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 method for decoding video data comprising:
decoding encoded video data to determine transformed residual sample data and to determine a selected inverse color transform for a current image area;
performing the selected inverse color transform on the transformed residual sample data to produce inverse transformed residual sample data; and
combining the inverse transformed residual sample data with motion predicted image data to generate restored image data for the current image area of an output video,
wherein the current image area is a transform unit (TU) and wherein the encoded video data identifying the selected inverse color transform is contained in a transform unit syntax.
2. The method of claim 1 , wherein a first color component of the inverse transformed residual sample data is produced based on only one color component of the transformed residual sample data, and the other color components of the inverse transformed residual sample data are predicted based on the first color component of the inverse transformed residual sample data.
3. The method of claim 1 , wherein the encoded video data is split into individual color components, and wherein processing paths for each color component are separate from each other.
4. The method of claim 1 , wherein the decoding encoded video data includes entropy decoding.
5. The method of claim 1 , wherein the encoded video data identifying the selected inverse color transform specifies two coefficients of the selected inverse color transform.
6. A system comprising:
a decoder that receives and decodes encoded video data to determine transformed residual sample data and to determine from a transform unit (TU) syntax in the encoded video data a selected inverse color transform for a current image area, wherein the current image area is a TU;
a selectable residue inverse transformer, controlled by the decoder, that performs the selected inverse color transform on the transformed residual sample data to produce inverse transformed residual sample data; and
an integrator that combines the inverse transformed residual sample data with predicted image data to generate restored image data for the current image area of an output video.
7. The system of claim 6 , wherein a first color component of the inverse transformed residual sample data is produced based on only one color component of the transformed residual sample data, and the other color components of the inverse transformed residual sample data are predicted based on the first color component of the inverse transformed residual sample data.
8. The system of claim 6 , wherein the encoded video data is split into individual color components, and wherein processing paths for each color component are separate from each other.
9. The system of claim 6 , wherein the current image area is a transform unit (TU) and wherein the encoded video data identifying the selected inverse color transform is contained in a transform unit syntax.
10. The system of claim 6 , wherein the decoder includes an entropy decoder.
11. The system of claim 6 , wherein the encoded video data identifying the selected inverse color transform specifies two coefficients of the selected inverse color transform.
12. A non-transitory computer readable medium comprising instructions that, when executed by a processor, cause:
decoding encoded video data to determine transformed residual sample data and to determine color transform parameters for a current image area;
determining a selected inverse color transform for the current image area from the color transform parameters;
performing the selected inverse color transform on the transformed residual sample data to produce inverse transformed residual sample data; and
combining the inverse transformed residual sample data with predicted image data to generate restored image data for the current image area of an output video.
13. The non-transitory computer readable medium of claim 12 , wherein a first color component of the inverse transformed residual sample data is produced based on only one color component of the transformed residual sample data, and the other color components of the inverse transformed residual sample data are predicted based on the first color component of the inverse transformed residual sample data.
14. The non-transitory computer readable medium of claim 12 , wherein the encoded video data is split into individual color components, and wherein processing paths for each color component are separate from each other.
15. The non-transitory computer readable medium of claim 12 , wherein the current image area is a transform unit (TU) and wherein the encoded video data identifying the color transform parameters is contained in a transform unit syntax.
16. The non-transitory computer readable medium of claim 12 , wherein the instructions that cause decoding encoded video data include instructions that cause entropy decoding.
17. The non-transitory computer readable medium of claim 12 , wherein the color transform parameters specify two coefficients of the selected inverse color transform.
18. The system of claim 12 , wherein the predicted image data is the result of inter prediction.
19. The system of claim 12 , wherein the predicted image data is the result of intra prediction.