Abstract: Methods and apparatus are provided for collaborative partition coding for region based filters. An apparatus includes a video encoder (100) for encoding image data for a plurality of regions in a picture. The video encoder (100) includes multiple filters for filtering the image data based on region partition information for the plurality of regions. The region partition information for the plurality of regions is shared between the multiple filters.

Abstract: A decoder includes memory and a processor coupled to the memory and configured to: generate a first coefficient value by applying a CCALF (cross component adaptive loop filtering) process to a first reconstructed image sample of a luma component; clip the first coefficient value such that the clipped first coefficient value is within a first range from ?27 to 27?1; generate a second coefficient value by applying an ALF (adaptive loop filtering) process to a second reconstructed image sample of a chroma component; clip the second coefficient value such that the clipped second coefficient value is within a second range different from the first range; generate a third coefficient value by adding the clipped first coefficient value to the clipped second coefficient value; and generate a third reconstructed image sample of the chroma component using the third coefficient value.

Abstract: An image decoding method, according to the present disclosure, enables: acquiring, from a bitstream, image information including prediction mode information and adaptive loop filter (ALF) information including alternative filter information for a chroma component of a current block; deriving prediction samples for the current block on the basis of the prediction mode information; generating reconstructed samples on the basis of the prediction samples; and generating modified reconstructed samples for the chroma component of the current block on the basis of the alternative filter information.

Abstract: A method for signalling an intra chroma prediction mode and a method for implementing the signalled intra chroma prediction mode, the intra chroma prediction mode taking an intropolation of previously predicted luma samples from neighboring blocks of video data to attain an intra chroma prediction of a current chroma prediction unit.