Adaptive reference picture generation
View Patent ↗A video encoder and corresponding method are provided for encoding an input picture or image block using a prediction from a reference-only picture, where the encoder includes a picture buffer for storing a previously coded picture, and a reference processing unit in signal communication with the picture buffer for generating the reference-only picture from a previously coded picture; and the corresponding method includes receiving a substantially uncompressed image block, filtering ( 714 ) a previously coded picture to create an adaptive reference, motion compensating the adaptive reference, subtracting the motion compensated adaptive reference from the substantially uncompressed image block, and encoding the difference between the substantially uncompressed image block and the motion compensated adaptive reference. Video decoder and corresponding method are also disclosed.
1. A method for encoding video signal data for an image block, the method comprising:
receiving a substantially uncompressed image block;
filtering a previously coded picture to create an adaptive reference;
motion compensating the adaptive reference;
determining a difference between the motion compensated adaptive reference and the substantially uncompressed image block; and
encoding the difference between the substantially uncompressed image block and the motion compensated adaptive reference.
2. A method as defined in claim 1 , further comprising:
decoding the encoded difference;
adding the decoded difference to the motion compensated adaptive reference to form a decoded picture; and
storing the decoded picture in a picture buffer.
3. A method as defined in claim 1 wherein filtering is responsive to a bitstream field for signaling which of a plurality of filters to apply for reducing uncorrelated noise.
4. A method as defined in claim 3 wherein signaling of a filter to apply comprises specifying for each picture whether its references are filtered.
5. A method as defined in claim 3 wherein signaling of a filter to apply comprises specifying whether to use the same filter for all references.
6. A method as defined in claim 3 wherein signaling of a filter to apply comprises specifying whether to reuse a reference with different filtering parameters.
7. A method as defined in claim 3 wherein a signaled filter to apply for one reference is different from a signaled filter to apply for another reference.
8. A method for decoding video signal data for a display picture, the method comprising:
receiving a reference-only picture;
receiving uncorrelated picture data;
motion compensating the reference-only picture;
reconstituting the motion compensated reference picture with the uncorrelated picture data; and
providing the reconstituted picture as a decoded output,
wherein the uncorrelated picture data is indicative of film grain content.
9. An apparatus for encoding video signal data for an image block comprising:
a filter used for filtering a previously coded picture to create an adaptive reference;
a motion compensator in signal communication with the filter for motion compensating the adaptive reference;
a comparator for determining a difference between the motion compensated adaptive reference and the image block; and
encoding the difference between the image block and the motion compensated adaptive reference.
10. An apparatus as defined in claim 9 wherein the filtering is performed responsive to a field for signaling which of a plurality of filters to apply for reducing uncorrelated noise.
11. An apparatus as defined in claim 10 wherein a signaled filter to apply for one reference is different from a signaled filter to apply for another reference.
12. An apparatus as defined in claim 10 wherein signaling of a filter to apply comprises specifying for each picture whether its references are filtered.
13. An apparatus as defined in claim 10 wherein signaling of a filter to apply comprises specifying whether to use the same filter for all references.
14. An apparatus as defined in claim 10 wherein signaling of a filter to apply comprises specifying whether to reuse a reference with different filtering parameters.
15. An apparatus for decoding video signal data for a display picture comprising:
a motion compensator for motion compensating a received reference picture; and
means for reconstituting the motion compensated reference picture with received uncorrelated picture data to provide a decoded output of the reconstituted picture,
wherein the uncorrelated picture data is indicative of film grain content.