In a document represented by CMYK process colors, a color that a user wishes to remove is prevented from remaining without being removed by specified color removal, and even a color that the user does not wish to remove by rights is prevented from being removed.

A method for generating device-dependent color values which satisfy a colorant limit for an output device includes, for an input color defined by input values for three color channels in a first device-dependent color space, converting the input values to a hue angle , a saturation S, and value V in a second device-dependent color space. Minimum, maximum and middle ones of the input values are identified. The minimum is set to zero and the middle adjusted to maintain the input hue angle. A hue leaf relating output colorant mixture to input color can be constructed for the hue angle, and partitioned into regions. The region of the hue leaf containing the input color is identified and interpolated to identify intermediate values for the input color in a third device-dependent color space, such as CMYK. Output values in the third device-dependent color are the intermediate values or values derived therefrom.

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.

For the mapping in a non-linear color space of source colors belonging to a same constant-hue leaf, instead of using a lightness mapping function based only on a cusp lightness condition stating that a source cusp color of this leaf should be mapped into a corresponding target cusp color of this leaf, it is proposed to build such a function also on other source cusp color(s) and other target cusp color(s) having hues different from that of said leaf. Preferably, the hue interval in which these other colors are considered is representative of the curvature of the non-linear color space at the position of colors of this constant-hue leaf.

Embodiments of the present invention disclose a method, computer program product, and system for cataloging images based on a gridded color histogram analysis. The computer accesses an image gallery specified by a user, wherein the image gallery is at least one of an image gallery stored on a user computing device, an image gallery stored on a user account at a third-party image storage, or an image gallery searched on the web. The computer receives a request to search the image gallery specified by the user. The computer performs a search of the image gallery, wherein the search is using a color based histogram algorithm based on a user input. The computer transmits a cataloged and sorted image gallery to the user computing device to be displayed.

The disclosed computer-implemented method may include generating color schemes. In some embodiments, the systems described herein may generate a color scheme by plotting non-linear curves through various planes that each represent an attribute of a color, selecting points on the curves, and generating colors from the values of the points. By generating colors schemes based on non-linear curves, the systems described herein may easily and efficiently generate aesthetically pleasing color schemes with colors predictably clustered in light and dark luminosities, facilitating the creation of user interfaces that are accessible to visually impaired users. Various other methods, systems, and computer-readable media are also disclosed.

Methods, systems and computer readable media for color management are described. In some implementations, the method can include accessing one or more buildup curves associated with a combination of a substrate, one or more colorants and a colorant dispenser. The method can also include accessing a design file specifying a design and including one or more layer files each specifying a layer color. The method can further include generating, for each layer color, a corresponding colorization recipe based on the one or more buildup curves. The method can also include creating a production job instruction/metadata file having a link to the design instruction/metadata file and including parameters associated with the colorant dispensing job to be carried out using the design instruction/metadata file.

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.

An image data generating method of generating an image from a document includes acquiring, based on light reflected by the document, a first image signal corresponding to a plurality of components in a plurality of visible wavelength ranges and a component having a reflection absorption characteristic in an invisible wavelength range, converting the first image signal into a second image signal including a plurality of device-independent color space components and a black component, and generating image data based on the second image signal.

Methods, apparatuses, and systems are disclosed for simulating a tooth whitening procedure. The simulation may generally obtain a patient's two-dimensional or three-dimensional dental scan and color space convert color information from a first or native color space to a color space based on an International Commission on Illumination color space (CIELAB). The simulation may include modifying color information in the CIELAB color space then returning the modified color information to the native color space.