Abstract: An apparatus and method for converting color data are provided. The method includes generating a CMYK color gamut extended from a CMY color gamut that consists of a cyan (C) colorant, a magenta (M) colorant, and a yellow (Y) colorant, by use of the CMY color gamut and a black (K) colorant; mapping input colors using the generated CMYK color gamut; converting color data of the mapped input colors to CMY data; and converting the CMY data to CMYK data. Accordingly, natural representation and printing of low-lightness colors and high-saturation colors can be attained.

Abstract: A gamut mapping method and apparatus are provided which allow a reproduction device to properly represent colors that are not within a gamut boundary of the reproduction device but within in a gamut boundary of a source device. The gamut mapping method includes (a) setting a cut-off rate for a predetermined color component and defining a cut-off region on a standard color circle; (b) determining a gamut of a reproduction device using color data which is part of basic color data and corresponds to colors that do not belong to the cut-off region; (c) modifying a gamut of a source device according to the determined gamut of the reproduction device; (d) determining a mapping relationship between the modified gamut of the source device and the determined gamut of the reproduction device; and (e) creating a mapping table based on the determined mapping relationship.

Abstract: An apparatus and method for image-adaptive color reproduction is provided. The apparatus includes an information-extraction unit, an image-compression unit and an image-information-reproduction unit. The information-extraction unit inputs image information of a first color space model, converts the input image information into image information of a second color space model, and extracts pixel frequency information of pixels belonging to a plurality of color regions by using the image information of the second color space model. The image compression unit inputs the image information of the first color space model, converts the input image information into the image information of the second color space model, and calculates compressed image information by compression-mapping the image information of the second color space model. The image information reproduction unit outputs final image information by using the pixel frequency information and the compressed image information.

Abstract: An image processing method and an image processing apparatus to calibrate a scan image include selecting any one of a plurality of colors having different gray reproduction characteristics, and calibrating the scan image based on a color table corresponding to the selected color among a plurality of color tables.

Abstract: A color data conversion apparatus and method. The color data conversion apparatus includes a K ratio calculator for outputting a K ratio that is calculated using entered color data; a K ratio adjuster for adjusting the calculated K ratio, which is output from the K ratio calculator, in reference to gamut boundary descriptors (GBDs) corresponding to a K ratio and outputting the adjusted K ratio as a final K ratio; and a CMY ratio calculator for calculating C, M, and Y ratios based on the final K ratio. When converting the entered color data to the CMYK data, the calculated K ratio can be adjusted to the K ratio printable by use of the K GBDs. Accordingly, the printing apparatus can substantially print according to the calculated K ratio and thus the degradation of the printing quality can be avoided.

Abstract: Apparatuses and methods for performing gamut compression. A gamut mapping apparatus of the invention includes a gamut analyzing unit for analyzing the gamut of a source device and the gamut of a target device using a gamut information profile; a gamut compressing unit for mapping original images of the source device within the gamut of the target device by using the analytical information on the gamuts; and a gamut extending unit for increasing the chroma of predetermined images among the compressed original images on the basis of the analytical information on the gamuts and the performance result of the gamut compressing unit.

Abstract: A color correction apparatus of a scanner and a method of controlling the same. The color correction apparatus changes data existing outside of the gamut boundary to the other data existing within a gamut boundary in order to correctly express a gamut, and correctly corrects the color of the scanner. The color correction apparatus includes a calculator to calculate CIE data corresponding to RGB data, and a correction unit to change the CIE data to new CIE data existing within a gamut boundary if it is determined that the CIE data exists outside of the gamut boundary.

Abstract: In a color printing system the printer driver automatically obtains local characteristic information, such as countries, cities, languages, etc., stored in the OS of the host computer. The printer driver or the image forming apparatus color-converts the input data into output data, which reflects the color preference of the specific region where the image forming apparatus is installed, by using the look-up table corresponding to the local characteristic information obtained by the printer driver. Accordingly, the color preference of the specific region, in which the image forming apparatus is installed, is set more quickly and easily without requiring a complicated structure.

Abstract: A classifying of an input image into a business graphic image or a photo image, such as in image calibration of the image. A system classifying an input image into at least one of a business graphic image and a photo image includes a color space transform unit transforming the input image into components of a lightness-saturation color space, a lightness analysis unit calculating a lightness frequency distribution of lightness components among the transformed components, a saturation analysis unit calculating an average of saturation components among the transformed components, and an image classification unit comparing an estimation function using the calculated lightness frequency distribution and the average of the saturation components and a threshold value so as to classify the input image.

Abstract: A color-management apparatus and method which can improve color reproducibility during color-gamut mapping of devices having different color gamuts are provided. The apparatus includes a transformation unit transforming a first color space of an original image supplied from a source device into a second color space, a computing unit computing a plurality of second parameters based on at least one among a plurality of first parameter defining the second color space, and a color-gamut mapping unit performing color-gamut mapping between the source device and a reproduction device reproducing an output image from the original image using the plurality of second parameters.

Abstract: A color image scanning system, method and medium that generates look-up tables for color data correction based on the type of printing paper and the kind of image on the printing papers, thereby improving color reproducibility upon scanning. A color image scanning system may include a storage unit to store look-up tables having correction values of first color data, obtained by scanning a first printing paper having a plurality of color patches, each of the look-up tables corresponding to a type of printing paper, and a final image generation unit to correct second color data, obtained by scanning a second printing paper, with reference to a look-up table of the look-up tables, the look-up table corresponding to the type of printing paper used by the second printing paper.

Abstract: A system, medium, and method calibrating gray data. The system calibrating gray data includes a transformation unit to transform red, green, and blue (RGB) data of a source device into transformed color data of a different color space using a color appearance model, and a calibration unit to map a chroma value of gray data, corresponding to the transformed color data, in the different color space to a predetermined value to generate calibrated color space data.

Abstract: Provided is a method and apparatus to perform gamut mapping between heterogeneous devices, more particularly, a method and apparatus to map a color of a device to an identical or visually and sensually preferable color of another device having a different color gamut. The method includes adjusting lightness of a color of a source device by scaling to match a lightness range of the source device with a lightness range of a destination device; modifying the adjusted lightness of the color of the source device by adjusting a color gamut of the source device to a color gamut of the destination device; and to map the modified color of the source device to a color in the color gamut of the destination device.

Abstract: An apparatus and method for image-adaptive color reproduction is provided. The apparatus includes an information-extraction unit, an image-compression unit and an image-information-reproduction unit. The information-extraction unit inputs image information of a first color space model, converts the input image information into image information of a second color space model, and extracts pixel frequency information of pixels belonging to a plurality of color regions by using the image information of the second color space model. The image compression unit inputs the image information of the first color space model, converts the input image information into the image information of the second color space model, and calculates compressed image information by compression-mapping the image information of the second color space model. The image information reproduction unit outputs final image information by using the pixel frequency information and the compressed image information.

Abstract: A gamut-mapping apparatus includes a color-coordinate-conversion module which converts color coordinate values of an inputted color sample to values of a spherical coordinate system, and which divides the spherical coordinate system into a predetermined number of segments; a judgment module which detects color coordinate values having a largest radius among color coordinate values included in the divided segments; and a gamut-boundary-setup module which detects the color coordinate value having a greatest radius, which is most adjacent to a center of each segment, according to the divided segments based on the detected color coordinate values having the largest radius among color coordinate values included in the divided segments, and which sets a gamut boundary. The spherical coordinate system is divided based on a hue value and a largest chroma value with respect to each hue.

Abstract: An apparatus and method for compensating an output image are provided. The apparatus includes an output image estimation module which estimates an output image for an original image using a lookup table (LUT) that maps one color space to another color space, an error detection module which detects an erroneous patch from the estimated output image, and an LUT compensation module which compensates the LUT based on the detected patch.

Abstract: A host apparatus, system, and method are provided for reproducing color by predicting change in color of an image according to chromaticity of various observation light sources. The host apparatus includes: a lookup-table-generation module generating mapping information with regard to an image having a format and a calibrated image, which corresponds to the image and is calibrated according to an observation light source; and an image calibration module calibrating an input original image according to an observation light source selected by a user based on the mapping information.

Abstract: A gamut mapping method and apparatus are provided which allow a reproduction device to properly represent colors that are not within a gamut boundary of the reproduction device but within in a gamut boundary of a source device. The gamut mapping method includes (a) setting a cut-off rate for a predetermined color component and defining a cut-off region on a standard color circle; (b) determining a gamut of a reproduction device using color data which is part of basic color data and corresponds to colors that do not belong to the cut-off region; (c) modifying a gamut of a source device according to the determined gamut of the reproduction device; (d) determining a mapping relationship between the modified gamut of the source device and the determined gamut of the reproduction device; and (e) creating a mapping table based on the determined mapping relationship.

Abstract: A method and apparatus that outputs an optimally-converted image using predefined data and color characteristics. The method includes: receiving the color characteristics; converting the received color characteristics into a range of lightness; converting the range of lightness and the received color characteristics into a gamut of lightness and chroma to be represented by the printer; and adaptively outputting the image according to the converted range of lightness and the received color characteristics.

Abstract: A color data conversion apparatus and method. The color data conversion apparatus includes a K ratio calculator for outputting a K ratio that is calculated using entered color data; a K ratio adjuster for adjusting the calculated K ratio, which is output from the K ratio calculator, in reference to gamut boundary descriptors (GBDs) corresponding to a K ratio and outputting the adjusted K ratio as a final K ratio; and a CMY ratio calculator for calculating C, M, and Y ratios based on the final K ratio. When converting the entered color data to the CMYK data, the calculated K ratio can be adjusted to the K ratio printable by use of the K GBDs. Accordingly, the printing apparatus can substantially print according to the calculated K ratio and thus the degradation of the printing quality can be avoided.