Methods and systems for combined lossless and lossy coding

1. An encoder, the encoder comprising circuitry configured to:

receive an input video;

for a current picture:

identify a first sub-picture of the current picture to be encoded using a lossless encoding protocol;

identify a second sub-picture of the current picture to be encoded with a lossy coding protocol;

encode the current picture, wherein encoding the current picture further comprises:

encoding the first sub-picture using the lossless encoding protocol and the second sub-picture using the lossy encoding protocol;

inserting an indication that the first sub-picture is encoded according to a lossless encoding protocol in a first sub-picture header;

inserting an indication that the second sub-picture is encoded according to a lossy encoding protocol in a second sub-picture header;

associating the first sub-picture header with the first sub-picture and the second sub-picture header with the second subpicture; and

including the first and second sub-picture headers in the bitstream.

2. A method of combined lossless and lossy coding, the method comprising:

receiving, by an encoder, an input video;

for a current picture;

identifying, by the encoder, a first subpicture of the current picture to be encoded using a lossless encoding protocol;

identify a second sub-picture of the current picture to be encoded with a lossy coding protocol;

encoding, by the encoder, the current picture, wherein encoding the current picture further comprises:

encoding the first subpicture using the lossless encoding protocol and the second sub-picture using the lossy encoding protocol;

inserting an indication that the first sub-picture is encoded according to a lossless encoding protocol in a first sub-picture header;

inserting an indication that the second sub-picture is encoded according to a lossy encoding protocol in a second sub-picture header;

associating the first sub-picture header with the first sub-picture and the second sub-picture header with the second subpicture; and

including the first and second sub-picture headers in the bitstream.

3. An encoder for encoding a bitstream, the bitstream adapted to be decoded by a decoder being configured to:

receive the bitstream, the bitstream including a coded picture, the coded picture including a first coded sub-picture and a second coded sub-picture, the bitstream also including a first sub-picture header and a second sub-picture header;

detect in the first sub-picture header that the first sub-picture is coded using a lossless encoding protocol;

detect in the second sub-picture header that the second sub-picture is coded using a lossy encoding protocol,

decode the first sub-picture using a protocol for lossless decoding corresponding to the detected lossless encoding protocol; and

decode the second sub-picture using a protocol corresponding to the detected lossy encoding protocol.

4. The encoder of claim 3 wherein the first sub-picture is an independently coded sub-picture.

5. The encoder of claim 3 wherein the second sub-picture is an independently coded sub-picture.

6. The encoder of claim 3 wherein the picture includes a region coded using transform skip residual coding.

7. The encoder of claim 6 wherein the region coded using transform skip residual coding is the first sub-picture.