Image-based source gamut adjustment for compression-type gamut mapping algorithm

A color management module which converts a source-side color in a source device dependent color space into a counterpart destination-side color in a destination device dependent color space, said color management module comprising:

• an obtaining module constructed to obtain a device independent source device gamut boundary for a source device and a device independent destination device gamut boundary for a destination device;
• an image obtaining module constructed to obtain a source color image in the source device dependent color space;
• a transforming module constructed to transform the source color image into a device independent image in a device independent color space;
• a gamut boundary generating module constructed to generate an image gamut boundary for the device independent image, based on color content of the device independent image;
• a modifying module constructed to modify the source device gamut boundary by shrinking the source device gamut boundary in a hue symmetric manner, such that hues of colors do not change, until it touches the image gamut boundary;
• and
• a mapping module constructed to map colors of the device independent image onto a gamut of the destination device by invoking a compression-type gamut mapping algorithm that uses the modified source device gamut boundary and the destination device dependent gamut boundary to perform gamut mapping,
• wherein the gamut mapped colors are converted into destination-side colors in the destination device dependent color space.

A color management apparatus comprising:

• a computer-readable memory constructed to store computer-executable process steps;
• and
• a processor constructed to execute the computer-executable process steps stored in the memory;
• wherein the process steps stored in the memory cause the processor to convert source-side colors in a source device dependent color space into counterpart destination-side colors in a destination device dependent color space, and include computer-executable process steps to:
• obtain a device independent source device gamut boundary for a source device and a device independent destination device gamut boundary for a destination device;
• obtain a source color image in the source device dependent color space;
• transform the source color image into a device independent image in a device independent color space;
• generate an image gamut boundary for the device independent image, based on color content of the device independent image;
• modify the source device gamut boundary by shrinking the source device gamut boundary in a hue symmetric manner, such that hues of colors do not change, until it touches the image gamut boundary;
• and
• map colors of the device independent image onto a gamut of the destination device by invoking a compression-type gamut mapping algorithm that uses the modified source device gamut boundary and the destination device dependent gamut boundary to perform gamut mapping,
• wherein the gamut mapped colors are converted into destination-side colors in the destination device dependent color space.

A computer-readable memory medium on which is stored computer-executable process steps for causing a computer to convert a source-side color in a source device dependent color space into a counterpart destination-side color in a destination device dependent color space, said process steps comprising:

• obtaining a device independent source device gamut boundary for a source device and a device independent destination device gamut boundary for a destination device;
• obtaining a source color image in the source device dependent color space;
• transforming the source color image into a device independent image in a device independent color space;
• generating an image gamut boundary for the device independent image, based on the color content of the device independent image;
• modifying the source device gamut boundary by shrinking the source device gamut boundary in a hue symmetric manner, such that hues of colors do not change, until it touches the image gamut boundary;
• and
• mapping colors of the device independent image onto a gamut of the destination device by invoking a compression-type gamut mapping algorithm that uses the modified source device gamut boundary and the destination device gamut boundary to perform gamut mapping,
• wherein the gamut mapped colors are converted into destination-side colors in the destination device dependent color space.