Disclosed herein is an intra prediction method including: deriving neighbor prediction mode information from a left neighbor prediction mode and an upper neighbor prediction mode; deriving an intra prediction mode for a decoding target unit by using the derived neighbor prediction mode information; and performing intra prediction on the decoding target unit based on the intra prediction mode. According to exemplary embodiments of the present invention, image encoding/decoding efficiency can be improved.

Disclosed herein is an intra prediction method including: deriving neighbor prediction mode information from a left neighbor prediction mode and an upper neighbor prediction mode; deriving an intra prediction mode for a decoding target unit by using the derived neighbor prediction mode information; and performing intra prediction on the decoding target unit based on the intra prediction mode. According to exemplary embodiments of the present invention, image encoding/decoding efficiency can be improved.

An encoder includes circuitry and memory coupled to the circuitry. The circuitry, in operation, for each coefficient of a plurality of coefficients included in a block, determines a base level relating to Context-Based Adaptive Binary Arithmetic Coding (CABAC) for the coefficient, and encodes an absolute value of the coefficient. In determining the base level, when one or more flags are used in encoding the absolute value of the coefficient, the base level is determined to be a first value, and when one or more flags are not used in the encoding, the base level is determined to be a second value that is smaller than the first value. In encoding the absolute value of the coefficient, when one or more flags are not used, a rice parameter is determined based on the base level which is equal to the second value, and the coefficient is binarized using the rice parameter.

In a method of decoding, coded information of a block is received from a coded video bitstream. The coded information indicates that the block is partitioned based on a geometry partition mode (GPM) into a first part and a second part and inter predicted based on merge mode with motion vector difference (MMVD). That a motion vector for the first part of the block partitioned by GPM is not identical to a motion vector for the second part of the block partitioned by GPM is determined. The block is further reconstructed based on the motion vector for the first part of the block and the motion vector for the second part of the block.

Methods, systems and apparatus for video processing are described. One example video processing method includes performing a conversion between a video including a video region and a bitstream of the video according to a rule, wherein the rule specifies that an adaptive loop filtering operation is allowed for the video region in response to an absence of one or more adaptation parameter set (APS) network abstraction layer (NAL) units that include adaptive loop filtering data.

A video decoding method includes obtaining a size of a coding block of a video image frame, and decoding a bitstream of the coding block to obtain a value of a range variable associated with a SRCC scan region of the coding block. The range variable includes a width range variable and a height range variable. Each of the width range variable and the height range variable are obtained by comparing a prefix value to one or more predefined value intervals. The method further includes determining a horizontal coordinate of boundary coordinates of the SRCC scan region according to a difference between the width of the coding block and the width range variable and determining a vertical coordinate of the boundary coordinates of the SRCC scan region according to a difference between the height of the coding block and the height range variable.

An image decoding method according to the present document comprises the steps of: receiving a bitstream including residual information; deriving a quantized transform coefficient for a current block on the basis of the residual information included in the bitstream; deriving a residual sample for the current block on the basis of the quantized transform coefficient; and generating a reconstructed picture on the basis of the residual sample for the current block, wherein the residual information may be derived via different syntax elements depending on whether a transform has been applied to the current block.

An example device for coding (encoding and/or decoding) video data includes a memory configured to store video data; and one or more processors implemented in circuitry and configured to: calculate a sum of absolute values of a plurality of neighboring coefficients to a current coefficient for a current block of video data; calculate a base level offset value according to at least one of a bit depth for the video data or a slice type for a slice including the current block; calculate a normalized value for the sum of absolute values using the base level offset value; and code the current coefficient using the normalized value for the sum of absolute values.

Decoding a bitset, each bit of the bitset corresponding to a respective value in a range of a minimum value to a maximum value, includes decoding, from a compressed bitstream, indexes of bits of the bitset, each bit of the bits having a first value. Decoding the bitset also includes setting all other bits of the bitset not decoded from the compressed bitstream to a second value. Decoding the indexes of bits of the bitset includes decoding a number of the indexes of the bits of the bitset, decoding a first index of the indexes in a first range having a first lower bound and a first upper bound, and decoding a last index of the indexes in a second range having a second lower bound and a second upper bound.

An image decoding method according to the present document comprises the steps of: receiving a bitstream including residual information; deriving a quantized transform coefficient for a current block on the basis of the residual information included in the bitstream; deriving a residual sample for the current block on the basis of the quantized transform coefficient; and generating a reconstructed picture on the basis of the residual sample for the current block, wherein the residual information may be derived via different syntax elements depending on whether a transform has been applied to the current block.