Patent ID: 8542402

Claim:
A method of determining a spectral gamut of a device during an off-line phase by constructing plural subdivisions of a spanning set of samples which span the spectral gamut, the method comprising: establishing a first crude spanning set of samples by specifying one or more corresponding device values in a device color space; refining the first crude spanning set by processing a plurality of new samples in a predetermined order, wherein the processing includes, for each new sample, determining if the new sample does or does not differ in an objective function value by more than a predetermined threshold from all samples in the first crude spanning set, and modifying the first crude spanning set by adding the new sample to the first crude spanning set if the new sample differs in the objective function value by more than the predetermined threshold from all samples in the first crude spanning set; designating the resulting first crude spanning set as the spanning set of samples; obtaining a spectral reflectance array for each sample in the spanning set; generating a colorimetric value for each sample in the spanning set by transforming the spectral reflectance array corresponding to the sample under a reference illuminant, wherein the colorimetric value includes a lightness in a lightness dimension, a chroma in a chroma dimension and a hue in a hue dimension; and subdividing the spanning set of samples into subdivisions based on the lightness, the chroma and the hue of the samples such that the number of samples in each subdivision is limited by a predetermined number, whereby in an on-line phase of spectral gamut mapping, subdivisions are identified that contain samples that are candidates for an acceptable match to an input color value which is given in the on-line phase.