Piecewise color transformation by gamut partitioning

A color correction system for identifying a target color from a printer gamut in a subtractive color-space that corresponds to a source color in a source color-space, said system comprising:

• a gamut transformation module adapted to convert said printer gamut into an equivalent gamut in said source color-space, said equivalent gamut having a plurality of non-overlapping constituent volumes, said constituent volumes sharing a common boundary point;
• a volume finder having access to said plurality of constituent volumes and to said source color, said volume finder adapted to identify a source-bearing volume from said plurality of constituent volumes;
• a volume mapper for matching a target-bearing volume in said printer gamut in said subtractive color-space with said source-bearing volume in said equivalent gamut in said source color space;
• and
• a coordinate mapper, which comprises barycentric mapping means for determining barycentric coordinates of said source color relative to said source-bearing volume for determining a target color in said target-bearing volume that corresponds to said source color in said source-bearing volume.

A color correction system for identifying a target color from a printer gamut in a subtractive color-space that corresponds to a source color in a source color-space, said system comprising:

• a gamut transformation module adapted to convert said printer gamut into an equivalent gamut in said source color-space, said equivalent gamut having a plurality of non-overlapping constituent volumes, said constituent volumes sharing a common boundary point;
• a volume finder having access to said plurality of constituent volumes and to said source color, said volume finder adapted to identify a source-bearing volume from said plurality of constituent volumes;
• a volume mapper for matching a target-bearing volume in said printer gamut in said subtractive color-space with said source-bearing volume in said equivalent gamut in said source color space;
• and
• a coordinate mapper for determining a target color in said target-bearing volume that corresponds to said source color in said source-bearing volume, which comprises a gamut compressor for generating a compressed printer-gamut, said gamut comprising:
• print selection means defining a ray extending between said common boundary point and said target color;
• and
• compression means for translating said target color toward said common boundary point along said ray.

A method for identifying a target color from a printer gamut in a subtractive color-space that corresponds to a source color in a source color-space, said method comprising the steps of:

• transforming said printer gamut into an equivalent gamut in said source color-space;
• said equivalent gamut having a plurality of non-overlapping constituent volumes, said constituent volumes sharing a common boundary point;
• identifying a source-bearing volume from said plurality of constituent volumes;
• matching a target-bearing volume in said printer gamut in said subtractive color-space with said source-bearing volume in said equivalent gamut in said source color-space;
• and
• determining a target color in said target-bearing volume that corresponds to said source color in said source-bearing volume.

A method for identifying a target color from a printer gamut in a subtractive color-space that corresponds to a source color in a source color-space, said method comprising the steps of:

• transforming said printer gamut into an equivalent gamut in said source color-space;
• said equivalent gamut having a plurality of non-overlapping constituent volumes, said constituent volumes sharing a common boundary point;
• identifying a source-bearing volume from said plurality of constituent volumes;
• matching a target-bearing volume in said printer gamut in said subtractive color-space with said source-bearing volume in said equivalent gamut in said source color-space;
• and
• determining a target color in said target-bearing volume that corresponds to said source color in said source-bearing volume by determining barycentric coordinates of said source color relative to said source-bearing volume.

A method for identifying a target color from a printer gamut in a subtractive color-space that corresponds to a source color in a source color-space, said method comprising the steps of;

• transforming said printer gamut into an equivalent gamut in said source color-space;
• said equivalent gamut having a plurality of non-overlapping constituent volumes, said constituent volumes sharing a common boundary point;
• identifying a source-bearing volume from said plurality of constituent volumes;
• matching a target-bearing volume in said printer gamut in said subtractive color-space with said source-bearing volume in said equivalent gamut in said source color-space;
• and
• determining a target color in said target-bearing volume that corresponds to said source color in said source-bearing volume by defining a ray extending between said common boundary point and said target color, and translating said target color toward said common boundary point along said ray.