Methods and systems of video coding using reference regions

1. A decoder, the decoder comprising circuitry configured to:

receive a bitstream including a sequence parameter set and a first coded picture;

detect in the sequence parameter set associated with the first coded picture, that a coded sub-picture is present in the first coded picture and a location of the coded sub-picture in the first coded picture;

extract from the first coded picture, and decode, the coded sub-picture to form a reference picture;

determine a predictor from the reference picture using a scaling constant, the scaling constant being determined from information in the bitstream; and

use the predictor to decode a subsequent picture in the bitstream.

2. A decoder, the decoder comprising circuitry configured to:

receive a bitstream including a sequence parameter set and a first coded picture;

detect in the sequence parameter set associated with the first coded picture, the location of a first coded sub-picture in the first coded picture and the location of a second coded sub-picture in the first coded picture;

extract and decode the first coded sub-picture to form a first reference picture;

extract and decode the second coded sub-picture to form a second reference picture;

determine a first predictor in the first reference picture using a first scaling constant determined from information in the bitstream; and

determine a second predictor in the second reference picture using a second scaling constant determined from information in the bitstream.

3. A method of video decoding, the method comprising:

receiving, by a decoder, a bitstream including a sequence parameter set and a first coded picture;

detecting, by the decoder, in the sequence parameter set associated with the first coded picture, that a coded sub-picture region is present in the first coded picture and a location of the coded sub-picture region in the first coded picture;

extracting, by the decoder, the coded sub-picture region from the first coded picture to form a decoded independent picture that is used as a reference picture;

determining, by the decoder, a predictor from the reference picture using a scaling constant, the scaling constant being determined from information in the bitstream; and

using, by the decoder, the predictor to decode a subsequent picture in the bitstream.

4. The decoder of claim 1 , wherein the information in the bitstream used to obtain the scaling constant includes an index.

5. The decoder of claim 1 , wherein the predictor is formed using an interpolation filter.

6. The decoder of claim 1 , wherein the subsequent picture is a subsequent independent sub-picture.

7. The decoder of claim 4 , wherein the predictor is determined using a motion vector candidate list.

8. The decoder of claim 2 , wherein the first predictor is used to decode a first subsequent picture.

9. The decoder of claim 8 , wherein the second predictor is used to decode a second subsequent picture.

10. The decoder of claim 9 , wherein the first and second subsequent pictures are sub-pictures extracted from the same picture.

11. A decoder, the decoder comprising circuitry configured to:

receive a bitstream including a sequence parameter set and a first coded picture;

detect in the sequence parameter set associated with the first coded picture, that a coded sub-picture is present in the first coded picture and a location of the coded sub-picture in the first coded picture;

extract from the first coded picture, and decode, the coded sub-picture to form a reference picture;

determine a predictor in the reference picture using a scaling constant obtained from information in the bitstream, the information including an index; and

use the predictor to decode a subsequent picture.

12. The method of claim 3 , wherein the information in the bitstream used to obtain the scaling constant includes an index.

13. The method of claim 3 , wherein the predictor is formed using an interpolation filter.

14. The method of claim 3 , wherein the subsequent picture is a subsequent independent sub-picture.

15. The method of claim 12 , wherein the predictor is determined using a motion vector candidate list.

16. A method of video decoding, the method comprising:

receiving, using a decoder, a bitstream including a sequence parameter set and a first coded picture;

detecting, by the decoder, in the sequence parameter set associated with the first coded picture, the location of a first coded sub-picture in the first coded picture and the location of a second coded sub-picture in the first coded picture;

extracting and decoding, by the decoder, the first coded sub-picture to form a first reference picture;

extracting and decoding, by the decoder, the second coded sub-picture to form a second reference picture;

determining, by the decoder, a first predictor in the first reference picture using a first scaling constant determined from information in the bitstream; and

determining, by the decoder, a second predictor in the second reference picture using a second scaling constant determined from information in the bitstream.

17. The method of claim 16 , wherein the first predictor is used to decode a first subsequent picture.

18. The method of claim 17 , wherein the second predictor is used to decode a second subsequent picture.

19. The method of claim 18 , wherein the first and second subsequent pictures are sub-pictures extracted from the same picture.

20. A method of video decoding, the method comprising:

receiving, by a decoder, a bitstream including a sequence parameter set and a first coded picture;

detecting, by the decoder, in the sequence parameter set associated with the first coded picture, that a coded sub-picture region is present in the first coded picture and a location of the coded sub-picture region in the first coded picture;

extracting, by the decoder, the coded sub-picture region from the first coded picture to form a decoded independent sub-picture that is used as a reference picture;

determining, by the decoder, a predictor in the decoded independent sub-picture using a scaling constant obtained from information in the bitstream, the information including an index; and

using, by the decoder, the predictor to decode a subsequent picture.