Patent ID: 7483486

Claim:
A method for encoding high dynamic range video by means of video compression comprising the steps: (a) providing high dynamic range (HDR) tristimulus color data (XYZ) for each frame of the video and threshold versus intensity data for a human observer; (b) constructing a perceptually conservative luminance transformation from continuous luminance data (Y) to discrete values (L p ) using said threshold versus intensity data for the human observer, the luminance transformation (l=Ψ −1 (y)) being constructed such that a quantization error is always lower than a threshold (Δy) of perceivable luminance, wherein the luminance transformation (l=Ψ —1 (y)) is constructed using the formula dΨ(l)/dl=2*f −1 *tvi(Ψ(l)), where dΨ/dl is a derivative of a luminance function Ψ(l) and f is a variable indicating how much lower than a threshold versus intensity function (tvi( )) for a particular luminance level maximum quantization errors are; (c) by using the luminance transformation constructed in step (b), transforming the HDR tristimulus color data into perceptually linear color data of three color channels (L p , u′, v′) for obtaining visually lossless compressed frames; (d) estimating motion vector of said consecutive frames of the video and compensating differences of the tristimulus color data for performing an inter-frame encoding and an inter-frame compression; (e) transforming the compensated differences of the tristimulus color data to frequency space data; (f) quantizing said frequency space data; (g) variable-length encoding of the quantized frequency space data; and (h) storing or transmitting a stream of visual data resulting from the encoded quantized frequency space data.