Methods and systems for generating an interpolated reshaping function for the efficient coding of high-dynamic range images are provided. The interpolated reshaping function is constructed based on a set of pre-computed basis reshaping functions. Interpolation schemes are derived for pre-computed basis reshaping functions represented as look-up tables, multi-segment polynomials, or matrices of coefficients in a multivariate, multi-regression representation. Encoders and decoders using asymmetric reshaping and interpolated reshaping functions for mobile applications are also presented.

A method decodes one or more code words in a loop that is run N times by decoding an indication of whether a picture is a long-term picture or not and deriving a positive integer K[i]>0 for each long-term picture. An indicator value V[i] is derived for each long-term picture by subtracting the value of the positive integer K[i] from a picture indicator value P of the current picture. For each of the indicator values V[i], the indicator value V[i] is compared with values associated with pictures stored in the DPB. The method keeps the pictures stored in the DPB marked as short-term or long-term for which there is a match with one of the indicator values V[i] in the DPB as long-term pictures, and marks long-term pictures for which there is no match with any indicator value V[i] as unused for reference in the DPB.

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 image coding method includes: performing context arithmetic coding to consecutively code (i) first information indicating whether or not to perform sample adaptive offset (SAO) processing for a first region of an image and (ii) second information indicating whether or not to use, in the SAO processing for the first region, information on SAO processing for a region other than the first region, the context arithmetic coding being arithmetic coding using a variable probability, the SAO processing being offset processing on a pixel value; and performing bypass arithmetic coding to code other information which is information on the SAO processing for the first region and different from the first information or the second information, after the first information and the second information are coded, the bypass arithmetic coding being arithmetic coding using a fixed probability.

An image coding method includes coding a motion vector difference indicating a difference between the motion vector and a predicted motion vector, wherein the coding includes: coding a first portion that is a part of a first component which is one of a horizontal component and a vertical component of the motion vector difference; coding a second portion that is a part of a second component which is different from the first component and is the other one of the horizontal component and the vertical component; coding a third portion that is a part of the first component and is different from the first portion; coding a fourth portion that is a part of the second component and is different from the second portion; and generating a code string which includes the first portion, the second portion, the third portion, and the fourth portion in the stated order.

A video coder determines of shift values based on the dynamic range of a sum of absolute values of neighboring transform coefficients. The shift value may then be used to extend possible values of a Rice parameter used to binarize a syntax element related to a currently coded transform coefficient.

An image coding method includes coding a motion vector difference indicating a difference between the motion vector and a predicted motion vector, wherein the coding includes: coding a first portion that is a part of a first component which is one of a horizontal component and a vertical component of the motion vector difference; coding a second portion that is a part of a second component which is different from the first component and is the other one of the horizontal component and the vertical component; coding a third portion that is a part of the first component and is different from the first portion; coding a fourth portion that is a part of the second component and is different from the second portion; and generating a code string which includes the first portion, the second portion, the third portion, and the fourth portion in the stated order.

An image decoding method according to the present document comprises a step for performing inverse first-order transform and inverse non-separable transform on a residual sample. The inverse non-separable transform is performed on the basis of a transform index indicating a predetermined transform kernel matrix, the inverse first-order transform is performed on the basis of a multiple transform selection (MTS) index indicating MTS for a horizontal transform kernel and a vertical transform kernel, and a syntax element bin string for the transform index is derived on the basis of first context information when a tree type for a split structure of a target block is not a single tree type and is derived on the basis of second context information when the tree type is the single tree type.

This disclosure describes video encoding and video decoding techniques for encoding and decoding video data in a chroma intra prediction mode. The techniques may improve the encoding and decoding process by simplifying aspects of the encoding and decoding process and by reducing a number of binarization tables used for the encoding and decoding. Moreover, reducing the number binarization tables may, in turn, reduce the amount of memory needed in an encoder device or decoder device to perform the video encoding or decoding process.

This disclosure provides methods, devices, and systems for data compression. The present implementations more specifically relate to lossless data compression techniques that combine entropy coding with run-length encoding of zeroes. In some aspects, an encoder may obtain a sequence of integer values representing a frame of data and may iteratively scan the sequence for runs of zeros. During each iteration of the scan, the encoder may increment a count value (N) if the current integer value is equal to zero or, if the current integer value is not equal to zero, output a pattern of bits representing the current count value or the current integer value. In some implementations, the pattern of bits may include a codeword associated with an entropy encoding scheme. More specifically, the encoder may encode the current integer value as the codeword if N>0 and may encode the current count value as the codeword if N=0.