Methods and systems for combined lossless and lossy coding

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.

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.