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: The color image processor in accordance with the invention has a raster circuit 1 for receiving data about an image of multiple gray levels of plural colors, an UCR/BG circuit 2 for decomposing the image data received from the raster circuit 1 by the use of input Raster Operation codes according to color materials of plural colors, rasterizing the image data into a buffer memory 5, and generating black, and a binarization circuit 3 for binarizing raster data about each gray level and converting the data into data about images each having one gray level. If the aforementioned Raster Operation codes are other than Raster Operation codes having a base image, the raster output function, the UCR/BG functions, and the binarization function are performed simultaneously.

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: 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: A black amount/solid color amount determination section determines a black amount K and a solid color amount O from an input L*a*b* color signal and transfers K and O to a YMC determination section and an image record signal output section. The YMC determination section determines YMC color signal of an image output unit colorimetrically matching the L*a*b* color signal input under a condition that the black amount is K color signal and the solid color amount is O color signal from the input L*a*b* color signal and the KO color signal input from the black amount/solid color amount determination section, and transfers the YMC color signal to the image record signal output section. The image record signal output section outputs the KO color signal input from the black amount/solid color amount determination section and the YMC color signal input from the YMC determination section.

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: A printer with synchronized engine/controllers is disclosed. The printer has a multi-segment printhead. Each engine/controller (10) configured to be coupled with others to drive the printhead (33). Each engine/controller (10) has an interface (27) at which to receive compressed page data. Image decoders (28, 88) decode compressed image planes image decoders to perform an expansion, in pipeline fashion, for the received compressed page data. A half-toner/compositor (29) composites respective strips of the decoded image planes and sends output to a printhead interface (32). A printhead interface (32) interfaces with the printhead. A synchronization signal generator (89, 90) may output a synchronization signal that is used to synchronize print engine/controllers.

Abstract: A print engine/controller (10) configured to be coupled with others to drive an ink drop printhead (33). It has an interface (27) at which to receive compressed page data. Image decoders (28, 88) decode compressed image planes image decoders to perform an expansion, in pipeline fashion, for the received compressed page data. A half-toner/compositer (29) composites respective strips of the decoded image planes and sends output to a printhead interface (32). A printhead interface (32) interfaces with the printhead. A synchronization signal generator (89, 90) may output a synchronization signal that is used to synchronize print engine/controllers. One printhead interface (32) preferably acts as master generating the synchronization signal to synchronize all the print engine/controllers to drive the printhead at any one or more of higher speed, higher input resolution, higher outlet resolution or wider format.

Abstract: A printer with a multi-segment printhead has multiple engine/controllers (10) configured to be coupled with other engine/controllers to drive the printhead (33). The controllers each have an interface (27) at which to receive compressed page data. Image decoders (28, 88) decode compressed image planes image decoders to perform an expansion, in pipeline fashion, for the received compressed page data. A half-toner/compositer (29) composites respective strips of the decoded image planes and sends output to a printhead interface (32). A printhead interface (32) interfaces with the printhead. A synchronization signal generator (89,90) may output a synchronization signal that is used to synchronize print engine/controllers. One printhead interface (32) preferably acts as master generating the synchronization signal to synchronize all the print engine/controllers to drive the printhead at any one or more of higher speed, higher input resolution, higher outlet resolution or wider format.

Abstract: A print engine/controller (10) configured to be coupled with others to drive an ink drop printhead (33). It has an interface (27) at which to receive compressed page data. Image decoders (28, 88) decode compressed image planes in the received compressed page data. A half-toner/compositer (29) a half-toner/compositer composites respective strips of the decoded image planes by halftoning a contone layer to a bi-level version and compositing a spot1 bi-level layer over an appropriate halftoned contone layer. A printhead interface (32) interfaces with the printhead. A synchronization signal generator (89,90) outputs a synchronization signal that is used to synchronize print engine/controllers. In some embodiments, one printhead interface (32) acts as master generating the synchronization signal to synchronize all the print engine/controllers to drive the printhead at any one or more of higher speed, higher input resolution, higher outlet resolution or wider format.

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 printing technique wherein pixel locations that are requested to be marked with only black are identified, black is applied to the identified pixel locations, non-black color is applied to a subset of the identified pixel locations that have an associated black half-tone threshold level that is darker than a predetermined non-white threshold level, such that only black is applied to identified pixel locations having an associated black half-tone threshold level that is lighter than or equal to the predetermined non-white threshold level.

Abstract: An integrated circuit fabricated on a single substrate. The integrated circuit includes a data bus and purpose-specific functional units connected to the data bus. The functional units include a JPEG decoder, a compressed bi-level expander, a halftoner, and a printhead interface. A general-purpose processor may also be connected to the data bus for controlling the functional units. The processor may be connected to run software that coordinates the functional units to receive, expand and print pages.

Abstract: A gray balancing technique wherein color data values are modified only if the color data values include a gray component.

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 method, system and computer article are presented for smoothing an image calibration signal in order to smooth a reproduced signal, and to identify the presence of any remaining spikes or other significant deviations. The invention recognizes the problems with raw calibration signals, and posits that the calibration signals be filtered by methods and systems described. For example, calibration data may be smoothed by fitting the calibration data to a parametric model employing either linear or non-linear least squares. Alternate techniques implement smoothing using optimal filtering. An aspect of the invention is a method, computer product or article of manufacture for improving an initial calibration profile having an initial profile extent to form an improved calibration profile. The initial profile may be formed for a scanner employing a linear array CCD and having a particular direction of motion.

Abstract: A digital printing system that includes a personal computer and a printer. The computer includes a printer driver that receives and compresses print data. The printer is connected to the personal computer and includes a data expansion system and a page-width color inkjet printhead. A transmission system is connected to both the personal computer and to the printer for transmitting the compressed print data from the personal computer to the data expansion system of the printer.

Abstract: A method of printing and the related printer architecture for receiving compressed page data that includes both contone data and foreground bi-level data. Both the contone data and the foreground bi-level data are decompressed. The contone data is halftoned to bi-level color data. The foreground bi-level data is composited over the bi-level color data to create composited bi-level color image data that is then printed. The related printer architecture includes an integrated circuit that includes a processor bus and purpose-specific functional units each connected to the processor bus. The functional units include a JPEG decoder, a bi-level decoder, a halftoner, and a program ROM. A general-purpose processor is connected to the processor bus for controlling the functional units. The processor runs software that coordinates the functional units to receive, expand and print pages.

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: An image reading apparatus for reading an image using a monochrome image sensor and a color image sensor having three shift registers which requires a reduced manufacturing cost and is less affected by the influence of external noises. The image reading apparatus comprises an analog frontend IC with three channels and having programmable gain amplifiers (PGA) for the respective channels capable of adjusting gains, an analog/digital converter (ADC) and a multiplexer (MUX) for sequentially providing signals amplified by the respective PGAs to the analog/digital converter built-in. The image reading apparatus amplifies pixel signals output from the respective channels of the monochrome image sensor or the color image sensor by providing the pixel signals to the corresponding PGAs, and converts the amplified pixel signals into pixel data through the analog/digital converter.

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 nedium-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: It is necessary that paper be moved past the printhead at a constant velocity to obtain artifact-free printing. Therefore the printhead requires a constant stream of data during printing. Whilst it is possible to rasterize the page using a page description language directly to the printhead, it is uneconomical. Hence the redering is carried out in the PC. However, the standard USB peripheral connection is the standard connection on PCs, which places a constraint on the limit of data per page that can be transmitted to the printer and still obtain a reasonable rate of printing. Thus the contone images and graphics are rendered in the PC to a pixel level, and the black text and graphics are rendered in the PC to a dot level, where the rendered data is compressed and transmitted to the printer. The transmitted data is decompressed and combined and the images overlaid and printed.

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: 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 nedium-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 image processing apparatus having a first black generating unit for generating a black component from input image data of signals representative of a plurality of color components, a color correcting unit for correcting the colors of the signals representative of the plurality of color components and a signal representative of the black component and outputting the color corrected signals representative of the plurality of color components, and a second black generating unit for generating a signal representative of a black component from the color corrected signals.

Abstract: It is necessary that paper be moved past the printhead at a constant velocity to obtain artifact-free printing. Therefore the printhead requires a constant stream of data during printing. Whilst it is possible to rasterize the page using a page description language directly to the printhead, it is uneconomical. Hence the redering is carried out in the PC. However, the standard USB peripheral connection is the standard connection on PCs, which places a constraint on the limit of data per page that can be transmitted to the printer and still obtain a reasonable rate of printing. Thus the contone images and graphics are rendered in the PC to a pixel level, and the black text and graphics are rendered in the PC to a dot level, where the rendered data is compressed and transmitted to the printer. The transmitted data is decompressed and combined and the images overlaid and printed.

Abstract: A color image processing apparatus includes a first unit that predicts a bleeding occurrence level from input image data, a second unit that replaces pixels in a given area including boundaries between black ink and any of color inks with another pixels in accordance with the bleeding occurrence level, and a third unit that controls switching of multiple printing modes for each main scan in accordance with the bleeding occurrence level.

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 combined profile is created through a first step of deriving a coordinate component of a black on a color space for CMYK dot % for a printer associated with a predetermined representative coordinate in the color space for CMYK dot % for printing, on the representative coordinate, based on a printing profile and a printer profile; a second step of deriving a coordinate component of the black on the color space for CMYK dot % for a printer associated with coordinates other than the representative coordinate, based on the coordinate component of the black associated with the representative coordinate; and a step of deriving coordinate components of cyan, magenta and yellow on the color space for CMYK dot % for a printer, on the coordinates corresponding to the coordinate components derived in the first and second steps, based on the derived coordinate components of the black, the first and second color conversion definitions.

Abstract: An image processor includes an input unit which inputs color image data, and a color correction unit which effects under color removal processing and black generation processing on the color image data conforming to the characteristic of a recording medium, and outputs data indicative of a plurality of color components including a black component. The color correction unit effects the under color removal processing and the black generation processing so that the total output level of the data indicative of the plurality of color components including the black component may assume a value conforming to the color image data.

Abstract: The present invention is directed to an improved system and methodology for generating ink/media transforms. A preferred methodology comprises one or more of the following steps: selecting the ink type; selecting the color set; selecting the media type; selecting the ink saturation level; generating a set of “linearization” color samples, or “ramps”; measuring the linearization ramps; generating a set of “target” color samples, or “patches”; measuring the target patches; screening the target patches and generating the boundary surface of a printer's gamut; implementing an under-color removal (UCR) and black generation (BG); and building the Printer Profile, Transforms and ICC Color Profiles.

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: In an image processing method, a tone of a target pixel and tones of peripheral pixels around the target pixel are detected. Also, a tone difference between the target pixel and each peripheral pixel is detected. Then, smoothing processing is executed upon image data of the target pixel, based on the tone differences between the target pixel and the peripheral pixels, in such a way as to reduce a change of the tone of the target pixel.

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

Abstract: A method of error diffusion selects colorants, from a plurality of colorants defining a color space, to obtain an actual color which represents a desired color for respective pixels. The actual colors are output by an output apparatus. The process first determines the desired color for a pixel. Next, undercolor removal is performed for the desired color, thereby dividing the desired color into first and second components. A scalar error diffusion is then performed for the first component of the desired color, resulting in a first component of the actual color. A vector error diffusion is performed for the second component of the desired color. The vector error diffusion calculates an error as a negative of a distance in the color space between a closest available colorant in a subset of the plurality of colorants and the desired color. The error is added to the desired color to obtain a second component of the actual color.

Abstract: Input image information undergoes color conversion processing in a color conversion section 1, then is separated into first piece of image data, second piece of image data, and selection data in a multilayer data processing section 2 and transmission data in the multilayer data format is output. On the other hand, a 1-layer data processing section 3 prepares transmission data in the normal 1-layer data format from the image information. A color determination section 4 determines whether the input image information is a color or monochrome image. If the image information is determined a color image, a selection section 6 selects the transmission data in the multilayer data format; if the image information is determined a monochrome image, the selection section 6 selects the transmission data in the 1-layer data format. Then, it transmits the selected transmission data through a transmission section 7.

Abstract: An image processing apparatus which includes an image signal input device for outputting a first image signal including at least three signals corresponding to cyan, magenta and yellow, respectively, an image signal converter for converting at least one of the signals included in the first image signal into N (N is an integer greater than one) second image signals corresponding to N inks of different concentrations of a same color family, a black abstraction device for performing black abstraction on each of N second image signals individually to produce a third signal, and a signal processor for performing a UCR processing and black inking processing on the second and third signals to produce fourth signals.

Abstract: A method, system and computer article are presented for smoothing an image calibration signal in order to smooth a reproduced signal, and to identify the presence of any remaining spikes or other significant deviations. The invention recognizes the problems with raw calibration signals, and posits that the calibration signals be filtered by methods and systems described. For example, calibration data may be smoothed by fitting the calibration data to a parametric model employing either linear or non-linear least squares. Alternate techniques implement smoothing using optimal filtering. An aspect of the invention is a method, computer product or article of manufacture for improving an initial calibration profile having an initial profile extent to form an improved calibration profile. The initial profile may be formed for a scanner employing a linear array CCD and having a particular direction of motion.

Abstract: To obtain conversion condition which enables color reproduction with high precision based on a nonlinear output characteristic of an output device. In order to generate a conversion condition for converting data in a color space independent of a device into data in a color space dependent on a device, a condition for restricting the amount of recording material is set, an output value of a solid on which a color reproducible by an output device in a three-dimensional color space is defined is computed based on the set condition, and the conversion condition is generated based on the colorimetry value of the color reproduced by the output device corresponding to the computed output value.

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: A print drive that is placed in a prepress workflow between a raster image processor and an output device receives first and second raster data corresponding to first and second image data, and processed by the raster image processor. The print drive uses the second raster data to modify the first raster data. In one embodiment, the first raster data is digitally combined with the second raster data using a digital doublebumer. In another embodiment, a digital masker uses the second raster data as a mask to selectively delete a portion of the first raster data. When used in succession, the digital masker and the digital doubleburner permit the editing of raster data which is rendered through the output device as a modified printed image.

Abstract: When it is determined that a film original is at least one of an under-exposed negative film and a high sensitive film, the image processing method and apparatus separate the input image signals into at least three kinds of frequency components composed of lowest frequency components a band of which is made more narrower, frequency components containing high frequency components and at least one kind of remaining frequency components, enhance frequency components containing the high frequency components, suppress at least one kind of frequency components of the remaining frequency components and synthesize both of enhanced and suppressed frequency components and the lowest frequency components. The method and apparatus are capable of obtaining a reproduced image having good image quality by suppressing graininess and further improving the reproduced image particularly in the under-exposed negative film and the high sensitive negative.

Abstract: An apparatus for simultaneously reading images on both sides of the document sheet as the sheet having images on both sides is moved through the apparatus, one side read by a CCD sensor and the other side read by a contacted image sensor. An image synthesizing unit synthesizes image data from the CCD sensor and image data from the contacted image within one cycle of main scanning by the two image reading units. Furthermore, image processing circuits in the subsequent steps perform specific modes of processing on the data within one cycle of main scanning. That permits simultaneous reading of both sides of the sheet document without reducing document reading speed and expansion of the image processing unit.

Abstract: A color-to-monochrome image conversion technique is disclosed. After the color image is converted to a monochrome input image and a plurality of primary-color input images, boundary information is extracted from the plurality of primary-color input images. The boundary information discriminates between different colors with the same lightness in the color image. Thereafter, the boundary information is superimposed as a binary image on the monochrome input image to produce the monochrome image. Therefore, a boundary between different colors with the same lightness can be easily imagined and be visibly displayed.

Abstract: An image processing system for executing a color process on color image data and generating output color image data composed of a plurality of color component data including black component data, the system using a mode for generating the output color image data such that, when input color image data is an achromatic color, color component data other than black component data in the output color image data are substantially zero-valued. The system includes setting, based on an instruction from a user, relationships between a plurality of types of object images and the mode, inputting object image data of an input image, discriminating the type of the object image data, and executing the color process on color image data of the object image data using the mode based on the setting step and the type discriminated in the discriminating step.

Abstract: An image reading system prescans and/or scans a film with magnetic recording and image data to be stored in a film cartridge after the film is developed. The image reading system employs a one-dimensional CCD and is capable of recording/reading retrievable ID numbers on a magnetic recording part. A thumbnail display simultaneously displays all image and magnetic information of all frames of a film, and selected frames to be scanned can be easily identified and compared after obtaining the image data of such film through prescanning. Magnetic recording-information and image information are rapidly read during prescanning and selected frames are then scanned with more refinement as compared to the coarse scanning of the film during prescanning.

Abstract: Toner/ink is saved while still being able to print any given color value within the full color gamut of a given printer. Combinations of varying percentages of a printer's toners/inks (cyan, magenta, yellow and black) are determined for maximum black substitution with varying percentages of under color addition (UCA) (e.g., 0%, 50%, 80%, and 100%). Patches of varying combinations of CMYK using maximum black substitution and a given percentage of UCA are printed out, and the color value (L*a*b*) of each patch is measured. Tables are generated having the percentage amounts of C,M,Y, and K and the corresponding measured color value. A first table represents maximum black substitution with 0% UCA. If a desired color value falls within this table, the corresponding CMYK combination represents the most toner/ink that can be saved. If a desired color value does not fall within the first table, subsequent tables representing increasing percentage amounts of UCA are examined.

Abstract: A unique combination of four colorants (C′M′Y′K′) of a given printer that is equivalent to an externally defined four colorant combination (CMYK) by having the same color values (e.g., L*a*b* values). A fourth colorant, e.g., black, (K) of the externally defined four colorant combination is mapped to an equivalent fourth colorant (K′) of the printer by matching optical density, reflectance, L* or similar color value. The L* value is found for various percentages of the fourth colorant of the printer by printing varying percentages of the fourth component and measuring its L*a*b* values and, assuming a* and b* are near zero, using the L* value. These values are inputted into an interpolation program. Then, patches of varying percentages of each one of the three color components of the printer (CMY) are printed out at varying percentages.

Abstract: A digital color printing method and system is described which automatically detects when a black object is commanded to be printed, and changes the composition of the black color depending on the presence or absence of non-black colorants in the background color at the position on the page at which the edge of the black object is commanded to be printed. A single-color black object which is commanded to be printed at a position in which there is a previously rendered color background which contains non-black colorants will automatically have the composition of its black color changed from single-color black to process black composed of black plus non-black colorants such as cyan, magenta, and yellow. Conversely, a process black object which is commanded to be printed at a position in which the background does not contain non-black colorants will automatically have the composition of the black changed from process black to single-color black.

Abstract: An image processing system for printing, in which a decrease in saturation in the entire image is prevented while maintaining reproducibility for an achromatic color (gray balance). The image processing system extracts an achromatic-color component from an image signal including C, M and Y signals, and performs color correction for the C, M and Y signals by subtracting the achromatic-color component from the C, M and Y signals. The system then generates a K signal based on the achromatic-color component, and adds the achromatic-color component to the C, M and Y signals subjected to the color correction.