In color separation processing by a method that combines a multidimensional LUT and interpolation processing, smooth gradation is implemented by reducing errors accompanying interpolation processing. An image processing apparatus includes a color separation processing unit configured to perform, by interpolation processing using a lookup table having a plurality of dimensions in accordance with signal components of an input image, color separation of an input value that is each pixel value of the input image into an output value corresponding to each of signal components handled by an output device, and each grid point of the lookup table is associated with information representing change characteristics at each portion between adjacent grid points for each dimension of the plurality of dimensions, and in the color separation processing, the interpolation processing is performed based on the information representing the change characteristics.

The occurrence of image quality adverse effects, such as interference fringes and color bleeding, is suppressed for an object including a spot color adjustment-target color. In a case where a spot color adjustment function is made use of, the same color separation table is caused to be applied uniformly, instead of switching color separation tables to be applied to an adjustment-target color depending on whether the object attribute is text/line/graphics, or image.

Embodiments described herein provide for the reuse of some locations in a hash table of color conversions during processing of a print job, while preventing the reuse of other locations. If a determination is made that the hash table is to be re-initialized, then the locations in the hash table that are marked as non-persistent are marked as saved to allow them to be reused, while the locations in the hash table that are marked as persistent are prevented from being reused. During processing of the print job subsequent to re-initialization of the hash table, if a color in the print job does not have a color conversion, then a location in the hash table is identified that is marked as saved. If the location stores the color conversion for the color, then the non-persistent mark is restored for the location to bypass performing a color conversion for the color.

An image processing method includes a first conversion step, a second conversion step that, using a second conversion table for converting input image data represented by a second color space to output image data represented by the second color space, converts image data of a second region for which recording conditions are different from a first region in a second image data, and a recording data generating step that generates recording data based on third image data including image data of a first region in the second image data and image data of the second region after conversion using the second conversion table. When adjusting an ink amount, the ink amount is not adjusted in the second conversion step and is adjusted in the first conversion step.

A method of color mapping color values of an oligochromatic pattern comprising the following steps: determining an image-gamut, in a N-dimensional device independent color system (ND-DICS), of said oligochromatic pattern; wherein said image-gamut comprises said color values of said oligochromatic pattern; and determining a skeleton (500) of said image-gamut; and performing an adaption on said skeleton (500) in said ND-DICS by a set of N-dimensional-transforming steps (30) and determining for points of said skeleton (500), a path in said ND-DICS that corresponds to said adaption; and color mapping said color values, of said oligochromatic pattern, based on said determined paths (35) of said points of said skeleton (500).

A transform wrapper is stored on a memory device and the memory device may be included in a printer cartridge. The transform wrapper may dynamically build a transform map for a printer based on metadata stored at the memory device. The metadata may indicate at least one of a type of depositing material, transform map, print media and printer.

When relation between a color of a color chip (a patch) in a color chart and a color of a color chip in an image-captured color chart is calculated, the color chip of the image-captured color chart was manually extracted by operating a keyboard or a mouse. Such an operation had a problem that an extraction error may occur, and that it takes time to manually extract all color chips in the color chart. The present invention solved the problem by a color chart in which recognition can be easily and automatically executed. The color chart includes a plurality of patches, and an automatic recognition marker configured to automatically recognize at least one of the plurality of patches.

A color measurement apparatus comprising: a color measurement unit configured to perform color measurement of an image on a sheet, the color measurement unit including a light source; a reference member used for calibration of the color measurement unit; a moving unit configured to move the color measurement unit to a first position at which the light source irradiates a region other than the reference member with light and a second position at which the light source irradiates the reference member with light; and a control unit configured to, after causing the light source to emit light when the color measurement unit is positioned at the first position, and then moving the color measurement unit to the second position, execute the calibration based on data obtained by causing the light source to irradiate the reference member with light.

An image forming apparatus includes: a scanner to read each of a first output product serving as a model and a second output product output from the image forming apparatus; a memory that stores a color conversion lookup table to be used when color conversion is performed from a RGB color system into a CMYK color system; and circuitry to correct the color conversion lookup table based on a number of pixels and an amount of change per hue, using read information on the first output product, and re-correct the corrected color conversion lookup table, using read information on the second output product.

The occurrence of image quality adverse effects, such as interference fringes and color bleeding, is suppressed for an object including a spot color adjustment-target color. In a case where a spot color adjustment function is made use of, the same color separation table is caused to be applied uniformly, instead of switching color separation tables to be applied to an adjustment-target color depending on whether the object attribute is text/line/graphics, or image.