Fast gamut checking and inversion of spectral colors
First Claim
1. A color management method 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 method comprising:
- accessing a multi-spectral color image in the source device dependent color space generated using a multi-spectral source device;
converting the multi-spectral color image into a spectral reflectance representation in a spectral reflectance space;
converting the spectral reflectance representation into a spectrally-based Interim Connection Space (ICS) representation in a spectrally-based ICS;
determining whether a spectrally-based ICS value of the spectrally-based ICS representation is within a spectral gamut of an intended destination device, by determining whether the spectrally-based ICS value is included in a discrete spectral gamut descriptor that represents the spectral gamut of the destination device;
in response to a determination that the spectrally-based ICS value is included in the discrete spectral gamut descriptor, converting the spectrally-based ICS value into a destination-side color in a destination device dependent color space of the destination device; and
in response to a determination that the spectrally-based ICS value is not included in the discrete spectral gamut descriptor, spectrally gamut mapping the spectrally-based ICS color value onto the spectral gamut of the destination device, and converting the gamut-mapped spectrally-based ICS value into a destination-side color in the destination device dependent color space of the destination device,wherein the discrete spectral gamut descriptor represents the spectral gamut of the destination device as a collection of discrete cells of a subdivided bounding box that includes a set of sample points in the spectrally-based ICS that span the spectral gamut of the destination device, andwherein each cell has an attribute that represents an initial guess for an iterative search for a destination-side color for ICS values included in the cell, and the attribute is used to convert ICS values included in the cell into destination-side colors.
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Accused Products
Abstract
Color management using a discrete spectral gamut descriptor. A multi-spectral color image is converted to a spectrally-based ICS representation. In response to a determination that an ICS value is included in a discrete spectral gamut descriptor, the ICS value is converted into a destination-side color. Otherwise, the ICS color value is spectrally gamut mapped, and the gamut-mapped ICS value is converted into a destination-side color. The discrete spectral gamut descriptor includes a collection of discrete cells of a subdivided bounding box that includes a set of sample points in the ICS that span the spectral gamut of the destination device. Each cell has an attribute that represents an initial guess for a destination-side color for ICS values included in the cell, and the attribute is used to convert ICS values included in the cell into destination-side colors.
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Citations
88 Claims
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1. A color management method 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 method comprising:
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accessing a multi-spectral color image in the source device dependent color space generated using a multi-spectral source device; converting the multi-spectral color image into a spectral reflectance representation in a spectral reflectance space; converting the spectral reflectance representation into a spectrally-based Interim Connection Space (ICS) representation in a spectrally-based ICS; determining whether a spectrally-based ICS value of the spectrally-based ICS representation is within a spectral gamut of an intended destination device, by determining whether the spectrally-based ICS value is included in a discrete spectral gamut descriptor that represents the spectral gamut of the destination device; in response to a determination that the spectrally-based ICS value is included in the discrete spectral gamut descriptor, converting the spectrally-based ICS value into a destination-side color in a destination device dependent color space of the destination device; and in response to a determination that the spectrally-based ICS value is not included in the discrete spectral gamut descriptor, spectrally gamut mapping the spectrally-based ICS color value onto the spectral gamut of the destination device, and converting the gamut-mapped spectrally-based ICS value into a destination-side color in the destination device dependent color space of the destination device, wherein the discrete spectral gamut descriptor represents the spectral gamut of the destination device as a collection of discrete cells of a subdivided bounding box that includes a set of sample points in the spectrally-based ICS that span the spectral gamut of the destination device, and wherein each cell has an attribute that represents an initial guess for an iterative search for a destination-side color for ICS values included in the cell, and the attribute is used to convert ICS values included in the cell into destination-side colors. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
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23. A color management module stored in a memory of a computer, wherein the color management module is executed by the 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 color management module comprising:
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an image generation module constructed to perform an accessing step in which a multi-spectral color image generated in the source device dependent color space using a multi-spectral source device is accessed; a forward source device conversion module constructed to perform a converting step in which the multi-spectral color image is converted into a spectral reflectance representation in a spectral reflectance space; an ICS conversion unit constructed to perform a converting step in which the spectral reflectance representation is converted into a spectrally-based Interim Connection Space (ICS) representation in a spectrally-based ICS; a checking module constructed to perform a determining step in which it is determined whether a spectrally-based ICS value of the spectrally-based ICS representation is within a spectral gamut of an intended destination device, by determining whether the spectrally-based ICS value is included in a discrete spectral gamut descriptor that represents the spectral gamut of the destination device; an inverse destination device color conversion module constructed to perform a converting step, responsive to a determination that the spectrally-based ICS value is included in the discrete spectral gamut descriptor, in which the spectrally-based ICS value is converted into a destination-side color in a destination device dependent color space of the destination device; and a gamut mapping module constructed to perform a gamut mapping step, responsive to a determination that the spectrally-based ICS value is not included in the discrete spectral gamut descriptor, in which the spectrally-based ICS color value is spectrally gamut mapped onto the spectral gamut of the destination device, and in which the gamut-mapped spectrally-based ICS value is converted into a destination-side color in the destination device dependent color space of the destination device, wherein the discrete spectral gamut descriptor represents the spectral gamut of the destination device as a collection of discrete cells of a subdivided bounding box that includes a set of sample points in the spectrally-based ICS that span the spectral gamut of the destination device, and wherein each cell has an attribute that represents an initial guess for an iterative search for a destination-side color for ICS values included in the cell, and the attribute is used to convert ICS values included in the cell into destination-side colors. - View Dependent Claims (24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44)
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45. A color management apparatus comprising:
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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 a source-side color in a source device dependent color space into a counterpart destination-side color in a destination device dependent color space, and include computer-executable process steps to; access a multi-spectral color image in the source device dependent color space generated using a multi-spectral source device; convert the multi-spectral color image into a spectral reflectance representation in a spectral reflectance space; convert the spectral reflectance representation into a spectrally-based Interim Connection Space (ICS) representation in a spectrally-based ICS; determine whether a spectrally-based ICS value of the spectrally-based ICS representation is within a spectral gamut of an intended destination device, by determining whether the spectrally-based ICS value is included in a discrete spectral gamut descriptor that represents the spectral gamut of the destination device; in response to a determination that the spectrally-based ICS value is included in the discrete spectral gamut descriptor, convert the spectrally-based ICS value into a destination-side color in a destination device dependent color space of the destination device; and in response to a determination that the spectrally-based ICS value is not included in the discrete spectral gamut descriptor, spectrally gamut map the spectrally-based ICS color value onto the spectral gamut of the destination device, and convert the gamut-mapped spectrally-based ICS value into a destination-side color in the destination device dependent color space of the destination device, wherein the discrete spectral gamut descriptor represents the spectral gamut of the destination device as a collection of discrete cells of a subdivided bounding box that includes a set of sample points in the spectrally-based ICS that span the spectral gamut of the destination device, and wherein each cell has an attribute that represents an initial guess for an iterative search for a destination-side color for ICS values included in the cell, and the attribute is used to convert ICS values included in the cell into destination-side colors. - View Dependent Claims (46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66)
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67. A non-transitory 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:
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accessing a multi-spectral color image in the source device dependent color space generated using a multi-spectral source device; converting the multi-spectral color image into a spectral reflectance representation in a spectral reflectance space; converting the spectral reflectance representation into a spectrally-based Interim Connection Space (ICS) representation in a spectrally-based ICS; determining whether a spectrally-based ICS value of the spectrally-based ICS representation is within a spectral gamut of an intended destination device, by determining whether the spectrally-based ICS value is included in a discrete spectral gamut descriptor that represents the spectral gamut of the destination device; in response to a determination that the spectrally-based ICS value is included in the discrete spectral gamut descriptor, converting the spectrally-based ICS value into a destination-side color in a destination device dependent color space of the destination device; and in response to a determination that the spectrally-based ICS value is not included in the discrete spectral gamut descriptor, spectrally gamut mapping the spectrally-based ICS color value onto the spectral gamut of the destination device, and converting the gamut-mapped spectrally-based ICS value into a destination-side color in the destination device dependent color space of the destination device, wherein the discrete spectral gamut descriptor represents the spectral gamut of the destination device as a collection of discrete cells of a subdivided bounding box that includes a set of sample points in the spectrally-based ICS that span the spectral gamut of the destination device, and wherein each cell has an attribute that represents an initial guess for an iterative search for a destination-side color for ICS values included in the cell, and the attribute is used to convert ICS values included in the cell into destination-side colors. - View Dependent Claims (68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88)
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Specification