Abstract: A method for processing image data that employs a stamp field that contains data representing a distance metric for use with a variety of error diffusion operations. The distance metric possesses distance-order preservation permitting the distance from a previous dot to be determined by incrementing the distance metric, without knowing precisely where the previous dot was printed.

Abstract: A process for color quality assessment and color control in a color printing process is provided. The process utilizes a test element array including several test elements is co-reproduced with an image to be reproduced, whereby for the pixels of the image and the test elements of the test element array, color co-ordinate data are present in an original color space and for the test elements of the test element array the color values are present in an assessment color space are present. The co-reproduced test element array is colorimetrically measured with respect to the assessment color space, color difference of the test elements relative to the corresponding set color values are determined from the measured color values of the color elements and a color quality measure is calculated for the reproduced image and/or color correction quantities are calculated for the color reproduction process. The original color space (AFR) is divided into a larger number of color space areas.

Abstract: A system for color gamut mapping includes a control color list for mapping colors between a first color space and a second color space, and also including a processor. The processor is configured to identify a projected color defined in the first color space and map the projected color to a selected color included in the control color list. The selected color is associated with the projected color according to an ocular comparison of the projected color and a printout of the selected color rendered in the second color space.

Abstract: In order to enlarge a gamut in the low-brightness region of the hue of a special color, an image forming apparatus comprises an input unit for inputting color image data for which an image is to be formed; a color separation unit for generating color data in which the color image data has been separated into each of the plurality of colors; and an image forming unit for forming a color image based upon the color data; wherein said color separation unit generates the color data so that the color data has a region in which amount of the color material of the color black used is increased and amount of the color material of the special color used is increased as brightness declines in a low-brightness region in the hue of the special color.

Abstract: A method, computer program product and system for detecting and compensating for color misregistration. A black/white edge or a solid color edge on a target may be scanned. A black/white edge may refer to a black image, e.g., black text, on a white surrounding background having a rapid spatial transition from black to white. A solid color edge may refer to a solid color image, e.g., solid color text, on a white surrounding background having a rapid spatial transition from color to white. A curve of gray values versus spatial pixel positions for each color channel, e.g., red, green and blue color channels, may be generated. A misregistration error may then be calculated by calculating the offset between the color channel curves. The misregistration error may then be used to calibrate the scanner to compensate for the detected color misregistration.

Abstract: A circuit which uses a compressor to divide each separation image into 8-line strips, and to independently compress each strip, a single decompressor to decompress two or more color image separations, strip by strip, by interleaving them, and to apply them to two or more print heads, one for each color separation. DMA from a main memory is used to apply both separations to the decompressor, and the decompressor output is demultiplexed into two print heads, one for each separation. This is done to drive each color separation simultaneously in a single-pass color printer. Multiplexing logic controls the DMA into the decompressor and the output of the decompressor into separate buffers for each color separation. Additional logic uses the page and line sync from each print head to synchronize the accessing of the correct image raster from buffers at the output of the decompressor to the associated print head.

Abstract: Graininess and calorimetric values of color patches formed by an image generating system using dark and light colored recording agents are input to calculate equiluminance contours. Color density decomposition is then performed based on the calculated graininess and equiluminance contours.

Abstract: Systems and computer program products for performing color separation operations. In one aspect, a system creates a high-level representation of a graphical container as a separated element the first time a graphical container is used. The high-level representation being a non-bitmapped representation. The system stores the high-level representation of the graphical container in memory and refers to the separated element in memory when the graphical container is invoked a second time. In another aspect, a system creates a high-level representation of a form XObject as a separated element in a cache. The system uses the separated element in the cache when the form XObject is invoked a second time. In another aspect, a system creates a high-level representation of a pattern container as a separated element in the cache and uses the separated element in the cache when the pattern container is invoked a second time.

Abstract: A separating unit determines, for an image data, whether there exists black data, and generates density data from the black data when the black data exists, and generates color data from data other than the black data. A multinarizing unit converts the color data into multinary data. A magnification varying unit varies the density data and the color data multinarized, using a cubic function convolution method. A binarizing unit binarizes the color data varied, based on a predetermined threshold. An image forming unit prints the color data binarized and the density data varied, onto a recording medium.

Abstract: The present invention provides a method for rotating YUV4:2:0 image in a digital display device, such as TV image system. A YUV4:2:0 image is separated to a Y division matrix and a U and V division matrix. Then the Y division is performed a rotation matrix calculation. And the U and V division matrix is performed a reverse rotation matrix calculation. A rotated YUV4:2:0 image is obtained by combining the processed Y division matrix and the processed U and V division matrix.

Abstract: A color image signal processing device having a high resolution and excellent color reproducibility even though the device comprises a one-chip color sensor. The data format for transmitting image information inputted through an input unit to an output unit includes information on the arrangement of the color filter of the input unit and on the characteristics of the color filter.

Abstract: As a method of calibrating colors other than primary colors such as secondary colors, the contents of an ink color-separation table are reconstructed. However, it is difficult to reconstruct the ink color-separation table within the limitation of total ink amount permissible for a print sheet. Accordingly, a color patch corresponding to a signal value of a color to be calibrated is formed in a printer, then the signal value is calibrated based on a measured color value of the formed color patch and a target value corresponding to the signal value of the color to be calibrated, and calibration multidimensional table data is generated based on the measured color value of the formed color patch.

Abstract: An image processing apparatus in which an appropriate color separation table is selected for an unexpected print medium. In plural color separation tables 108, maximum total color-material color discharge amounts are set to be stepwisely different. A ? correction table 109 is used upon correction of ? characteristics of the respective color-material colors regarding a print medium. A maximum total ink-amount calculation unit 110 calculates a maximum value of total ink amount for each color separation table 108 by using the ? correction table 109. A color separation table selector 107 determines a maximum value approximate to a value set by a maximum total ink-amount setting unit 106 from the calculated maximum values, and selects a color separation table corresponding to the determined maximum value. A color separation processor 102 performs processing based on the selected color separation table.

Abstract: A printer 10 has a reception unit 28 for receiving print commands from a host 12, and has print heads 64, 66 capable of printing multiple colors. A data processing part 24 applies a specific colorization process according to a print command received by a reception unit 28 and generates color print data for printing multiple colors. The content of a colorization process is determined by colorization information stored in a colorization information storage unit 62. The colorization information is set by a data configuration unit 26 according to a color setup command from the host 12.

Abstract: A computer-readable medium of one embodiment of the invention is disclosed that has a data structure stored thereon to represent extended color gamut information for a pixel. The data structure has a number of data fields, where each data field is to store a number of bits representing a different color component of the pixel. The data structure also has at least one interpretation bit for each data field to indicate how the bits of the data field are to be interpreted in representing the different color component of the pixel.

Abstract: A circuit which uses a compressor to divide each separation image into 8-line strips, and to independently compress each strip, a single decompressor to decompress two or more color image separations, strip by strip, by interleaving them, and to apply them to two or more print heads, one for each color separation. DMA from a main memory is used to apply both separations to the decompressor, and the decompressor output is demultiplexed into two print heads, one for each separation. This is done to drive each color separation simultaneously in a single-pass color printer. Multiplexing logic controls the DMA into the decompressor and the output of the decompressor into separate buffers for each color separation. Additional logic uses the page and line sync from each print head to synchronize the accessing of the correct image raster from buffers at the output of the decompressor to the associated print head.

Abstract: A scan method comprising a sensing photo module applicable in a scan apparatus for scanning a document is disclosed. The sensing photo module is equipped with photo sensors parallel to each other and detects the photo signal at every collection distance. The photo sensors extend horizontally and are positioned a line distance between the adjacent photo sensors. Under low operating resolution, the vertical resolution is increased by making the line ratio an integer, in order to solve the problem of color-quality loss due to a non-integer line ratio.

Abstract: A scanner has an imaging device which is constituted by a cold-cathode tube, includes a light source for irradiating light to a reflection surface of a reference white plate and a plurality of pixels arranged in one line, and detects light reflected on the reflection surface by the respective pixels, and has a light source stability determination unit which determines whether or not light amounts obtained by the one line of pixels from the light source are approximately uniform. Only in a case where the light source stability determination unit determines that the light amounts obtained by the one line of pixels from the light source are approximately uniform, the scanner reads the reference white plate to calculate correction values for the respective pixels and reads a manuscript.

Abstract: An image processing device includes a separation unit that separates image information including a first image having plural color components and a second image having a specific color component and to be overlaid at least in part on the first image into a specific color component image of the same color component as the specific color component and an image with color components other than the specific color component among the plural color components; a color conversion unit that performs color conversion of the image with color components other than the specific color component, separated by the separation unit; and a combination unit that combines the color-converted image with color components other than the specific color component, converted by the color conversion unit, and the specific color component image separated by the separation unit.

Abstract: A printed sheet measurement apparatus initially captures images on a reference sheet and a printed sheet to store respective image data. Next, both of the image data are displayed on a display element, and a pair of corresponding points are specified for each of the image data. A judgment is made as to whether or not the pair of corresponding points on each of the images are spaced at least a predetermined distance apart from each other. If not, the corresponding points are specified again. After the corresponding points are determined, the coordinates of the corresponding points are stored. The coordinates of an objective point at which a colorimetric value is to be computed is computed based on the corresponding points. Next, a colorimetric value on the coordinates is measured.

Abstract: Disclosed is a system of image data conversion, capable of setting conversion characteristics with more ease even for data having mixed image attributes, and of reducing the amount of data and the size of memory required. The conversion system includes processing elements in a processor array, each including at least an input data register, character registers, an attribute register, and a global processor, so that a calculator in each of the processing elements operates to select, and store in the character registers, the data set, xi, yi, and ai, corresponding to attribute data stored in the attribute register, to be conversion processed subsequently according to an expression stored in the global processor.

Abstract: A method of detecting sky in a digital color image having pixels is disclosed. The method includes identifying pixels from the digital color image representing an initial sky region; developing a model based on the identified sky pixels, wherein such model is a mathematical function that has inputs of pixel position and outputs of color; and using the model to operate on the digital color image to classify additional pixels not included in the initial sky region as sky.

Abstract: The invention relates to a mapping method, whereby color values of the color image to be mapped, represented in the RGB color space are mapped in the highlight-color color space, corresponding to a projection of the color values in highlight-color. The corresponding calculations are carried out in the RGB color space. A transformation into another color space is not necessary. Furthermore, various corrections are provided, such that a highlight color image is created which is as natural as possible for the human eye.

Abstract: A system and method is provided for characterizing color separation misregistration associated with marking a substrate. The method includes providing an input image having a plurality of patches, each patch having a pattern using a first and second color; marking a substrate with a copy of the input image using a first and second color separation to correspond to the first and second colors, respectively; and measuring a color characteristic of markings of respective copied patches of the copied plurality of patches and generating corresponding colorimetric values. Misregistration of the first color separation markings relative to the second color separation markings is characterized based on the measured calorimetric values.

Abstract: In a black character detection processing, RGB data read from a line buffer is converted into YIQ data. For a subject pixel, a subject area centered on the subject pixel is set, and a judgment pixel that has the lowest brightness in the subject area is set. Then, a judgment area is set as being centered on the judgment pixel. If the absolute values of the averages of chroma components I and Q in the judgment area are both less than the corresponding thresholds T1 and T2, the subject pixel is determined as being an achromatic pixel. Black codes are added to fine-line pixels and edge pixels if the fine-line pixels and edge pixels are determined as being achromatic. Thus, the fine-line pixels and edge pixels can be specified as to be printed in black monochromatic ink. Therefore, black character or similar fine-line or edge part images can be outputted with high quality.

Abstract: A method permitting an end user to recalibrate a color reproduction device. The color reproduction device includes a device for converting the native color values of the scanner into a device independent color space, a test target, and the desired values of each patch of the test target. The method includes printing the test target and scanning it with a scanner that forms a part of the color reproduction device. The device compares the desired values with the values obtained from scanning the printed test target to obtain a set of adjustment values to compensate for drift in the output of the color reproduction device. The compensation emphasizes restoration of the overall gray balance of the color reproduction device and can be implemented by modifying the tone reproduction curves or the halftone process used in the color reproduction device.

Abstract: A write control IC includes a plurality of memories, a plurality of image processing units, a switch control unit, and a plurality of LD control units. The image processing units process image data. The memories store therein the image data. The switch control unit switches the memories to store the image data processed by the image processing units for each of the image processing units. The LD control units obtain the image data from each of the memories and controls LDs to write the image data.

Abstract: Receiving an object color signal and an input black colorant quantity associated with the object color signal, an equivalent output black colorant quantity calculating section calculates an equivalent output black colorant quantity in an output color space equivalent to the input black colorant quantity from the input black colorant quantity. An output color signal determining section calculates an output color signal from the object color signal and the equivalent input black colorant quantity, and determines whether or not the coverage restriction is satisfied. When the coverage restriction is not satisfied, an optimum black colorant quantity is calculated by adjusting the input black colorant quantity, and an optimum color signal satisfying the coverage restriction is calculated to generate an output color signal with the optimum black colorant quantity in the restriction black colorant quantity calculating section and subsequent processings.

Abstract: A method and apparatus for classifying an input image as black and white or color is described. The method calculates a first ratio of a color pixel portion to a total pixel portion in the input image. Next, the method calculates a second ratio of the color pixel portion to a combined pixel portion in the input image, where the combined pixel portion comprises the color pixel portion and a dark black and white pixel portion. Finally, the method returns an indication the input image is black and white if the first ratio is less than a first threshold and the second ratio is less than a second threshold.

Abstract: An image forming apparatus includes a four line CCD which produces RGB data and K data that are read out selectably, and a selector which selects whether to output the RGB data that is provided from the four line CCD. The image forming apparatus also includes a storage part which stores a plurality of patterns, and a judgment part that produces a judgment signal based on a comparison of the RGB data and the plurality of patterns stored in the storage part.

Abstract: An image interpolation method and apparatus by which to quickly generate and display motion pictures using a small amount of data. An image input unit inputs a first image and a second image. A matching processor computes a pixel matching between those images so that a corresponding point is obtained on the second image with respect to a lattice point of a mesh on the first image. The matching processor stores the matching results recorded as a corresponding point file. An intermediate image generator generates an intermediate image between the first image and the second image based on the corresponding point file. In particular, in generating the intermediate image, an attribute of the pixels on one image may be used as such without the attribute being interpolated between pixels of each image. Thus, when generating intermediate images, only one image and a smaller corresponding point file can be used.

Abstract: An image reading apparatus includes an image reading device having a plurality of solid-state image sensing device arrays arranged to be parallel to each other, the image reading device for optically reading an image on an original and a registration adjusting device for performing a position variable process operation to correct a gap of a position to be read on the original, which corresponds to intervals between the solid-state image sensing device arrays.

Abstract: A dark and light color separation of four fundamental colors into color materials containing light ink is realized at high speeds. A cross patch where a discrete color material amount with regard to two kinds of color materials having a different density is distributed in a cross pattern is printed by an image output device. In addition, there are produced a density characteristics map and a color material amount characteristics map. Accordingly, the cell of the equal color material amount is searched within a range not exceeding a target color material use amount from the color material characteristics map and the cell of the equal density is searched within a range not exceeding a target density from the density characteristics map. As a result, it is possible to determine a combination of a color material amount of each of a dark color material and a light color material.

Abstract: Correcting color values for color calibration is disclosed. A sensor measures a color calibration pattern output by a device, to color values for the patch. Corrective action(s) are then performed on the color values. A first such action corrects for measurement corruption of a patch color of the patch resulting from the sensor erroneously measuring adjacent patch colors to the desired patch color. A second action corrects for non-parallel motion of the sensor while measuring the patch. A third corrective action corrects for ambient light detected by the sensor while measuring the patch, without necessarily filtering the sensor. A final action corrects for slow-drift measurement corruption of the patch, by both scaling and offsetting the color values.

Abstract: For each paper type, a plurality of two-dimensional excitation characteristics tables Ti are provided in one to one correspondence with a plurality of colors i. The excitation characteristics table Ti for each color i contains a plurality of sets of excitation-reflectance data Bi (?0, ?) in a two-dimensional matrix form, for a plurality of combinations of incident light wavelengths ? and reflected light wavelengths ?0. The excitation-reflectance data Bi (?0, ?) indicates the ratio of the amount of the reflected light wavelength ?0 generated in response to incidence of the incident light wavelength ?, with respect to the amount of the incident light wavelength ?. Using the two-dimensional excitation characteristics table Ti corresponding to the user's selected paper type and using the spectral radiation characteristics S(?) of the user's selected light source type, Equations (9)-(11) are calculated to create an output profile, and color conversion is performed by using the output profile.

Abstract: An image processing method and image processing apparatus which can execute vector conversion processing by appropriately dividing a clipart image including gradation into regions are provided. To this end, a color document image including a clipart image having an area of gradation is input, the clipart image is selected, and outline information of the clipart image is extracted. The color document image is separated into an achromatic color area and a chromatic color area, which are respectively divided into a plurality of regions. Of the plurality of regions of each of the achromatic color area and the chromatic color area divided in the dividing of region step, regions which meet a set condition are integrated. After that, the clipart image is converted into vector data using a region group after integrating of region and the outline information.

Abstract: A 4-line CCD sensor according to one embodiment of the present invention has a monochromic reading line sensor section and a color reading line sensor section. This 4-line CCD sensor is characterized in that amplification factors for amplifiers 1 to 4 are set so that the amplitude of an output signal from the monochromic reading line sensor section is the same as that of each output signal from the color reading line sensor section. This 4-line CCD sensor is characterized in that the amplification factors for the amplifiers 1 to 4 are set so that the amplitude of each output signal from the color reading line sensor section is smaller than that of an output signal from the monochromic reading line sensor section.

Abstract: A print data generating apparatus to generate print data used for printing in a printing apparatus based on image data representing an image to be printed on a recording medium is provided. The print data generating apparatus comprises a data inputting system, by which application color setting data is inputted in the print data generating apparatus, a color substituting system, in which color information of each of the pixels configuring the image data is substituted with color information of an application color to print each of the pixels configuring the image data based on the application color setting data, and a print data generating system, in which print data to be used for printing is generated based on the image data wherein the color information of each of the pixels is substituted with the color information of the application color in the color substituting system.

Abstract: Separation of a color into values for colorants in colorant space can be done easily when color correction and color separation are done in separate steps, where the color is defined as a set of values in a trajectory space, and trajectories include points for which ink behavior during color separation is known. Colorant values for the color are determined by interpolation using values of the color located in trajectory space, and known values and corresponding colorant values of the trajectory points. Trajectories are preferably color axes dividing the trajectory space into tetrahedral. Colorant values may be corrected using techniques such as colorant replacement or colorant splitting prior to color separation. The color separation process can be calibrated using a test target.

Abstract: A method for determining a number of colors in a digital image includes receiving a digital image and determining a total number of pixels in the digital image. A proportion of the total number of pixels is selected as having an infrequent color and a respective color for each one of a first portion of the pixels is determined. The respective colors are analyzed to determine whether the respective colors include greater than or equal to the selected proportion infrequent color. If the respective colors include greater than or equal to the selected proportion of infrequent colors then a first subsequent process is selected. If the respective colors include less than the selected proportion of pixels having the infrequent color then a second subsequent process is selected. A system for determining a number of colors in a digital image is also described.

Abstract: A color table editing apparatus includes an image data input unit configured to input image data, a color table selection unit configured to select a given color table from a plurality of color tables in association with the input image data, an initial color data generation unit configured to generate initial color data from the selected color table and representative color data including a plurality of predetermined colors, a target color data editing unit configured to edit the initial color data to generate target color data, an optimized color data generation unit configured to generate optimized color data by performing optimization processing based on a color gamut of the edited target color data, and a user interface image display unit configured to display on a 2-dimensional color plane a user interface image including the target color data and optimized color data.

Abstract: A system and method for adjusting the color of an application user interface (UI). A UI allows a user to define hue and saturation values used to adjust first RGB values of pixels determining the color of the UI. A media player application (MPA) calculates second RGB values as a function of the first RGB values and the defined hue and saturation values. The MPA compares the defined saturation value to a threshold saturation value. If the defined saturation value is less than the threshold saturation value, the MPA calculates third RGB values as a function of the second RGB values, and assigns the third RGB values to the pixels determining the color of the UI. If the defined saturation value is equal to or greater than the threshold saturation value, the MPA assigns the second RGB values to the pixels determining the color of the UI.

Abstract: A method for creating and an apparatus for creating a four-dimensional or higher table. A dimension number m and an order n are set, and a permutation of a symbol of n elements and a selecting sequence in accordance with this permutation are determined and set. When one of the n symbols is set as an array element at table position, this setting is started from a first position of all reference axes, and is successively performed to a final position of all the reference axes, and at each position, a symbol unique to each axis direction is selected in the selecting sequence, and at each position of the table, the substitution of a selectable symbol lower in the selecting sequence than the symbol of the determined array element at a position one before an arbitrary position is performed and selection determination is continued.

Abstract: An image data sequencing method for a memory unit inside an optical scanning device. The image data sequencing method is particularly suitable for scanning a line of pixels with each pixel comprising a plurality of primary colors. The image data sequencing method involves scanning a line of pixels to obtain the data for a primary or secondary color. The pixels within the scan line are subdivided into groups. A storage space is reserved both before and after the address space inside the memory unit for holding the scanned primary or secondary color data so that all the primary or secondary color data constituting a pixel are in a fixed sequence next to each other inside the memory unit. When all the primary or secondary color data of pixels within a group are secured, the group of data is released from the memory unit.

Abstract: A method for modifying an input digital image having an (x,y) array of image pixels, each image pixel having an input code value for each of four or more color channels, to produce a depleted digital image subject to a total colorant amount limit. The method includes determining depleted code values for each color channel such that the depleted code values produce substantially the input perceived color according to a device color model.

Abstract: A distortion of a table which causes generation of a pseudo contour is removed. For this, there is disclosed a table creation method of creating a table for performing color separation into coloring material colors in an image forming apparatus, comprising the steps of creating a color separation table of a line in which a color reproduction area of the image forming apparatus is maximized, creating a color separation table in an inner line of the color reproduction area of the image forming apparatus, performing an interpolation process based on the created color separation tables, and smoothing the table obtained by the interpolation process to create the table.

Abstract: An image processing apparatus and an image processing method of the present invention improves image quality during monochrome output by adaptively executional conversion from a color image signal to a monochrome image signal during monochrome image output, and by using outputs from color and monochrome sensors at the same time. Moreover, it lowers the cost of compressing a color signal by using a color sensor with a lower resolution than that of the monochrome sensor.

Abstract: A method for modifying an input digital image having an (x, y) array of pixels, each pixel having an input code value for one or more color channels, wherein said input code value has a nonlinear relationship to colorant amount, to form an output digital image containing output code values for each pixel subject to a total colorant amount limit.

Abstract: A method of color conversion includes providing a first color domain input signal set having plural input signals; sorting the input signals of the first color domain input signal set according to signal intensity; designing and generating plural 1-D look-up table sets for color polyhedrons; selecting a set of look-up tables for use with a specific color polyhedron, wherein said selecting is a function of a section of the polyhedron determined as a function of the input signal set; looking up values in the look-up table set as a function of the input signal set; generating weights as a function of the sorted signal intensities; and interpolating the output from the selected look-up tables as a function of the selected look-up table and the generated weights to produce a color domain signal set which is converted to a desired color domain signal set.

Abstract: A color picture signal processing method includes the steps of: (a) inputting picture signal data; (b) converting the picture signal data to data of luminance Y and color differences Cr and Cb on a Y-Cr-Cb space; and (c) executing a color difference matrix calculation by using at least one pair of equations. By the invention, it may be is possible to obtain a color picture signal wherein a hue circle of a flesh color is suppressed.