A color gamut cross-section acquiring method for acquiring a cross-section of a color gamut of an image forming apparatus taken on a specific plane includes: acquiring color gamut boundary line segments; acquiring intersection points between the color gamut boundary line segments and the specific plane; acquiring a shortest possible route passing through each of the intersection points exactly once; acquiring each of line segments making up the route as a provisional cross-section boundary line segment; acquiring a set of verification line segments by connecting intersection points between the color gamut boundary line segments and a plane intersecting with the provisional cross-section boundary line segment at a point other than the endpoints of the provisional cross-section boundary line segment; and acquiring the provisional cross-section boundary line segment as a cross-section boundary line segment if the provisional cross-section boundary line segment intersects with the set of verification line segments.

Techniques for interactively determining/visualizing the color content of a source image and how the corresponding image data is mapped to device colors are described herein. For example, the color content of a digital image can be converted between different color spaces to identify gamut limitations of an output device (e.g., a printing assembly), discover color(s) that cannot be accurately reproduced, etc. Color space conversions enable the transformation of the color content of the digital image from device-specific colorants to a device-independent representation (and vice versa). In some embodiments, these transformations are facilitated using lookup tables that are implemented in graphical processing unit-resident memory.

A gamut mapping method. The method includes: inputting an original display image; transforming the original display image to obtain a frequency-domain image in a frequency domain; determining a first portion and a second portion of the frequency-domain image in the frequency domain; respectively transforming the first portion and the second portion of the frequency-domain image to obtain a first portion and a second portion of a transformed image in the spatial domain; respectively utilizing different gamut mapping principles to the first portion and the second portion to perform gamut mapping between the first portion and the second portion of the transformed image and the target device; synthesizing the first portion and the second portion to obtain a final display image. In the present invention, different frequency portions of the image perform gamut mapping independently, and the mapping result is synthesized to obtain a final image.

One or more apparatus and method for compressing xvYCC or sRGB color to a narrower color gamut. Embodiments may be utilized in processing images/video image sequences provided in a wide gamut color space for display in standard RGB color space. In further embodiments, an sRGB or xvYCC compliant input is compressed to a gamut narrower than sRGB. Embodiments where a narrow output color gamut lacks a fully-defined 3D color space, semi-fixed-hue gamut compression may be performed by adjusting parameters provided to a fixed-hue compression module capable of mapping 3D color space representations between well-defined gamuts.

A printing system is described. The printing system includes a printer having a control unit to perform color mapping from an input color space defined in a printer input profile to a printer color space defined in a printer output profile and a printing condition matching module to automatically determine a printer input profile based on a selection of one of a plurality of printing conditions, wherein a printer input profile corresponds to each of the plurality of printing conditions.

A method of defining color separation for printing an image via NPacs, the method comprising: selecting a plurality of NPacs corresponding to a plurality of points within an RGB cube to provide a tessellation in RGB space translated to a valid tessellation in an NPac-related space; and defining color separation from the selected NPacs.

This is a method for obtaining a cross-section of a color gamut of an image forming apparatus by slicing the color gamut along a plane. This method includes the steps of obtaining gamut boundary line segments, obtaining cross-section boundary line segments, and obtaining endpoints. The gamut boundary line-segment obtaining step is to obtain gamut boundary line segments serving as baseline segments of a boundary of the color gamut. The cross-section boundary line-segment obtaining step is to obtain cross-section boundary line segments serving as baseline segments of a boundary of the cross-section. The endpoints obtained in the endpoint obtaining step are points of intersection of the gamut boundary line segments and the plane. The cross-section boundary line segments obtained in the cross-section boundary line-segment obtaining step are line segments making up a route that is the shortest route passing through all the endpoints only once.

A gamut mapping method. The method includes: inputting an original display image; transforming the original display image to obtain a frequency-domain image in a frequency domain; determining a first portion and a second portion of the frequency-domain image in the frequency domain; respectively transforming the first portion and the second portion of the frequency-domain image to obtain a first portion and a second portion of a transformed image in the spatial domain; respectively utilizing different gamut mapping principles to the first portion and the second portion to perform gamut mapping between the first portion and the second portion of the transformed image and the target device; synthesizing the first portion and the second portion to obtain a final display image. In the present invention, different frequency portions of the image perform gamut mapping independently, and the mapping result is synthesized to obtain a final image.

A printing system is described. The printing system includes a printer having a control unit to perform color mapping from an input color space defined in a printer input profile to a printer color space defined in a printer output profile and a printing condition matching module to automatically determine a printer input profile based on a selection of one of a plurality of printing conditions, wherein a printer input profile corresponds to each of the plurality of printing conditions.

A method for determining whether an image or color is out of gamut for a device. The method may include receiving a source image or color in a first color space, the first color space corresponding to a first device, converting the image or color to a second color space, the second color space corresponding to a second device, converting the image or color back to the first color space to produce a converted image, comparing the source image or color and the converted image or color, and calculating an out-of-gamut score for the converted image or color. In some embodiments, an out-of-gamut score may be compared to a threshold value, and in some embodiments, the method may include notifying a user if the out-of-gamut score exceeds the threshold.