Patent ID: 8411206

Claim:
A method for decoding an input signal, comprising: receiving image data signals in a digitized gamma-corrected YCbCr format encoded in an extended YCC color space; normalizing the received image data signals to recover normalized luminance and chrominance Y′C b ′C r ′ formatted data signals from the YCbCr formatted data signals; scaling and offsetting the normalized Y′C b ′C r ′ formatted data signals to offset for guard-banding; performing a conversion operation on the normalized, scaled and offset Y′C b ′C r ′ formatted data signals to obtain extended R′G′B′ formatted data signals; scaling and offsetting the extended R′G′B′ formatted data signals, the scaling and offsetting for each extended R′G′B′ component determined by an amount of negative offsetting needed so the extended R′G′B′ components will be substantially non-negative for any potential input YCbCr format value and fall within a given positive range of integer values; and performing a degamma operation on the extended R′G′B′ formatted data to obtain RGB formatted data without gamma correction; wherein the normalizing comprises recovering normalized luminance and chrominance data Y′C b ′C r ′ determined by: Y′=b 11 ′×Y+b 12 ′ C b ′=b 21 ′×C b +b 22 ′ C r ′=b 31 ′×C R +b 32 ′ with coefficients determined to substantially invert the digitizing process performed to transform gamma-corrected RGB data into YCbCr format.