Abstract: A color image-scanning device has a fixed scan mode and a flow scan mode. In the fixed scan mode, a document is scanned while maintaining the document at a fixed location on a platen glass. In the flow scan mode, a document is fed from an automatic document feeder and is scanned while moving the document. In each of these modes, images are scanned in a main scanning direction and a sub scanning direction. Color registration errors in the main and sub scanning direction caused by an optical factor are corrected in accordance with correction values stored in a memory. Respective correction values for each of the main and sub scanning directions are acquired by scanning a test chart in each of the fixed-scan mode and the flow-scan mode and stored in the memory. Proper correction values are read from the memory depending on the scanning mode selected, and color registration errors are corrected in accordance with the read correction value.

Abstract: A device and method is provided for generating color data for image formation by converting C, M, Y, data into C, M, Y, K data. The minimum value of the three color values of C, M, Y is selected and, depending on the color of the minimum value, a black data generating table is selected to generate a value for the black color K. The black data generating tables have different black data conversion characteristics from one another and are associated with the three colors of cyan, magenta, and yellow, respectively.

Abstract: A method of processing print data includes the step of maintaining a buffer. Rendered image and graphics objects in a contone layer from a graphics system together with a black layer are received into the buffer. Obscuration of black pixels of the black layer by objects placed on the contone layer is detected. Obscured black pixels are composited with the contone layer if interaction between the black pixels and the contone layer is possible. The contone layer is converted into CMYK specific to a printer. The black layer and the contone layer are compressed and packaged into a page description to be delivered to the printer.

Abstract: An image input/output apparatus having a scanner unit disposed at an upper stage of an apparatus body and a liquid jet recording unit installed at a lower stage of the apparatus body includes a window which light passes through between the scanner unit and the liquid jet recording unit; an exposure controlling unit configured to control linear irradiation by a light source which illuminates an original platen when a maintenance mode of the recording unit is selected; and a luminous flux irradiation unit configured to irradiate a periphery of a liquid jet recording head in the above liquid jet recording unit with a luminous flux emitted from the light source passing through the window.

Abstract: A method of adjusting a non-black primary color value including determining first, second and third portions of the non-black primary color value; determining an adjusted first portion using a first one-dimensional look-up table, wherein the first portion is used as an index to the first one-dimensional look-up table; determining an adjusted second portion using a second one-dimensional look-up table, wherein the second portion is used as an index to the second one-dimensional look-up table; and summing the adjusted first portion, the adjusted second portion and the third portion.

Abstract: During the device link processing, an original lookup table LUT0 is modified into a modified lookup table LUT1 so that achromatic color value sets B2a will be associated with all the achromatic color value sets B1a. Accordingly, during a color conversion processing, by using the modified lookup table LUT1, any input achromatic color value set B1 in (0, 0, 0, K1 in ) will be converted into an output achromatic color value set B2 out (0, 0, 0, K2 out). In this way, the black-print image part in the input image that is reproduced by black ink only by printer A1 will be maintained as a black-print image part and printed by a printer A2 by black ink only. Thus, the black-print information of the input image can be maintained through the color conversion processing.

Abstract: A method of adjusting a non-black primary color value including determining first, second and third portions of the non-black primary color value; determining a first contribution using a first one-dimensional look-up table and the first portion, wherein the primary color value is used as an index to the first one-dimensional look-up table; determining a second contribution using a second one-dimensional look-up table and the second portion, wherein the primary color value is used as an index to the second one-dimensional look-up table; determining a third contribution using a third one-dimensional look-up table and the third portion, wherein the primary color value is used as an index to the third one-dimensional look-up table; and summing the first, second and third contributions.

Abstract: An image reading apparatus is provided which includes a contact image sensor comprised of a plurality of sensor chips arranged in series, an analog image processor for processing an analog image signal from the contact image sensor, a unit for conducting black shading correction for each pixel and a unit for conducting white shading correction for each pixel. The image reading apparatus further includes a unit for digitally monitoring a black offset value corresponding to each chip with respect to the signal that has been processed by the analog image processor and a unit for adding and subtracting a black offset variation amount for each chip in the previous stage of the unit for conducting black shading correction for each pixel, and corrects black offset based on an instruction of a control unit.

Abstract: A gray balancing technique wherein gray balancing curves are determined by interpolating the primary color data values of color samples to determine discrete combinations of primary colors that substantially match predetermined targets, and performing a curve fitting procedure on the discrete combinations of primary colors to produce gray balancing curves.

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: Printing masters are produced by use of an inkjet printing system. The smallest halftone dot size which can be printed by the inkjet printing system is larger than the size of a pixel of the recording grid defined by the addressability of the printing device. Inferior image quality and graininess caused by standard error diffusion algorithms in this system can be counteracted by using a constraint correlation error diffusion system. Out of the complete set of all possible intensity level combinations for reproducing a pixel a subset is selected based upon the multilevel halftoning process of a quantized scalar value which is a function of at least one of the input pixel values of the corresponding colour component pixels. Preferably the scalar value represents the brightness or ink amount allocations.

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 color converting device converts input CMYK data into output color data in a predetermined different format. The color converting device comprises a contrast emphasizing unit emphasizing a contrast of the output color data corresponding to the CMYK data representing a black-character color more than a contrast of the output color data corresponding to the CMYK data representing a non-black-character color.

Abstract: A regulated black colorant amount calculating section calculates a corresponding regulated black colorant amount from the L*a*b* of a plurality of typical color signals in a partial color gamut, which can be represented by three colors excluding black. An optimum black colorant amount modeling section performs color prediction modeling to predict an optimum black colorant amount in a whole color gamut from plural sets of the typical color signal and the regulated black colorant amount. At this time, an extrapolation prediction from a color in a partial color gamut to a whole color gamut is performed to predict the optimum black colorant amount in which a natural color reproduction. By using the color prediction modeling, the optimum black colorant amount determining section determines a corresponding optimum black colorant amount from the L*a*b* of an input lattice point. a YMCK signal calculating section determines residual YMC and outputs a YMCK signal.

Abstract: Input print data can assume one of a RGB color space, CMYK color space, and Gray color space. When graphic arts are principally to be printed, data of these color spaces is converted into CIE Color Space XYZ as a standard color space, and data of the standard color space is converted into a CMYK color space according to the Output Profile of a printer, which then prints the converted data. On the other hand, when office documents are principally to be printed, conversion into the standard color space is skipped, and input color space data is directly converted into a print color space CMYK, and the converted data is then printed.

Abstract: In a system for processing full-color image data, such as within a digital color printer or copier, a four-channel architecture is used. Three of the channels handle image data relating to primary color planes, such as CMY. In the other channel, values relating to the K value which goes with the CMY values for each pixel alternate with a B value, suitable for pure monochrome rendering of the pixel in the image. When it is desired to print or display the image in monochrome, the B values are isolated from the K values.

Abstract: An image pickup apparatus includes an image sensor for photoelectrically converting light incident from a field to produce an image signal via al least two output portions. The temperature of the image sensor is sensed. The image sensor is driven such that the image signal is output via one of the output portions if the temperature sensed is higher than a predetermined value inclusive or is output via the two output portions if the former is lower than the latter. A black level corrector uses, when the image signal is output via one of the output portions, a predetermined single value as a reference to execute black level correction on the image signal, or uses, when the image signal is output via the two output portions, a particular predetermined value as a reference to execute black level correction on each of image signals output from respective output portions.

Abstract: One processing section 131 executes a process of generating image data K representing a black image on the basis of the image data Y, M, and C, and sequentially executes a process of removing elements of the black image contained in the image data Y, from the image data Y, a process of removing the elements of the black image contained in the image data M, from the image data M, and a process of removing the elements of the black image contained in the image data C, from the image data C.

Abstract: A CPU determines whether a generated low-level drawing command is associated with drawing of a gray object and a color value of the gray object is greater than a determination value. If the generated low-level drawing command is associated with drawing of a gray object and the color value of the gray object is greater than the determination value, the CPU executes an overprint drawing process wherein a minimum limit in number of pixels, which causes no defect in a fixing process, is set and a minimum necessary number of pixels are erased (i.e. thinned out).

Abstract: Color processing methods and apparatus are provided that blend the gray component replacement (“GCR”) level of arbitrarily-specified input color data with an estimate of the GCR level of an output profile, and then converts processed device-independent data to output CMYK data that has a GCR level that substantially matches the GCR level of the input CMYK data. Methods and apparatus in accordance with this invention may be used to receive CMYK data that approximates a spot color, and provide tints of spot colors using an output profile that has a GCR level that differs from the GCR level of the input color data.

Abstract: An image reading apparatus includes an imaging unit which has a plurality of channels and which, for the channels, outputs effective signals output from photo-receiving sections for receiving light from a subject, and optical black signals output from light-shielding sections in which the light from the subject is shielded. The image reading apparatus also includes a monitoring unit for monitoring the optical black signal output from the imaging unit, a correcting unit for performing shading correction on the signals output from the imaging unit, and a controller for controlling timing with which the shading correction by the correcting unit is performed. In an image reading method for the apparatus, the shading correction is performed in response to a job start signal, and based on an optical black signal monitored thereafter, the shading correction is performed again.

Abstract: It is difficult to adjust a black plate while maintaining accurate color reproduction in a color printer that forms an image using C, M, Y, and K color agents. Upon generating a conversion condition used to convert a signal on a uniform color space into a CMYK signal which depends on a printer, the signal on the uniform color space according to a colorimetric value is temporarily converted into an RGB signal, and the RGB signal is then converted into a CMYK signal. After that, a black amount adjustment unit (2104) adjusts a K value using a black amount adjustment function based on a user's instruction.

Abstract: An OB level difference is calculated from the luminance signal levels of at least two frames which are exposed for proper exposure time and for exposure time different from the proper exposure time, and the OB level difference is corrected in an input step of a signal processing circuit. Calculation of the OB level difference is performed regularly from immediately after power on of the equipment, the OB level difference obtained in each frame is multiplied, and a value obtained by dividing the multiplied OB level difference by the number of sampled frames is designated as a correction value.

Abstract: Undercolor reduction is performed to a color image that is to be marked to reduce an amount of marking material used to mark underlying colors in overmarked pixels where a top color is marked over at least one underlying color. Information is generated to designate the overmarked pixels. This information may be generated as tags. A raster image is created in which both the underlying and top colors are included in the overmarked pixels. The image data of the raster image is modified such that an amount of marking material used to mark the at least one underlying color in each overmarked pixel is reduced.

Abstract: An image reading apparatus comprises a correction coefficient determining circuit 4 for determining a correction coefficient per each bit of white reference data in a main scanning direction which are read immediately before reading an original image, a correction coefficient modifying circuit 5 for producing a modified correction coefficient, and a correction coefficient predicting circuit 6 for producing a predicted correction coefficient with reference to the modified correction coefficient. If an absolute value of a difference between the correction coefficient and the predicted correction coefficient is smaller than and not smaller than a predetermined threshold value, the correction coefficient modifying circuit 5 produces the correction coefficient and the predicted correction coefficient as the modified correction coefficient respectively. A correction coefficient memorizing circuit 7 memorizes the modified correction coefficient as shading correction coefficient data.

Abstract: A direct device-space-to-device-space transform adjusts the amount of actual black ink, to avoid highlight and midtone granularity in incremental printing—but with no need for translation into perceptual space. If the amount of black ink specified in the input data for a particular color is very small or very large, then that specified color is passed through the transform without substantial change. Thereby the amount of actual black ink and other colorants is held as nearly as practical at levels dictated by device-space input specifications while minimizing visible granularity. Replacement behavior is chosen to smoothly blend between different kinds of operation in different tonal ranges. This system accommodates personnel trained in classical printing-press technologies, who are accustomed to full control over amounts of black and other colorants.

Abstract: This invention provides an image processing apparatus which simplifies the circuit arrangement required for edge emphasis correction.

Abstract: The printer's page description contains a contone layer and a black layer. The black layer is conceptually above the black layer and is composited over the contone layer by the printer. The print driver therefore maintains a page buffer which correspondingly contains a medium-resolution contone layer and a high resolution black layer. It is therefore necessary to determine where an object being placed on the contone layer obscures something on the black layer. When an obscuration occurs the obscured black pixels are composited with the contone layer and removed from the black layer.

Abstract: An open color management system allows any of a plurality of input color devices to share data with any of a plurality of output color devices. The color management system includes a networked connection space for input and output device communication, an input color profile for each input device, an output color profile for each output device, and an open color manager which links a given input device with a selected output device. When linking devices, an input color space dataset having black plus multiple color channels is parsed with the input and output color profiles at a job time to create an output color space dataset having black plus multiple color channels for imaging by the output device without degrading color accuracy while preserving black channel information. A method for open color management and an open color manager for use in an open color management system are also provided.

Abstract: The invention provides a color processing method that is capable of improving the color reproduction accuracy by calculating an adequate amount of black component (referred to as K) with consideration of the coverage restriction when a four-color signal including the black component is generated from a color signal of a input color space. By a YMCK modeling unit, adjustment K calculation unit, restriction K calculation unit and optimal K modeling unit, modeling is performed between the representative color signal and the corresponding optimal K by use of plural color signals that belong to the partial color space, namely the color gamut that is reproducible with three colors and by use of plural color signals that belong to the area on the curved plane that is reproducible with four colors including the black component as the representative color signal. An optimal K determining unit predicts an optimal K corresponding to the input color signal in the input color space based on the model.

Abstract: A method of producing from a first device-dependent image data set, a second image data set matched to a real process, includes, by using inverse gamut mapping, transforming color values from the first image data set into color values of a device-independent color space and, by using gamut mapping, transforming these device-independent color values into the second image data set of an output device; and a color management method including the producing method.

Abstract: To provide an output image of high quality with no graininess produced. An image processing method for controlling a starting point which produces a black component between vertices showing a plurality of chromatic colors and a vertex showing a black in a reproducible color space of a color output apparatus when a look-up table for converting an input color signal into a plurality of color components including a black component is prepared, which controls the starting point producing said black component based on the value of a complementary color component corresponding to a chromatic color which is inconspicuous in the graininess of a black recording material in an output image.

Abstract: A printing control apparatus performs print processing by sequentially spooling print data received from a data processing apparatus via a predetermined communication medium in units of a job and the spooled print data is analyzed in units of a job. The printing control apparatus spools the print data in a memory. When print processing is interrupted during processing of print data which has been spooled in advance, an execution schedule of each spooled job is changed so as to preferentially execute a job of spooled print data capable of being printed by analyzing the cause of the interruption of printing.

Abstract: If a color image is converted into a monochrome image and is sent when the receiver does not have color reception performance, the monochrome image is sent against user's intention. Hence, when transmission of a color image is instructed, a transmission process is controlled to send a color image, send a color image as a monochrome image, or cancel transmission, in accordance with information that pertains to color reception performance of the partner apparatus, and the setup state of a color/monochrome conversion permission switch.

Abstract: In an image processing apparatus, a first recognition section recognizes a black character portion and a color character portion in CMY color signals input from a color conversion section, and outputs a recognition result to a third recognition section. A second recognition section recognizes a low-density region (including a white portion) and a narrow region surrounded by the low-density region in the CMY color signals input from the color conversion section as a low-density region, and outputs a recognition result to the third recognition section. The third recognition section synthesizes the recognition result from the first recognition section and the recognition result from the second recognition section, and delivers a resultant recognition signal to a filtering section, a black signal generating section and a tone processing section.

Abstract: A computerized method for mixing inks to facilitate high fidelity color reproduction for printing includes the steps of using a theoretical printer model to establish relationship between the colorant space and the color space using the small number of measurements; building a simplified colorant space wherein each color in the color space corresponds to only one colorant point; sampling the color space for accurate calibration; performing interpolation and correction for any non-calibrated points based on the theoretical and experimental results; and building a color reproduction table that accepts image data as input and output colorant combinations for use by the printer to achieve high fidelity color printing.

Abstract: An image processor includes: a color conversion unit for converting an input signal to color signals of at least four colors; a gamma correction unit for performing gamma correction on the color signals; a binarization unit for binarizing the color signals through comparison with a threshold value; a superimposing unit for superimposing a color signal of at least one color but of the binarized color signals on another color signal to convert the signals to a superimposed color signal; logical operation unit for performing a logical operation previously defined for an image of three or fewer colors on the superimposed color signal; and a separator for separating color signals as an output of the logical operation unit into separated color signals of at least four colors.

Abstract: Input image data Ki for the black color component is divided into distribution data Tc, Tn, Ty, and Tk for the four color components C, M, Y, and K. The distribution data Tc, Tm, and Ty for the three color components C, M, and Y is combined to the input image data Ci, Mi, and Yi of the three color components C, M, and Y.

Abstract: In a color image processor for converting a RGB input image data into a CMYK image output data, it is determined whether a data format of the input image data is a non-picture image format or a picture image format. For the input image data of the non-picture image format, a color conversion is performed with values of C, M and Y colors made minimum and a value of K color made maximum, when values of all of the R, G and B colors are minimum, and, for the input image data of the picture image format, a color conversion is performed with the values of the C, M and Y colors set to temporary values slightly smaller than the maximum values thereof when values of all of the R, G and B colors are minimum. Final C, M, Y and K colors are obtained by performing the Black-Generation and Under-Color-Removal processing for the temporary values.

Abstract: A light source is turned off (S101), incidence of light on a line sensor is shut off, and the output value of an electric signal output from each of pixels of the line sensor (S102). Since the output value is detected 128 times (S103), random noise can be reduced equal to or less than the variation in the output values for each pixel of the line sensor. The output values detected by a detection section are added up by an average value difference calculation section (S104). The sum total of the output values is divided by the number of detection times (S105) to calculate the average value of the output values (S106). The average value difference calculation section calculates the difference between a setup value and the average value as an average value difference (S107) and the average value difference is stored in black reference memory for each pixel (S108).

Abstract: For converting color data to be processed by a first device into color data to be processed by a second device, using a color conversion table, a constraint condition is set between the color data, and a color conversion table between at least portions of the color data is generated according to the constraint conditions, whereas a color conversion table between remainders of the color data is generated in calorimetric association therewith.

Abstract: When a first mode is designated, an RGB image signal obtained by reading an image is compressed, decoded and stored. After that, the resultant signal is converted into a CMYK image signal on the basis of a first color conversion system, and an image based on the YMCK image signal is formed on a medium. When a second mode different from the first mode is designated, an RGB image signal obtained by reading an image is directly converted into a CMYK image signal on the basis of a second color conversion system, and an image based on the YMCK image signal is formed on a medium.

Abstract: An image processing apparatus includes a communication unit configured to exchange data with an external device, an attribute determination unit, an embedding unit, and a storage unit. The attribute determination unit determines an image attribute of a first image signal to generate an attribute signal indicating the image attribute. The embedding unit embeds the attribute signal in the first image signal in a predetermined format to obtain a second image signal. The storage unit stores the attribute signal and one of the first image signal and the second image signal. The second image signal is transmitted to the external device through the communication unit.

Abstract: An image processing apparatus reads an original by R, G and B sensors and a monochromatic sensor, and includes Log conversion means for subjecting signals produced by the reading to Log conversion. When two-color printing is performed, Log conversion parameters are individually set for one of signals produced by the reading of the R, G and B sensors and for a signal produced by the reading of the monochromatic sensor.

Abstract: An image preprocessing apparatus, which processes image signals of an image of a scanned object, includes an image sensing module, a multiplexing unit and an analog signal processor. The image sensing module includes a number of monochrome image sensors, as well as a black-and-white (B/W) image sensor, outputting a number of monochrome analog image signals and a B/W analog image signal respectively. The multiplexing unit receives the B/W analog image signal and some of the monochrome analog image signals and then selects either the B/W analog image signal or these monochrome analog image signals as the output of the multiplexing unit. The analog signal processor receives the output of the multiplexing unit and the monochrome analog image signals that are not received by the multiplexing unit, and outputs a digital signal.

Abstract: When color image data (C1, M1, Y1) representing a color image is read in S11, the minimum value from among the color values C1, M1, and Y1 is selected in S12. Next, in S13, black data K1 is generated using a black data generating table that corresponds to the color of the minimum value k=min (C1, M1, Y1) determined in S11. The black data generating tables have different black data conversion characteristics from one another and are associated with the three colors of cyan, magenta, and yellow, respectively. In S14, the black data K1 obtained in S13 is subtracted from each of the color data C1, M1, and Y1 to obtain corrected color data C2, M2, and Y2. In S15, the data C2, M2, and Y2 are outputted along with the black data K1 as four-color data (C2, M2, Y2, K1).

Abstract: The present invention provides a color image processing system for processing drawings at high speed while reproducing color tone with fidelity. The color image processing system includes a digital processor that performs a raster operation on multigradation image data and generates an output image represented by a first plurality of color components. The system also includes a processor which separates the output image data into a second plurality of color components and stores the separated data in a memory. The system includes a reverse color separator which transforms the stored image data back into image data represented by the first plurality of color components and supplies this transformed image data to the digital processor. In a preferred embodiment, the digital processor performs an under color removal/black generation conversion to separate the output image data resulting from the raster operation into cyan, magenta, yellow and black color components.

Abstract: A gradation correction curve creation apparatus for creating gradation correction curves for improving color reproducibility in UCR process includes a first gradation correction curve creation section creating a first gradation correction curve based on measured density values and target density values of monochromatic patches, a second gradation correction curve creation section creating a second gradation correction curve 2based on measured calorimetric values and target calorimetric values of gray patches, a start position calculation section calculating start positions on the first and second gradation correction curves at which the gray component in color mixture starts replacement with K through UCR process, and a gradation correction curve combining section creating a third gradation correction curve by smoothly connecting the more shadowed side of the first gradation correction curve than the start position and the more highlighted side of the second gradation correction curve than the start position.

Abstract: Transformation of CMYK source color data from a source device into CMYK destination color data for rendering by a destination device, in a case which the “K” channel of the CMYK source color data was generated by a source black generation algorithm. A source color profile corresponding to the source device and a destination color profile corresponding to the destination device are accessed. The source color profile contains a first transform and a copy of or reference to the source black generation algorithm; the destination color profile contains a second transform.

Abstract: An image processing apparatus includes an edge detecting portion for detecting an edge area of an input image signal and a lightness and chroma detecting portion for detecting a low lightness and low chroma area of the input image signal. An image processing such as edge emphasizing is performed for the edge area of black letters or lines decided by the detection signals of the edge detecting portion and the chroma detecting portion. The image processing apparatus further includes an edge enlarging portion 6 for enlarging the edge area detected by the edge detecting portion 4 and circuits 12 and 19 for converting color image data C, M and Y and black image data K so that C, M and Y color densities in the enlarged edge area is decreased and a black densities is increased. Thus, supporting a high definition, color drift in the edge portions of the black letters or lines of the color image becomes inconspicuous, so that the reproducing quality is improved.