VSize=min(M, CtbSizeY), and wherein M is a positive integer.

Abstract: A method of video processing includes determining, for a conversion between a current block in a video region of a video and a coded representation of the video, that splitting the current block into multiple transform units is permitted based on a characteristic of the current block. A signaling of the splitting is omitted in the coded representation. The method also includes performing the conversion based on the determining.

Abstract: Techniques for implementing video processing techniques are described. In one example implementation, a method of video processing includes determining, for a conversion between a current block of a video and a bitstream representation of the video, a manner in which coding information of the current block is represented in the bitstream representation in part based on whether a condition associated with a size of the current block is satisfied. The method also includes performing the conversion based on the determining.

Abstract: Devices, systems and methods for digital video coding, which includes context modeling and multiple transform matrix selection, are described. An exemplary method for video processing includes determining, for a conversion between a current video block of a video and a bitstream representation of the video, that an indication of a transform type in a multiple transform selection (MTS) operation is excluded from the bitstream representation, and wherein the current video block is coded using an intra block copy mode, and performing the conversion, wherein the indication is in a sequence parameter set, a picture parameter set, a tile group header, a slice header, a picture header, a tile header, a coding tree unit row, or a video data unit, and wherein the MTS operation includes using a transform from a plurality of predefined transform candidates for transforming a prediction error of the current video block during the conversion.

Abstract: A deep machine-learning approach is used for medical image fusion by a medical imaging system. This one approach may be used for different applications. For a given application, the same deep learning is used but with different application-specific training data. The resulting deep-learnt classifier provides a reduced feature vector in response to input of intensities of one image and displacement vectors for patches of the one image relative to another image. The output feature vector is used to determine the deformation for medical image fusion.

Abstract: A method for video processing is provided. The method includes determining, for a conversion between a current video block of a video that is a chroma block and a coded representation of the video, multiple sets of parameters, wherein each set of parameters defines a cross-component linear model (CCLM) and is derived from a corresponding group of chroma samples at corresponding chroma sample positions; determining, based on the multiple sets of parameters, parameters for a final CCLM; and performing the conversion based on the final CCLM.