Method and apparatus for encoding/decoding a high dynamic range picture into a coded bitstream

A method for coding at least one high dynamic range picture into a coded bitstream, said method comprising:

• selecting a predetermined post-processing colour correction function bp_det among a set of predetermined post-processing colour correction functions bpset, according to at least one parameter computed from said at least one high dynamic range picture,
• determining a pre-processing colour correction function b0 from said selected predetermined post-processing colour correction function bp_det,
• decomposing said high dynamic range picture into a standard dynamic range picture, using said pre-processing colour correction function b0,
• coding into said coded bitstream said standard dynamic range picture and the at least one parameter representative of the selected predetermined post-processing colour correction function bp_det.

An apparatus for coding at least one high dynamic range picture into a coded bitstream, comprising at least one processor configured for:

• selecting a first predetermined post-processing colour correction function bp_det among a first set of predetermined post-processing colour correction functions bpset, according to at least one parameter computed from said at least one high dynamic range picture,
• determining a pre-processing colour correction function b0 from said selected first predetermined post-processing colour correction function bp_det,
• decomposing said high dynamic range picture into a standard dynamic range picture, using said pre-processing colour correction function b0,
• selecting a second predetermined post-processing colour correction function bp_default among a second set of predetermined post-processing colour correction function bsetp_default which are known to a decoder, according to characteristics of the high dynamic range picture,
• determining an adjustment function fadj used to adjust said selected second predetermined colour correction function bp_default into a third post-processing colour correction function bp_dec and defined such that said third post-processing colour correction function bp_dec maps as much as possible the second selected predetermined colour correction function bP_default to the selected first predetermined post-processing colour correction function bp_det by minimizing their difference |bp_det−bp_dec|,
• coding into said coded bitstream said standard dynamic range picture and said adjustment function fadj.

An apparatus for coding at least one high dynamic range picture into a coded bitstream, comprising at least one processor configured for:

• selecting a predetermined post-processing colour correction function bp_det among a set of predetermined post-processing colour correction functions bpset, according to at least one parameter computed from said at least one high dynamic range picture,
• determining a pre-processing colour correction function b0 from said selected predetermined post-processing colour correction function bp_det,
• decomposing said high dynamic range picture into a standard dynamic range picture, using said pre-processing colour correction function b0,
• coding into said coded bitstream said standard dynamic range picture and the at least one parameter representative of the selected predetermined post-processing colour correction function bp_det.