Source color volume information messaging
Methods are described to communicate source color volume information in a coded bitstream using SEI messaging. Such data include at least the minimum, maximum, and average luminance values in the source data plus optional data that may include the color volume x and y chromaticity coordinates for the input color primaries (e.g., red, green, and blue) of the source data, and the color x and y chromaticity coordinates for the color primaries corresponding to the minimum, average, and maximum luminance values in the source data. Messaging data signaling an active region in each picture may also be included.
1. A method to extract source color volume information of an input bitstream from associated metadata, the method executed on a processor, the method comprising:
receiving, by the processor, an input video bitstream with color volume metadata comprising source color volume information for the input video bitstream;
if a metadata flag indicates source color primaries metadata is present, then
for one or more color primaries, extracting from the metadata x and y chromaticity coordinates defining for each of the one or more color primaries a 2D color gamut of the input video bitstream; and
extracting from the metadata luminance value parameters comprising an average luminance value, wherein the average luminance value is for one or more decoded pictures or an active region of one or more decoded pictures in the input video bitstream.
2. The method of claim 1 , further comprising, generating an output video signal based on the input video bitstream and the metadata for the source color volume information.
3. The method of claim 1 , wherein the x and y chromaticity coordinates are specified in increments of 0.00002, according to the CIE 1931 definition of x and y as specified in ISO 11664-1.
4. A method to generate an encoded bitstream, the method comprising:
receiving a sequence of video pictures;
encoding one or more of the video pictures to generate compressed video pictures;
generating a metadata message indicating color volume metadata that comprises source color volume information for the compressed video pictures; and
generating an output video bitstream comprising the compressed video pictures and the metadata message, wherein the color volume metadata indicated in the metadata message comprises:
normalized x and y chromaticity coordinates of one or more color primary components in the encoded bitstream; and
luminance value parameters comprising an average luminance value, wherein the average luminance value is for an active region of one or more coded pictures in the encoded bitstream.
5. The method of claim 4 , wherein the normalized x and y chromaticity coordinates are specified in increments of 0.00002, according to the CIE 1931 definition of x and y as specified in ISO 11664-1.
6. The method of claim 4 , wherein the metadata message comprises a supplemental enhancement information, SEI, message.
7. The method of claim 4 , wherein the metadata message further comprises information related to the active region.