A decoder comprises circuitry and memory. The circuitry, using the memory, in operation, determines a number of first pixels and a number of second pixels used in a deblocking filter process, wherein the first pixels are located at an upper side of a block boundary and the second pixels are located at a lower side of the block boundary, and performs the deblocking filter process on the block boundary. The number of the first pixels and the number of the second pixels are selected from among candidates, wherein the candidates include at least 4 and M larger than 4. Response to a location of the block boundary being a predetermined location, the number of the first pixels used in the deblocking filter process is limited to be 4.

A decoder comprises circuitry and memory. The circuitry, using the memory, in operation, determines a number of first pixels and a number of second pixels used in a deblocking filter process, wherein the first pixels are located at an upper side of a block boundary and the second pixels are located at a lower side of the block boundary, and performs the deblocking filter process on the block boundary. The number of the first pixels and the number of the second pixels are selected from among candidates, wherein the candidates include at least 4 and M larger than 4. Response to a location of the block boundary being a predetermined location, the number of the first pixels used in the deblocking filter process is limited to be 4.

A method, computer program, and computer system is provided for video encoding and decoding. Video data including one or more frames is received. One or more quantization parameters associated with the received video data are determined for frame generation or enhancement of a target frame from among the one or more frames. The video data is decoded based on the determined quantization parameters.

A method is disclosed. In the method, color differences are calculated between a current video frame and a motion predicted version of the current video frame based on a human visual system's ability to perceive the color differences. Also, information in a difference frame is discarded based on the color differences. The difference frame includes differences between the current video frame and the motion predicted version of the current video frame.

A method is disclosed. In the method, color differences are calculated between a current video frame and a motion predicted version of the current video frame based on a human visual system's ability to perceive the color differences. Also, information in a difference frame is discarded based on the color differences. The difference frame includes differences between the current video frame and the motion predicted version of the current video frame.

Provided is a video decoding method of applying a deblocking filter to neighboring pixels adjacent to a boundary of a current block, the video decoding method including selecting a deblocking filter to be applied to the neighboring pixels from among a plurality of deblocking filters according to pixel values of the neighboring pixels and a size of the current block, and applying the selected deblocking filter to the neighboring pixels, wherein the plurality of deblocking filters include three or more deblocking filters having different ranges of neighboring pixels to which deblocking filtering is applied.

Provided is a video decoding method of applying a deblocking filter to neighboring pixels adjacent to a boundary of a current block, the video decoding method including selecting a deblocking filter to be applied to the neighboring pixels from among a plurality of deblocking filters according to pixel values of the neighboring pixels and a size of the current block, and applying the selected deblocking filter to the neighboring pixels, wherein the plurality of deblocking filters include three or more deblocking filters having different ranges of neighboring pixels to which deblocking filtering is applied.

An image decoding method according to the present disclosure presents indication information related to whether deblocking parameters for a deblocking filtering procedure exist in a picture header or a slice header.

An image decoding method according to the present disclosure presents indication information related to whether deblocking parameters for a deblocking filtering procedure exist in a picture header or a slice header.

Methods and apparatus for video processing are disclosed. The processing may include video encoding, video decoding, or video transcoding. One example method includes performing a conversion between a video including a picture including one or more slices and a bitstream of the video. The conversion conforms to a rule that specifies that whether a deblocking filter is applied to the one or more slices referring to a picture parameter set is based at least on a first syntax element included in the picture parameter set. The first syntax element indicates whether the deblocking filter is disabled for the picture.