Scaling list parameter-based video or image coding
According to the disclosure of the present document, scaling list data transmitted from an adaptation parameter set (APS) can be signaled through a hierarchical structure. In addition, by setting a limit on the scaling list data transmitted from the APS, it is possible to reduce the amount of data which has to be signaled for video/image coding, and facilitate implementation.
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 quantized transform coefficients for the current block based on the residual information;
deriving transform coefficients based on the quantized transform coefficients;
deriving residual samples based on the transform coefficients; and
generating reconstruction samples based on the prediction samples and the residual samples,
wherein the transform coefficients are derived by performing a dequantization process on the quantized transform coefficients based on scaling list data, and
wherein the image information includes an adaptation parameter set (APS), and
wherein the APS is identified based on APS ID information related to an identifier for the APS, and
wherein the APS includes the scaling list data based on APS type information for APS parameters included in the APS, and
wherein a range of values of the APS ID information is determined based on the APS type information.
2. The image decoding method of claim 1 , wherein the APS type information includes an APS type for an ALF including adaptive loop filter (ALF) parameters, an APS type for luma mapping with chroma scaling (LMCS) including LMCS parameters, or an APS type for a scaling list including parameters of the scaling list data.
3. The image decoding method of claim 2 , wherein a range of values of the APS ID information has a range from 0 to 3 or from 0 to 7 based on the APS type information related to one of the APS type for the ALF, the APS type for the LMCS, or the APS type for the scaling list.
4. The image decoding method of claim 1 ,
wherein the image information includes header information,
wherein the header information includes APS ID information related to scaling list data, and
wherein the scaling list data is obtained from the APS by identifying the APS based on the APS ID information of the header information.
5. The image decoding method of claim 4 ,
wherein the image information includes a sequence parameter set (SPS),
wherein the SPS includes first enabled flag information for indicating whether the scaling list data is used, and
wherein the header information includes the APS ID information related to the scaling list data based on the first enabled flag information related to indicating that the scaling list data is used.
6. The image decoding method of claim 5 ,
wherein the header information includes second enabled flag information for indicating whether the scaling list data is used in a picture or a slice,
wherein the header information includes the second enabled flag information based on the first enabled flag information of the SPS, and
wherein the header information includes the APS ID information related to the scaling list data based on the second enabled flag information.
7. The image decoding method of claim 1 , wherein deriving the transform coefficients comprises:
deriving a scaling matrix based on the scaling list data;
deriving a scaling factor based on the scaling matrix; and
deriving the transform coefficients by applying the dequantization based on the scaling factor.
8. An image encoding method performed by an encoding apparatus, comprising:
deriving prediction samples for a current block based on prediction mode information;
deriving residual samples based on the prediction samples;
deriving transform coefficients based on the residual samples;
deriving quantized transform coefficients through a quantization process based on the transform coefficients; and
encoding image information including residual information generated based on the quantized transform coefficients and the prediction mode information,
wherein the image information includes an adaptation parameter set (APS),
wherein the APS is identified based on APS ID information related to an identifier of the APS,
wherein the APS includes scaling list data based on APS type information for APS parameters included in the APS, and
wherein a range of values of the APS ID information is determined based on the APS type information.
9. The image encoding method of claim 8 , wherein the APS type information includes an APS type for an ALF including adaptive loop filter (ALF) parameters, an APS type for luma mapping with chroma scaling (LMCS) including LMCS parameters, or an APS type for a scaling list including parameters of the scaling list data.
10. The image encoding method of claim 9 , wherein a range of values of the APS ID information has a range from 0 to 3 or from 0 to 7 based on the APS type information related to one of the APS type for the ALF, the APS type for the LMCS, or the APS type for the scaling list.
11. The image encoding method of claim 8 ,
wherein the image information includes header information,
wherein the header information includes APS ID information related to scaling list data, and
wherein the APS including the scaling list data is identified based on the APS ID information of the header information.
12. The image encoding method of claim 11 ,
wherein the image information includes a sequence parameter set (SPS),
wherein the SPS includes first enabled flag information for indicating whether the scaling list data is used, and
wherein the header information includes the APS ID information related to the scaling list data based on the first enabled flag information related to indicating that the scaling list data is used.
13. The image encoding method of claim 12 ,
wherein the header information includes second enabled flag information for indicating whether the scaling list data is used in a picture or a slice,
wherein the header information includes the second enabled flag information based on the first enabled flag information of the SPS, and
wherein the header information includes the APS ID information related to the scaling list data based on the second enabled flag information.
14. The image encoding method of claim 8 , wherein slices within one picture refer to the APS including the scaling list data having an identical value of the APS ID information.
15. A non-transitory computer-readable digital storage medium storing a bitstream generated by an image encoding method, the method comprising:
deriving prediction samples for a current block based on prediction mode information;
deriving residual samples based on the prediction samples;
deriving transform coefficients based on the residual samples;
deriving quantized transform coefficients through a quantization process based on the transform coefficients; and
encoding image information including residual information generated based on the quantized transform coefficients and the prediction mode information to generate the bitstream,
wherein the image information includes an adaptation parameter set (APS),
wherein the APS is identified based on APS ID information related to an identifier of the APS,
wherein the APS includes scaling list data based on APS type information for APS parameters included in the APS, and
wherein a range of values of the APS ID information is determined based on the APS type information.
16. A transmission method of data for an image, the method comprising:
obtaining a bitstream for the image, wherein the bitstream is generated based on deriving prediction samples for a current block based on prediction mode information, deriving residual samples based on the prediction samples, deriving transform coefficients based on the residual samples, deriving quantized transform coefficients through a quantization process based on the transform coefficients, encoding image information including residual information generated based on the quantized transform coefficients and the prediction mode information; and
transmitting the data comprising the bitstream,
wherein the image information includes an adaptation parameter set (APS),
wherein the APS is identified based on APS ID information related to an identifier of the APS,
wherein the APS includes scaling list data based on APS type information for APS parameters included in the APS, and
wherein a range of values of the APS ID information is determined based on the APS type information.