An image processing device includes: a first color conversion processor configured to perform first color conversion processing on image data; a second color conversion processor configured to perform second color conversion processing on the image data; a coefficient calculator configured to calculate a coefficient indicating a blend ratio between an output of the first color conversion processor and an output of the second color conversion processor; and a blend processor configured to blend the output of the first color conversion processor and the output of the second color conversion processor based on the ratio indicated by the coefficient, wherein the coefficient calculator calculates a position on an xy chromaticity diagram of a color indicated by each pixel in image data processed by the first color conversion processor to determine the coefficient based on a distance from the calculated position to a boundary of a color gamut.

Methods and systems for gamut mapping are disclosed. Pixels of an image or points of a look-up-table can be gamut mapped in a multi-step iterative process, by generating a coarse gamut hull and calculating a value of a distance metric for out-of-gamut pixels or LUT points, and subsequently generating a fine gamut hull in the neighborhood of the coarse gamut hull points closest to the out-of-gamut pixel or LUT points under consideration. The out-of-gamut pixel or LUT point is gamut mapped based on the smallest distance metric value calculated.

A method of gamut mapping and color gamut mapping apparatus comprises: acquiring the Lab value of the color point in the original color gamut; and determining the color point in the original color gamut relative to the coordinate location in a hue plane based on the Lab value; and determining the mapping target gamut of the color point based on the coordinate location; If a color point is located outside the mapping target area, it determining the first intersection point of the line connecting the color point and the maximum brightness and the borderline of the mapping target color gamut and the second intersection point of the color point relative to the borderline of the mapping target gamut, and finally according to the preset adjustment parameter, the mapping point being determined on the borderline of the mapping target color gamut relative to the color point.

A method includes receiving information specifying a color gamut. The color gamut corresponds to a range of colors producible by an output device. The method further includes receiving a first indication of a first color associated with a first point in a geometrical representation of the color gamut in a three-dimensional (3D) color space. The method further includes generating, based on the first color, a second indication of a second color that is included in the color gamut. The second color is associated with a second point in the 3D color space. The second point is identified based on a particular value of data associated with a plurality of distances between the first point and a subset of points of the geometrical representation. The subset of points includes more than one and fewer than all points of the geometrical representation.

A color gamut mapping method and a color gamut mapping device is provided, the method includes: determining a mapping target color gamut; obtaining a Lab value of a color point in the original color gamut, and determining a coordinate position of the color point in a corresponding tone plane of the original color gamut; judging the color point position; determining an intersection of a horizontal line the color point located and a boundary of the original color gamut, and a boundary of the mapping target color gamut; and determining a mapping point of the color point on the boundary of the map target color gamut by a ratio of an area of a pattern formed by the intersection, and an intersection of the original color gamut and a coordinate axis, and a difference between the area of the original color gamut and the area of the mapping target color gamut.

The present principles relate to a method and device for gamut mapping from a first color gamut towards a second color gamut. The method comprises, in a plane of constant hue, obtaining a target lightness for a color on the boundary of first gamut with maximum chroma, called first cusp color; and lightness mapping of the color from the first color gamut towards the second color gamut wherein the lightness mapped color is calculated from a parabolic function applied to the color, the parabolic function mapping the first cusp color to a color having the target lightness. According to a particular characteristic, a preserved chroma is also obtained; and in case the chroma of the color is lower than or equal to the preserved chroma, the lightness mapped color is the color, and in case the chroma of the color is higher than the preserved chroma, the lightness mapped color is calculated from the parabolic function applied to the color.

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.

An embodiment may involve obtaining a three-dimensional color model containing hue, lightness, and chroma dimensions. The color model may represent each of at least one thousand distinct colors as unique points within the hue, lightness, and chroma dimensions. The embodiment may involve displaying, in accordance with the color model, a rotatable three-dimensional representation of the unique points. The embodiment may further involve receiving a selection of a first point of the unique points and a selection of a second point of the unique points. The embodiment may involve, in response to receiving the selection of the first point and the selection of the second point, displaying, in accordance with the color model, a rotatable three-dimensional representation of the first point, the second point, a line connecting the first point and the second point, and a subset of the unique points that are within a particular radius of the line.

A method includes receiving information specifying a color gamut. The color gamut corresponds to a range of colors producible by an output device. The method further includes receiving a first indication of a first color associated with a first point in a geometrical representation of the color gamut in a three-dimensional (3D) color space. The method further includes generating, based on the first color, a second indication of a second color that is included in the color gamut. The second color is associated with a second point in the 3D color space. The second point is identified based on a particular value of data associated with a plurality of distances between the first point and a subset of points of the geometrical representation. The subset of points includes more than one and fewer than all points of the geometrical representation.

A perceptual hue preserved (PHP) color gamut transferring (CGT) method carried out in CIE-1931 color space includes obtaining a target gamut based on a rendering device of a content. Multiple color-moving constraints (CMC) are retrieved from a dataset. Perceptually consistent hue loci (PCHL) of out-of-gamut (OOG) colors of the content are estimated according to the CMC and a protection zone boundary. Each of the OOG colors are moved along its PCHL to a final point inside the target gamut based on a CGT plan data. The CGT plan data includes target and source boundary information formed using the CMC and the protection zone boundary.