An image decoding method according to the present document comprises a step of deriving modified transform coefficients, wherein the step of deriving the modified transform coefficients comprises a step of setting an LFNST apply variable about whether to apply an LFNST on the basis of the tree type of the current block, a transform coefficient coding flag for each component of the current block, or a transform skip flag for each component of the current block, and can comprise a step of parsing an LFNST index on the basis of the value of the LFNST apply variable.

Methods for management of encoding complexity for image and video encoding, for example for algorithms belonging to the JPEG 2000 family of standards, where the encoding process targets a given compressed size (i.e. a total coded length) for the image or for each frame of a video sequence. Described are a set of methods for complexity constrained encoding of HTJ2K code-streams, involving collection of local or global statistics for each sub-band (not for each code-block), generation of forecasts for the statistics of sub-band samples that have not yet been produced by spatial transformation and quantization processes, and the use of this information to generate a global quantization parameter, from which the coarsest bit-plane to generate in each code-block can be deduced. Coded length estimates can be generated in a manner that enables latency and memory to be separately optimized against encoded image quality, while maintaining low computational complexity.

According to the disclosure of the present document, chroma quantization parameter offset-related information can be signaled through palette coding syntax, and index information of a chroma quantization parameter offset list can be efficiently parsed/signaled on the basis of information on the number of entries in the chroma quantization parameter offset list. Accordingly, bits needing to be signaled for video/image coding can be reduced, and the coding efficiency can be improved.

Decoding a coding unit of a coding tree from a coding tree unit, the coding unit having a luma colour channel and at least one chroma colour channel. Decoding a luma transform skip flag for a luma transform block; decoding at least one chroma transform skip flag, each chroma transform skip flag corresponding to one of at least one chroma transform block; determining a secondary transform index by decoding a secondary transform index if at least one of the luma transform skip flag and the at least one chroma transform skip flags indicates that a transform of the transform block is not to be skipped, and determining the secondary transform index to indicate that a secondary transform is not to be applied if all of the luma transform skip flag and the at least one chroma transform skip flags indicate transforms of the respective transform blocks are to be skipped.

Control over encoding of a quantization parameter is appropriately enabled with not only square sub-blocks but also rectangular sub-blocks by using a quantization control size adaptively according to a shape of sub-blocks, with the result that coding efficiency is improved.

The problem when the use range of images for use in intra-prediction is expanded is that the requirement for line buffer size increases depending on the range of expansion, and, in order to solve this problem, the use range of imaged for use in intra-prediction is adaptively controlled. The intra-prediction apparatus 100 of the present invention has, a control section 115 that controls, based on the relationship between the position of a candidate image for use in intra-prediction for a block to be processed and the position of the unit where the block to be processed belongs, the partial range for use for intra-prediction beyond the end portion of the unit in a predetermined direction in the use range of the image for use for intra-prediction to be equal to or less than a predetermined maximum range.

A video decoding method performed by a decoding apparatus according to the present document may comprise the steps of: acquiring, from a bitstream, information indicating a level value of a transform coefficient in a current block; deriving a Rice parameter for the information indicating the level value of the transform coefficient, on the basis of a quantization parameter of the current block; deriving a bin string for the information indicating the level value of the transform coefficient, on the basis of the Rice parameter; and deriving the level value of the transform coefficient on the basis of the bin string.

A method of video processing is provided that includes performing a conversion between a block of a video and a bitstream of the video. The bitstream conforms to a formatting rule specifying that a size of a merge estimation region (MER) is indicated in the bitstream and the size of the MER is based on a dimension of a video unit. The MER comprises a region used for deriving a motion candidate for the conversion.

A versatile video coding (VVC) method includes obtaining a plurality of video sources; encoding the plurality of video sources into a bitstream including a plurality of independent layers corresponding to the plurality of video sources; generating signaling information on the plurality of independent layers and integrating the signaling information with the bitstream; and transferring the bitstream for decoding processing, wherein the signaling information is to be used in the decoding process to enable a single decoder instance to decode the plurality of independent layers similar to a single-layer bitstream. The signaling information includes at least a video parameter set (VPS), and the VPS includes a flag inbl_one_pic_per_poc_flag equal to 1, which specifies that the bitstream contains independent layers and there is one and only one coded picture with a particular picture order count (POC) value in a same coded video sequence (CVS) among all layers.

An image processing apparatus decodes encoded RAW data that includes subband data being encoded with lossy encoding scheme, and determines one of a plurality of classifications based on the decoded subband data, wherein the plurality of classifications are based on a feature of an image. The apparatus also obtains correction data corresponding to the determined classification, and corrects recomposed data, which is obtained by applying frequency recomposition to the decoded subband data, based on the correction data, in order to obtain the corrected data as decoded RAW data.