Scaling list parameter-based video or image coding
According to the disclosure of the present document, scaling list data and scaling list-related information may be hierarchically signaled, thereby enabling a reduction in data volume to be signaled for video/image coding and an increase in coding efficiency.
1 . An image decoding method performed by a decoding apparatus, the method comprising:
obtaining image information including prediction mode information and residual information from a bitstream;
deriving prediction samples for a current block based on the prediction mode information;
deriving residual samples for the current block based on the residual information; and
generating reconstructed samples based on the prediction samples and the residual samples;
wherein the deriving of the residual samples comprises:
deriving quantized transform coefficients based on the residual information;
deriving transform coefficients through a dequantization process for the quantized transform coefficients based on scaling list data; and
deriving the residual samples based on the transform coefficients,
wherein the scaling list data is obtained based on an adaptation parameter set (APS) included in the image information,
wherein the APS includes APS type information related to indicating that the APS is related to the scaling list data, wherein the APS includes the scaling list data based on the APS type information,
wherein in the dequantization process, the transform coefficients are derived by using a scaling matrix derived based on the scaling list data,
wherein the scaling list data includes scaling list delta coefficient information representing a difference between a current matrix coefficient and a previous matrix coefficient,
wherein a value of the scaling list delta coefficient information is in range of −128 to 127,
wherein the image information includes a sequence parameter set (SPS), and
wherein the SPS includes enabled flag information related to whether a scaling list is used or not.
2 . An image encoding method performed by an image encoding apparatus, the method comprising:
deriving prediction samples for a current block based on inter prediction or intra prediction;
generating prediction mode information of the current block;
deriving residual samples based on the prediction samples;
generating residual information based on the residual samples; and
encoding image information including the prediction mode information and the residual information;
wherein generating the residual information comprises:
deriving transform coefficients based on the residual samples;
deriving quantized transform coefficients through a quantization process for the transform coefficients; and
generating the residual information based on the quantized transform coefficients,
wherein scaling list data for the quantized transform coefficients is included in an adaptation parameter set (APS),
wherein the APS includes APS type information related to indicating that the APS is related to the scaling list data, wherein the APS includes the scaling list data based on the APS type information,
wherein the image information is encoded including the APS,
wherein the quantized transform coefficients are derived by using a scaling matrix derived based on the scaling list data,
wherein the scaling list data includes scaling list delta coefficient information representing a difference between a current matrix coefficient and a previous matrix coefficient,
wherein a value of the scaling list delta coefficient information is in range of −128 to 127,
wherein the image information includes a sequence parameter set (SPS), and
wherein the SPS includes enabled flag information related to whether a scaling list is used or not.
3 . A non-transitory computer-readable digital storage medium storing a bitstream generated by the method of claim 2 .
4 . A method for transmitting data for image information, the method comprising:
obtaining a bitstream of the image information including prediction mode information and residual information, wherein the bitstream is generated based on deriving prediction samples for a current block based on inter prediction or intra prediction, generating prediction mode information of the current block, deriving residual samples based on the prediction samples, generating residual information based on the residual samples and encoding the image information including the prediction mode information and the residual information; and
transmitting the data comprising the bitstream of the image information including the prediction mode information and the residual information,
wherein the residual information is generated based on deriving transform coefficients based on the residual samples, deriving quantized transform coefficients through a quantization process for the transform coefficients and generating the residual information based on the quantized transform coefficients,
wherein scaling list data for the quantized transform coefficients is included in an adaptation parameter set (APS),
wherein the APS includes APS type information related to indicating that the APS is related to the scaling list data, wherein the APS includes the scaling list data based on the APS type information,
wherein the image information is encoded including the APS,
wherein the quantized transform coefficients are derived by using a scaling matrix derived based on the scaling list data,
wherein the scaling list data includes scaling list delta coefficient information representing a difference between a current matrix coefficient and a previous matrix coefficient,
wherein a value of the scaling list delta coefficient information is in range of −128 to 127,
wherein the image information includes a sequence parameter set (SPS), and
wherein the SPS includes enabled flag information related to whether a scaling list is used or not.