Patent ID: 8594188

Claim:
A method for coding pictures of a wide dynamic range, the method being performed with a video coding system comprising at least an encoder, the method comprising: determining a set of representational quantization parameter (QP) codes having at least 32 values, wherein the set of representational quantization parameters codes is within a first set of levels; extending the first set of levels of said representational quantization parameter codes into a wider second set of levels using a non-linear mapping function, wherein the wider second set of levels correspond to a set of determined quantization parameter (QPd) values, and wherein extending the first set of levels of the representational quantization parameter codes comprises a mapping of respective representational quantization parameter codes to corresponding determined quantization parameter values; for each macroblock of a picture, selecting a representational quantization parameter code from the set of representational quantization parameter codes; for each macroblock of the picture, using the mapping to select a determined quantization parameter value for the selected representational quantization parameter code; and quantizing transform coefficients of the macroblock, with the encoder, using the selected determined quantization parameter value.