Act residual-based image or video coding
According to the disclosure of the present document, a residual sample can be derived by applying adaptive color transform (ACT) with respect to a current block on the basis of ACT-associated information, wherein the residual sample is derived by being clipped on the basis of a clipping boundary, wherein the clipping boundary is determined on the basis of a bit depth.
1. An image decoding method performed by a decoding apparatus, the method comprising:
obtaining image information including adaptive color transform (ACT)-related information from a bitstream;
deriving a residual sample by applying ACT for a current block based on the ACT-related information; and
generating a reconstructed sample based on the residual sample,
wherein the ACT-related information includes information on whether to apply the ACT to the current block,
wherein based on the ACT-related information on applying the ACT to the current block, the residual sample is derived by clipping based on a clipping range,
wherein the clipping range is determined based on a bit depth (BitDepth),
wherein the clipping range has a value between a maximum value and a minimum value derived based on a value obtained by increasing the bit depth by 1, and
wherein the maximum value of the clipping range is equal to (1<<(BitDepth+1))−1.
2. An image encoding method performed by an encoding apparatus, the method comprising:
generating adaptive color transform (ACT)-related information for a current block;
deriving a residual sample by applying ACT to the current block based on the ACT-related information;
generating residual information on the residual sample; and
encoding image information including the ACT-related information and the residual information,
wherein the ACT-related information includes information on whether to apply the ACT to the current block,
wherein based on the ACT-related information on applying the ACT to the current block, the residual sample is derived by clipping based on a clipping range,
wherein the clipping range is determined based on a bit depth (BitDepth),
wherein the clipping range has a value between a maximum value and a minimum value derived based on a value obtained by increasing the bit depth by 1, and
wherein the maximum value of the clipping range is equal to (1<<(BitDepth+1))−1.
3. A non-transitory computer-readable storage medium storing a bitstream generated by the image encoding method of claim 2 .
4. A transmission method of data for an image, the transmission method comprising:
obtaining a bitstream for the image, wherein the bitstream is generated based on generating adaptive color transform (ACT)-related information for a current block, deriving a residual sample by applying ACT to the current block based on the ACT-related information, generating residual information on the residual sample, and encoding image information including the ACT-related information and the residual information; and
transmitting the data comprising the bitstream,
wherein the ACT-related information includes information on whether to apply the ACT to the current block,
wherein based on the ACT-related information on applying the ACT to the current block, the residual sample is derived by clipping based on a clipping range,
wherein the clipping range is determined based on a bit depth (BitDepth),
wherein the clipping range has a value between a maximum value and a minimum value derived based on a value obtained by increasing the bit depth by 1, and
wherein the maximum value of the clipping range is equal to (1<<(BitDepth+1))−1.