Adaptive color space transform coding
An encoder system may include an analyzer that analyzes a current image area in an input video to select a transform. A selectable residue transformer, controlled by the analyzer, may perform the selectable transform on a residue image generated from the current image area and a predicted current image area, to generate a transformed residue image. An encoder may encode the transformed residue image to generate output data. The analyzer controls the encoder to encode information to identify the selectable transform and to indicate that the selectable transform for the current image area is different from a transform of a previous image area of the input video. A decoder system may include components appropriate for decoding the output data from the encoder system.
1. A system for video encoding comprising:
an integrator that combines source image data with predicted image data to generate residual image data for a current image area, wherein the current image area is a transform unit (TU) and a TU is a partition of a coding unit (CU);
a selectable residual transformer that performs a selected color transform on the residual image data to produce transformed residual image data;
an encoder that encodes the transformed residual image data into an encoded bitstream including an indication of the selected color transform in a TU syntax element within the encoded bitstream, wherein the TU syntax element is at a lower syntax layer in a syntax layer hierarchy than a CU syntax layer and a coding tree unit (CTU) syntax layer.
2. The system of claim 1 , wherein a first color component of the transformed residual image data is produced based on only one color component of the residual image data, and the other color components of the transformed residual image data are predicted based on the first color component of the residual image data.
3. The system of claim 1 , wherein image data in the encoded bitstream is split into individual color components, and wherein processing paths for each color component are separate from each other.
4. The system of claim 1 , wherein the encoder includes an entropy encoder.
5. The system of claim 1 , wherein the TU syntax element indicating the selected color transform specifies color transform parameters.