There is provided a color gamut mapping device capable of fine adjustment configured to map a color signal to a predetermined color gamut by changing the saturation, hue, and luminance of the corresponding color signal, the color gamut mapping device including a hue angle calculation unit configured to calculate a hue angle using saturation components (Cb, Cr) of a YCbCr-type color signal (Y, Cb, Cr); a parameter generation unit configured to generate at least one of a saturation parameter, a luminance parameter, and a hue parameter using the hue angle; and a color signal changing unit configured to change the YCbCr-type color signal (Y, Cb, Cr) to be mapped to a predetermined color gamut using the parameter, wherein the color signal changing unit includes a saturation changing unit configured to calculate a saturation boundary value determined as a boundary of a predetermined rectangle on a Cb-Cr coordinate plane.

An electronic device comprises a camera; a memory configured to store a plurality of tone mapping information sets, each of the tone mapping information sets comprising image information of an image frame and tone mapping information of the image frame; and a processor, wherein the processor is configured to: select a tone mapping information set based on user input; acquire a first image frame captured through the camera; obtain a first feature of the first image frame by analyzing the first image frame; identify a second feature of second image frame corresponding to the selected tone mapping information set, based on image information of the second image frame; compare the first feature and the second feature; based on the comparison result, apply tone mapping to the first image frame using tone mapping information of the second image frame; and store image data of the first image frame, in the memory.

A method for building a security image for a security structure of a security document from multiplexing color images, including selecting a marking method capable of producing sets of colors on the security document comprising different colors that can be displayed according to illumination/observation modes of the security structure, establishing a plurality of color sets that can be displayed by the security structure in a plurality of the different illumination/observation modes, distributing the color sets in a plurality of groups of color sets, establishing combinations of groups of color sets having at least one color set in common across the number of different illumination/observation modes, selecting a combination of a group of color sets based on the number of desired illumination/observation modes and the number of colors per color image, and determining the color images to multiplex by means of the combination of the group of color sets selected.

Encoding can involve correcting chroma components representing the chroma of an input image according to a first component representing a mapping of the luminance component of said input image used for reducing or increasing the dynamic range of said luminance component, and a reconstructed component representing an inverse mapping of said first component. At least one correction factor according to said at least one scaled chroma components can also be obtained and transmitted. Decoding can involve scaled chroma components being obtained by multiplying chroma components of an image by at least one corrected chroma correction function depending on said at least one correction factor. Components of a reconstructed image can then be derived as a function of said scaled chroma components and a corrected matrix that depends on an inverse of a theoretical color space matrix conversion and said at least one correction factor.

Certain examples described herein relate to mapping between an input color space and an output color space. In some cases, data representing a set of candidate output color values in the output color space is obtained for a transition region between two input color values in the input color space. A sub-region of the transition region is defined, the sub-region being associated with a target colorimetry and a target value of a metric. An output color value is selected from the set of candidate output color values. The output value has an associated value of the metric and an associated colorimetry. The selecting is based on the associated colorimetry and the target colorimetry, and the value of the metric and the target value of the metric. In some cases, mapping data is generated by assigning the selected output color value to the sub-region.

A computer system for dynamic generation of custom color selections receives from a user an indication of a target color. The computer system also identifies a location of the target color within a mathematically-defined color space. The computer system identifies a location of a second color within the mathematically-defined color space. Additionally, the computer system generates a first golden triangle within the mathematically-defined color space. The location of the target color comprises a first vertex of the first golden triangle. The location of the second color comprises a second vertex of the first golden triangle. A location of a third color comprises a third vertex of the first golden triangle. The computer system then displays on a user interface an indication of the target color, the second color, and the third color.

An image processing method includes the steps of acquiring a training image and a correct image, inputting the training image into a multilayer neural network to generate an output image, performing a gamma correction for each of the correct image and the output image and calculating an error between the correct image after the gamma correction and the output image after the gamma correction, and updating a network parameter of the neural network using the error.

A data processing method, a system and a user interface are disclosed, for dosing ink in a digital printer with at least 6 ink channels. A forward transformation model is obtained or computed for defining a relationship between coordinates of device-dependent ink values across the ink channels and coordinates of device-independent colorimetric values in a color space. An inverse model of the forward transformation model is computed, wherein the inverse model comprises an adjustable constraint on each ink channel. One or more constraints are applied to each ink channel with predetermined and/or user-defined value(s). A target colorimetric value is input to the inverse model. An ink value is computed for each ink channel with the inverse model, wherein each computed ink value corresponds to ink dosage in its respective ink channel and the computed ink values collectively correspond substantially to the target colorimetric value.

A method is disclosed wherein data representative of a plurality of colors defined in a color space is received, the plurality of colors providing a color palette taken to be related to each other by predefined color harmony rules based on their relative positions in the color space. An irreproducible color of the color palette outside a rendering system's reproducible color gamut is determined, the reproducible color gamut having been received for a rendering system on which image data comprising colors of the color palette is to be reproduced. A suggested color for a replacement color palette also complying with the predefined color harmony rules is determined based on the reproducible color gamut to bring the color palette towards being within the rendering system's reproducible color gamut.

The present principles relates to a method and device for reconstructing an High-Dynamic-Range image represented by one reconstructed High-Dynamic-Range luma component () and two reconstructed High-Dynamic-Range chroma components (.Math., (I)) from a Standard-Dynamic-Range image represented by a Standard-Dynamic-Range luma component (y, y.sub.1) and two Standard-Dynamic-Range chroma components (u, v). The method is characterized in that the method comprises: inverse-mapping (22) said Standard-Dynamic-Range luma component (y, y.sub.1) to obtain said reconstructed High-Dynamic-Range luma component (); and correcting (33) said two Standard-Dynamic-Range chroma components (u, v) to obtain said two reconstructed High-Dynamic-Range chroma components (.Math., (I)) according to said Standard-Dynamic-Range luma component (y, y.sub.1) and said reconstructed High-Dynamic-Range luma component ().