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 obtaining a preserved key color (prsv_color.sub.K0) and a hue alignment angle (.sub.K0) of the key color (color.sub.K0) for each key color (color.sub.K0) of at least 3 key colors to define a preserved gamut and a rotated gamut; and performing a hue mapping of a current color (color) from the first color gamut towards the second color gamut wherein in case the current color (color) is in a preserved gamut defined by the preserved key color (prsv_color.sub.K0), the hue mapped current color is unchanged, and in case the current color is out of the preserved gamut, the hue mapped current color is calculated from the hue alignment angle (.sub.K0) of two adjacent key colors of the current color (rotated gamut) and from the preserved area.

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.

A color of an image that is printed based on a second color value obtained by converting a color value of a specific color falling outside a color gamut without using a first conversion table is closer to the specific color falling outside the color gamut than a color of an image that is printed based on a first color value obtained by converting the color value of the specific color falling outside the color gamut by using the first conversion table.

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.

In an example, an image processing system may include an identification engine, a map engine, and a control engine. In that example, the identification engine may identify a color mapping resource in response to a classification identifier corresponding to image data, the map engine may map the image data with the color mapping resource having color space clause corresponding to the classification identifier, and the control engine may generate control data for operating a print apparatus to print based on the color mapping resource.

A print control apparatus that realizes printed matter that appears suitably in a case of observation by reflected light and in a case of observation by transmitted light is disclosed. The print control apparatus, based on data of a source image, generates first print data to be used for printing to a first surface of a recording medium. The print control apparatus also, based on data of the source image, generates second print data that is used for printing to a second surface that is different to the first surface and that represents a higher luminance range, in a luminance range that the data of the source image represents, than a luminance range that the first print data represents.

Printers can be desirably color matched irrespective of whether or not a specified color is a color in the gamut range. A client device 100 determines by a gamut range evaluator 232 whether or not a specified color is a color in the gamut range, which is the range of colors a second printer 50 can reproduce; causes a color chart data generator 235 to generate image data for producing a color chart referenced to the specified color when the specified color is a color in the gamut range; and causes the generator to select a color on the gamut surface based on the specified color when the specified color is a color outside the gamut range, and generate the image data to create the color chart referenced to the selected color.

A method of performing gamut mapping on an input image for an image output device includes receiving the input image to analyze a color distribution of the input image; determining a protect range corresponding to a first percentage of color codes of the input image and a compression range corresponding to a second percentage of the color codes of the input image based on the color distribution of the input image; and moving at least one of the color codes of the input image outside the protect range of the color codes to the compression range by a compression algorithm to perform gamut mapping on the input image.

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.

Method of color measuring a color of a rendered copy of a digital image, by a color-measuring-device (3000) for color measuring in a plurality of spectral ranges (r.sub.1 . . . r.sub.Q); wherein said method comprises the step: measuring said color is measured in a sub-set (s.sub.1 . . . s.sub.M; .sub.3305) of said plurality of spectral ranges (r.sub.1 . . . r.sub.Q); and wherein said sub-set (s.sub.1 . . . s.sub.M) is determined by: selecting a color of a gamut boundary of said digital image (1200); and determining of said color for said plurality of spectral ranges (r.sub.1 . . . r.sub.Q) corresponding spectral reflectance factors (v.sub.1 . . . v.sub.Q); and adding a spectral range (r.sub.i), having a minimum and maximum spectral reflectance factor, to said sub-set (s.sub.1 . . . s.sub.M) wherein its corresponding spectral reflectance value (v.sub.i) is larger than 10% of said maximum spectral reflectance factor minus said minimum spectral reflectance factor.