Patent ID: 7864366

Claim:
A method of transforming color image data from an N-dimensional input color space to an M-dimensional output color space, the method comprising: providing a lookup table comprising table entries with M output color space values for performing an initial interpolation that takes the form of a weighted sum of the lookup table entries; for each N-dimensional pixel of the color image data having N input color space pixel values: performing an initial interpolation of the input color space pixel values using the lookup table entries to compute M initial output color space pixel values; converting the initial output color space pixel values into luminance-chrominance color space pixel values; using a processor, computing an adjustment value Î» according to the luminance-chrominance color space pixel values at least partially according to chrominance values of the luminance-chrominance color space pixel values, wherein computing the adjustment value Î» comprises: if the chrominance values of the luminance-chrominance color space pixel values are all zero, setting a value Ïƒ to 1, if the chrominance values of the luminance-chrominance color space pixel values are not all zero: computing a saturation value for the luminance-chrominance color space pixel values, and computing the value Ïƒ by interpolating the luminance-chrominance color space pixel values according to saturation values for the luminance-chrominance color space pixel values and for boundary nodes defining an (N+1) sided body corresponding to the current pixel, and computing the adjustment value Î» according to the value Ïƒ; and computing final output color space pixel values according to the initial output color space pixel values and the adjustment value Î».