Abstract: In a printing system constituted by a host computer and a printer, in an operating system of the host computer, a GDI module receives a drawing command from an application, and converts this drawing command into another drawing command which can be understood by a printer device driver. In the device driver, first, a preprocessor receivers the drawing command from the GDI module, and detects black areas contacting with color areas in figures or characters in a page on the basis of this received drawing command. Next, the preprocessor revises the drawing command so that the color of black areas contacting with color areas is changed from pure black to composite black. After this, the revised drawing command is sent to a rasterizer and a half toning portion sequentially, and converted into bit map data which can be understood by the printer. This bit map data is supplied to the printer through a print manager.

Abstract: Image processing apparatus and method perform a predetermined compression processing for an input original. A compression processing method or a receiver of compressed data is changed in accordance with a color/black-and-white status discrimination for the input original, or is set manually.

Abstract: To reduce rendering time for an image to be generated, an image to be generated, such as a page of a document, is divided into non-overlapping regions. Within each region, a determination is made whether all of the data contained therein is achromatic. If so, achromatic data is rendered for a single component of a multi-component color space. Pixel values are stored in one section of a frame buffer that relates to the single component. The other components of the color space use multiple references to the pixel data stored in this one section, rather than being separately rendered.

Abstract: An image processing apparatus includes a joining-portion processing section for combining partial images that have been read in a divided manner. Focused on partial document data predeterminately specified among a plurality of partial document data stored in an image memory, the joint-portion processing section performs a recognizing operation on the joints, a positioning operation and other operations beginning with the proximity of the specified partial document data. The partial images are then combined together to form one complete image. For example, in the case of copying an original document, which is of a size too large to be copied in one operation, on one sheet of paper in a reduced manner, it becomes possible to eliminate time consuming tasks such as trimming and pasting of the partial documents as well as calculating of the reduction rate.

Abstract: A dot judgment circuit judges whether there exists color information in dot-pattern-developed image data of pixels around a black pixel under attention. When not finding the existence of color information, the dot judgment circuit selects a head driver for driving a recording head for jetting a slow drying black pixel. When finding the existence of color information, the dot judgment circuit selects a head driver for a recording head for jetting a quick drying black ink or head drivers for recording heads for jetting quick drying Y, M and C inks.

Abstract: The present invention provides a color image forming apparatus for forming a color image using signals for coloring materials for yellow, magenta, cyan and black, comprises black amount detection means for detecting a signal corresponding to a black amount in each pixel, operation means for performing an operation on the detected signal in a scope of the pixel to be processed and its neighbor, and adjustment means for adjusting a coefficient for a filtering process on each color signal of a coloring material for the pixel to be processed based on a signal obtained by said operation.

Abstract: A data transfer device for transferring data in a color digital copier, color printer or similar image forming apparatus of the type using a plurality of different kinds of data. A sending unit assigns other data to a predetermined number of bits of multilevel data to thereby send a plurality of kinds of data over common data lines. A receiving unit receives and separates the plurality of kinds of data. The device reduces the number of signal lines required for data transfer when a plurality of different kinds of data are not transferred at the same time.

Abstract: There is provided a color image processing apparatus such as a color copier having the function to automatically discriminate whether each original is a black and white original or a color original. Such an apparatus has a discriminating circuit to discriminate the attribute of each original image, a memory to store the discrimination results by the discriminating circuit every original image in correspondence thereto, and a processor to process the relative original images in accordance with the discrimination results stored in the memory. The discrimination result is read out of the memory a plurality of times for the same original and the same original is processed a plurality of times by the processor on the basis of the discrimination result. The apparatus may also has an RDF to sequentially feed originals one by one to the image processing position by the processor.

Abstract: A color-image processing method is provided in which a two-color image can be formed in accordance with three color-image signals obtained by scanning a color original without having a color shear. A designated color is selected. A pixel is determined as the designated color by comparing the color-image signal with a sum of another color-image signal and a correction value. The pixel is determined as black when the color of the pixel has not been determined as the designated color. The pixel is determined as white by comparing intensity of the three color-image signal with predetermined threshold values. A color of a focus pixel is corrected by comparing linear patterns of colors of four consecutively arranged pixels including the focus pixel with a plurality of reference color patterns.

Abstract: An image processing apparatus reads color images, identifies the colors of an read color image, converts the color image into a monochrome image, synthesizes color recognition information on the monochrome image, and prints the resulting synthesized image as a monochrome image. As a result, even if a low-priced printer is employed, it is possible to provide a monochrome image permitting recognition of the colors of the color original, or quick identification of differences among the colors thereof. Moreover, this allows a user to specify a desired graphic pattern to be associated with a given color, and to obtain collation tables independently of the monochrome image, or to print the specified graphic pattern with any variable magnification power.

Abstract: In a printer which produces images as a function of the combination of cyan (C), magenta (M), yellow (Y) and black (K) colorants on an output color print, responsive to device independent colorimetric description of an image, there is provided a method of calibrating the response of the printer to an image described in terms of colorimetric values, including the steps of first, gray balancing or linearizing colorant signals; secondly, adding black to an ideal device dependent description of a color image in accordance with a predetermined black addition process, and thirdly, providing a color correction transformation process, where the color correction transformation is accomplished via a method of interpolating printer responses from a look-up table indexing colorimetric descriptions of measured real responses, which take into account subsequent black addition and signal linearization.

Abstract: A color separation processing method and circuit for reproducing a color image with four color components of yellow, magenta, cyan, and black. The method comprises the steps of: receiving target color signals representing a portion of the color image; determining an amount of a black color component of the portion of the color image so that the black color component of the portion is gradually changed from other neighbor portions of the color image; and determining amounts of yellow, magenta, and cyan components of the portion of the color image according to the amount of the black color component. The circuit realizes the method above.

Abstract: A lightness/chromaticity separation device converts three input color signals to {L*, a*, b*} signals. A chroma determination device determines a chroma signal C* based on the {a*, b*} signals. An UCR ratio calculation device calculates an UCR ratio .alpha. according to a C*-.alpha. function that is adjustable by changing parameters. A nonlinear conversion circuit determines output color signals of four colors including black based on the {L*, a*, b*} signals and the UCR ratio. The nonlinear conversion circuit includes a network-type combination of a plurality of analog nonlinear operation units.

Abstract: A color image forming apparatus including: a discriminating circuit for discriminating a character portion of an object color image; a color image forming device for forming a color image and able to change the image-forming resolution; and a control circuit for causing change of the resolution of the color image forming device in accordance with the discrimination result provided by the discriminating circuit.

Abstract: A method is provided for transmitting and receiving image data having plural pixel data. The method comprises the step of producing image control data for controlling the image data to be transmitted. The plural pixel data is represented by n color components, and pixel data represented by n+m color components is produced for sequential transmission on the basis of the pixel data represented by the n color components. The image control data are transmitted for a period of time when the pixel data represented by the n color components are not provided in the period of time when pixel represented by n+m color components are transmitted. An image process is executed for either the pixel data represented by the n color components or the pixel data represented by the n+m color components on the basis of the image control data.

Abstract: A document reproduction method and apparatus wherein a scanner scans a document to determine the color components of pixels forming the image information on the document. The color signals generated by the scanner are transformed into lightness space and each pixel is examined as part of a window that includes neighboring pixels. The examination involves a first determination of whether or not the neighboring pixels are white pixels, second and third determinations of whether or not the current pixel is a grey pixel and has high contrast, and a fourth determination of whether or not the window has text structure. In accordance with combination of these determinations, a decision is made to recast the pixel as a pixel to be reproduced with a black colorant to thereby minimize color fringing errors at the edge of text-like information.

Abstract: A digital color copying machine improves the quality of an image of black characters by reproducing them with only black toner and prevents the edges of each black character from being colored with a color. The machine includes a monochromatic signal generator for generating a monochromatic signal in response to inputted plural color signals and an edge emphasizer for emphasizing edge components of the color signals with a predetermined edge emphasis amount. Either a digitizer for digitizing the monochromatic signal and outputting a binary signal of the monochromatic signal or a pseudo digitizer for generating a pseudo binary signal by steepening the contrast of the monochromatic signal is provided. A first area detector, second area detector, and third area detector are respectively provided for detecting first through third image areas.

Abstract: A method for freely selectable substitution of the achromatic part in multi-color printing with the black ink on the basis of a spectrally photometrically scanned original, whereby supporting points in the color space are acquired in the spectrally photometric scanning of the original. Corresponding to a preselected degree, the achromatic part or the complementary color part of the colors of a printing color space constructed multi-color are replaced by the black ink. Supporting point data are photometrically acquired from a color scale specifically associated to a printing process. The printing color space is classified into a color model that is independent of a printing color (HSL Model, FIG. 1) and is displayed in this model. A two-dimensional, non-linear deepening field is formed with luminance values (FIG. 2) and a two-dimensional, non-linear desaturation field is formed with saturation values (FIG.

Abstract: A color image communication apparatus comprises first means for transmitting color image data through a digital circuit, and second means for transmitting data representing a color expression form of the color image data together with the color image data through the digital circuit.

Abstract: A color spatial filter for ink jet color printers, especially four color CYMK printers. The printer includes an enhanced print mode and associated logic circuitry which examines and corrects black pixel coloring to increase black picture quality and reduce intercolor bleeding. This is accomplished by examining a surrounding neighborhood of pixels around each pixel as they flow to a color swath print buffer and selecting a method of correcting the representation of each pixel, based on a set of predetermined rules, to produce black by choosing either K, a slow-drying high density ink, or CYM, a fast-drying ink having low intercolor bleeding to thereby control bleeding characteristics that provide the best copy quality images. A lookup table may be used for greater gradations of black representation. Alternatively, printing may be performed using a color printer having two black inks, each with different drying rates and picture qualities.

Abstract: When colorimetric values defined in a uniform color space are supplied, a plurality of sets of the amounts of print color materials of cyan, magenta, and yellow are obtained on the basis of the colorimetric values and a plurality of amounts of print color material of black. The ranges of printable color materials are obtained from the plurality of sets of the amounts of color materials of cyan, magenta, and yellow. The common range of the amounts of black material is obtained, which can be used to print each color materials, cyan, magenta, and yellow to reproduce a color. The amount of print color material of black in the range of the amounts of print color material of black is determined on the basis of a predetermined coefficient n. The amounts of print color materials of cyan, magenta, and yellow are determined on the basis of the determined amount of print color material of black and the colorimetric values.

Abstract: A color image reading system in which an input color image signal is converted into color data signals. The color data signals are indicative of a combination of data of reference stimuli represented by vertices of a triangle of which one side circumscribes a pure purple locus, and of which the remaining two sides circumscribes two points of a spectral locus of a color degree diagram, the two points representing substantially middle colors between a color represented by one vertex of the triangle at which the remaining two sides intersect and each of two colors represented by the remaining two sides of the triangle, respectively. The input color image signal is reproduced on a color image output device in response to the provision of the color data signals.

Abstract: An image processing apparatus includes a first judgment circuit for judging whether an input image is a monochrome image or a color image on the basis of an input image signal, and a second judgment circuit for judging whether a pixel represented by the input image signal is part of a character which is black. In an image processing method, a judgment is made as to whether an input image is a monochrome image or a color image on the basis of an input image signal, and a judgment is made as to whether a pixel represented by the input image signal is part of a character which is black.

Abstract: There is disclosed a color image forming apparatus provided with an input terminal for plural input color component signals and an output color component control signal, a processing circuit for processing the input color component signal to obtain plural output color component signals specific to the apparatus, and image forming means for forming each color component image according to the value of each output color component signal, in which the processing circuit is capable of controlling the calculation of output color component control signals according to the value of the output color component control signal.

Abstract: An image processing apparatus comprises: a receiving circuit to receive image signals of a plurality of colors, in which the image signals is received for every color by an amount of one image formation unit such as one picture plane; a detector to detect whether the image signals have properly been received by the receiving circuit or not; and an image forming device to form a color image on the basis of the image signals, wherein the image forming process by the image forming device is executed in accordance with the result of the detection by the detector. Even if a communication error was generated, a good color image can be reproduced.

Abstract: An image processing apparatus performs an edge correction process for image signals of respective pixels sequentially inputted, each image signal having a density level corresponding to a pixel. An edge amount detector of the image processing apparatus calculates a difference between a density level of an image signal of a specified pixel from among the image signals and a product of a predetermined value and the sum of the density levels of peripheral pixels located at a predetermined distance from the specified pixel, and outputs a detection signal having a level of an edge amount of the calculated difference, and an edge amount convertor converts the edge amount of the detection signal into a converted edge amount in a predetermined manner, and outputs a conversion signal having level of the converted edge amount.

Abstract: An image processing apparatus selects among two or more image input sources, and processes the image from a selected source for under color removal using an appropriate coefficient generated on the basis of the selection of the source.

Abstract: A method for defining a new value of K (black) corresponding with a change in CMY components. Original CMYK printing colors are provided. The original CMY printing colors are corrected to create new CMY printing colors. A value of a smallest one of the original CMY colors is sensed. A value of a smallest one of the new CMY colors is sensed. By use of each of these smallest values, the original K printing color value is modified to create a recalculated K printing color value. The recalculated black value corrects for distortion of original gray balance.

Abstract: A method for under-color removal in a color image forming apparatus comprises color conversion means for converting separated color signals into first color output signals, first black generation means for calculating first black output signal based on the maximum and minimum values of the first color output signals obtained by the color conversion means, means for performing under-color removal to calculate second color output signals by correcting the first color output signals converted by the color conversion means based on the first black output signal generated by the first black generation means and then removing under-color values from the first color output signals, black amount correction means for calculating second black output signal by correcting the first black output signal obtained by the first black production means, and chroma correction means for correcting the second color output signals obtained by the means for performing under-color removal based on the second black output signal obtai

Abstract: Three input color separation signals are converted to three color signals on a uniform color space. A black quantity to be used for full-black reproduction is determined as the maximum black quantity of an output black signal. Then, an actual black quantity of the output black signal is determined based on the maximum black quantity and a chroma signal obtained from the uniform color signals. Finally, color quantities of respective output color signals other than the output black signal are determined based on the uniform color signals and the actual black quantity thus determined.

Abstract: A method for improving the quality of full-color images is disclosed. An original image is divided into a plurality of pixels. A neutral intensity value is determined for each pixel. A desired black-color intensity value is determined from the neutral intensity value. A printer-producible black value is determined from the desired value. The printer-producible black-color intensity value is used to rescale the original color intensity values of the pixels. The rescaled color intensity values are used to generate output color intensity values. The output image comprising the output color intensity values and the printer-producible black-color intensity value may then be converted to a continuously varying or halftone output image and output to an image output apparatus.

Abstract: An apparatus for producing CMYK recording color component signal for each pixel in which RGB color component signal photoelectrically obtained from the original is converted into CMY color component signals. The converted CMY color component signals are separated into first, second and black color sub-component signals which are corrected respectively. Thereafter, the corrected first, second and black sub-component signals are added so as to form the recording color.

Abstract: A method and apparatus for color stimulus specification-correction, i.e. sensation-correction pickup for scanning of chromatic image originals, referred to in short as a multispectral scanner. A color image pickup system is provided, based on the multispectral principle, the plurality of I>>3 narrow-band spectral filters and one black filter being introduced into the optical beam path of the image scanner, and thus I narrow-band spectral separations of a color image original and of a white image original are registered and digitized. Spectral pixel samples individually calibrated for all pixels are formed with an electronic evaluation unit in pickup real time. These are either stored in I parallel image storage levels or are multiplied by specific coefficients from a table in pickup real time of the signals in three parallel channels and are accumulated in three parallel image storage levels.

Abstract: It is determined whether an object pixel in entered image data resides on (a) part of a black character or line, (b) not on part of a black character or line but in close proximity thereto, (c) neither part of nor in close proximity to a black character or line. When it is determined that (a) holds, the object pixel is recorded using dark black ink only. When it is determined that (b) holds, a pixel comprising various color components is recorded using ink whose density is lower that that of ink having a designated density. When it is determined that (c) holds, namely that the object pixel is remote from a black character or line, the object pixel is recorded using the ink of the designated density.

Abstract: This invention relates to a color image forming apparatus which is capable of forming a mono-color image based on the color image input data. The apparatus includes a circuit for determining the highest value of the image input data. This circuit is called the highest value image data outputting circuit. The highest input color data value is found by comparing the values of the image data for the three primary colors (yellow, magenta and cyan) and outputting the value for the color having the highest input value. The apparatus further includes a mono-color image forming portion which forms a mono-colored image based on the output of the highest value image data outputting circuit.

Abstract: An apparatus for image processing including a processor for executing a predetermined processing on black character areas in an image represented by an input color image signal, a first judging unit for judging a chromatic portion of the image, a second judging unit for judging an achromatic portion of the image in an area which has been judged to be a chromatic portion and a controller for controlling the processor according to the judgement made by the second judging unit.

Abstract: A dense black image is formed by printing the black ink in combination with at least one other ink without resulting in thick, blurred figure edges. A bitmap of binary information is provided for each of a plurality of color separations, each bitmap indicating desired locations of ink spots for a color separation. Spots are eroded on the boundaries of black areas in the black bitmap to form a modified black bitmap. The modified black bitmap is printed in at least one color other than black at the same time that the bitmaps for the color separations other than black are printed. The black bitmap is then printed in black over the printed modified black bitmap to yield a dense black image.