Abstract: Color data, originally corresponding to different colors, are converted to the same density when gray-scale conversion is performed, and no boundary is distinguished. When performing the gray-scale conversion, color data of an object adjacent to an object to be processed is referred to. As a result of such reference, even if it is detected that the object to be processed and the object adjacent to the object to be processed have different colors, but are converted to the same density by the gray-scale conversion, the gray-scale conversion is performed in such a manner that the boundary between the objects can be identified.

Abstract: The color determination circuit 308 detects hue of the color image information, and the controller 205 decides a color component to be separated (separation color) in accordance with the detected hue. Output color by the printer 204 is set in correspondence with the separation color. The two-color-separating circuit 303 separates the color image information into image information on at least two color components in accordance with the decided separation colors. The separated image information on the each color is transmitted to the printer 204 via printer density correction circuits 304 and 305, and a buffer 306. Thereby it is possible to provide an image processing apparatus capable of setting and changing the separation color and the output color by automatic operation or by simple manual operation, thus the expression of the image forming can be improved.

Abstract: A color image reading apparatus includes a color separation unit to separate a color of an image of an object into more than three visible color wavelength components in a visible wavelength range and an image sensing unit to read the image of the object whose color is separated by the color separation unit and outputting image signals of the respective colors. The apparatus also has a color calculation circuit to calculate image data of not less than three colors from the image signals corresponding to the colors separated by said color separation unit.

Abstract: A small-gamut colorant set is a new system and mechanism for reproducing monochrome images on a wide range of color printing devices with an unprecedented combination of flexibility and quality. It is fundamentally unlike, and yet in certain ways similar to, both existing colorant systems for printing color images and existing colorant systems for printing monochrome images. It combines many advantages from both of these families of traditional colorant systems into a kind of system that is superior in many ways for printing monochrome images. It uses a set of at least three tinted gray colorants to create a color space within which a small amount of chroma adjustment and the full range of hue adjustment is possible. These three tinted grays may be accompanied by a black colorant, and/or other shades of gray, or a second set of three tinted grays, depending on the opportunities presented by the nature of the printing device.

Abstract: A method is disclosed for reducing halo print defects occurring in printed/copied color images. The method includes detecting a boundary between a first image object and a second image object within a color separation of the color document, and modifying the video values of a plurality of pixels within the color separation so that the video values slope toward the boundary, the plurality of pixels being located within a transition zone adjacent the boundary. In the case where toner black is used, the video values of a plurality of pixels within a transition zone of a toner black color separation are modified so that the video values ramp or slope down toward the boundary, and the video values of a plurality of pixels within transition zones of a cyan color separation, a magenta color separation, and a yellow color separation are modified so that the video values ramp or slope up toward the boundary. In effect, the process increasingly replaces toner black with process black (i.e.

Abstract: A color image forming device and method prevent occurrence of pile height moires specific to electrophotographic images in low-frequency areas and conventional moires in a digital screen set of four colors. In the color image forming device, by at least one of a halftone generating part and scanning signal forming unit in an image processing unit, differences among screen angles of three dot patterns corresponding to cyan, magenta and black toner images are in the range about 25 to 40 degrees, preferably 30 degrees; the screen angle of a first dot pattern corresponding to a yellow toner image is made equal to that of a second dot pattern corresponding to the toner image of one of cyan, magenta and black; and the screen of the first dot pattern is brought about 150 to 210 degrees, preferably about 180 degrees out of phase with the screen of the second dot pattern.

Abstract: A color image reading apparatus includes a color separation unit to separate a color of an image of an object into more than three visible color wavelength components in a visible wavelength range and an image sensing unit to read the image of the object whose color is separated by the color separation unit and outputting image signals of the respective colors. The apparatus also has a color calculation circuit to calculate image data of not less than three colors from the image signals corresponding to the colors separated by said color separation unit.

Abstract: A buffer memory has a plurality of blocks which are virtually broken up into a matrix pattern. An image processing apparatus has a memory controller for writing R, G, and B image data in the buffer memory in units of lines and in a predetermined color order, and reading out the R, G, and B image data written in the buffer memory. The memory controller switches operation for writing the R, G, and B image data in the blocks that belong to corresponding rows, and operation for writing the R, G, and B image data in the blocks that belong to corresponding columns in units of lines, and reads out old image data from a region of the buffer memory in which new image data are expected to be overwritten before the new image data are overwritten by the write operation.

Abstract: An image processor in which an under color process is performed according to a color region to which input color image data belongs. The under color process generates a plurality of color component signals including a black component signal including a black component signal, with the color region being defined by hue. Therefore, even if input color image data includes color components other than an under color component, tonality (i.e., linearity between an input color value and an output color value) is compensated for.

Abstract: After light transmitted through platen glass is incident on a lens and focused, the light is transmitted through a parallel flat plate and imaged in a CCD image sensor. The resolving power of the CCD image sensor is 600 dpi in this case and one pixel is 8 &mgr;m. A parallel flat plate is provided with a function for displacing all rays incident on the plate in parallel. The quantity of parallel displacement differs depending upon each wavelength. Therefore, lateral chromatic aberration can be reduced to the extent that it is ignorable (approximately {fraction (1/10)} of pixel size) by making reflected light outgoing from the lens and having lateral chromatic aberration incident on the parallel flat plate.

Abstract: The invention involves selecting a path through a multi-dimensional hyper-cube from a base vertex to an opposite corner or vertex of the hyper-cube. The path is selected by ranking the fractional components of the point or value to be interpolated. An N-dimensional interpolation is performed according to this sequence. During an interpolation a base vertex for an input color value is determined. The output value for the base vertex is accumulated. The fractional values of the input color value are sorted and ranked according to magnitude to produce an interpolation sequence. The interpolations are performed for each axis of the N-dimensions by selecting an axis for interpolation based on the order, performing an interpolation corresponding to the selected axis producing an interpolation result, and accumulating the interpolation result.

Abstract: A system for recording and reproducing a color image of a scene includes an image recording apparatus including a body portion for containing components of the apparatus and for housing a roll of black and white silver halide emulsion film. The body portion includes a focal lens for focusing scene illumination to expose the film with the scene image. A color filter disposed in the body portion filters the scene illumination. The filter includes a color filter array having a plurality of adjacent pixel arrays, whereby the scene illumination is pixelated on the black and white film for each array as units of luminance and chrominance information.

Abstract: An image reading apparatus and method are provided which precisely correct shading due to dispersion of the spectral sensitivity characteristic of a reading area of a reading device. Second correction values for correcting, for each of R, G and B, shading due to partial dispersion of spectral characteristics of color separation filters are respectively set and stored for each film type and for each of a plurality of blocks forming an image, on the basis of results of reading a film for correction value setting. Then, from the stored second correction values, correction values corresponding to a type of a film which is an object of reading are retrieved to derive correction values for each pixel by interpolation. The derived correction values for each pixel are added to first correction values for correcting shading due to irregularity in the amount of light or the like.

Abstract: An image processor includes an input device that inputs image data representing a target image, and a color gamut mapping device that performs a color gamut mapping process. The image processor also includes a color reproduction process device that performs a color reproduction process, and a judgment device that judges whether a monochromatic mode for forming an image on a recording medium is set. A controller controls the color gamut mapping device and the color reproduction device, with the controller inhibiting the color gamut mapping device from performing a color mapping process on the input image data when a judgment is made that the monochromatic color mode is set.

Abstract: A color reproduction region of an image formation apparatus is to be effectively used and characteristic in lightness, hue and chroma is to be smoothed. In case of creating tables for separating color into color of coloring agent available in the image formation apparatus, a maximum line in the color reproduction region of the image formation apparatus is defined, internal lines in the color reproduction region of the image formation apparatus are defined and the tables are created by performing interpolation processing on the basis of the maximum line and the internal lines.

Abstract: An image pickup apparatus is provided which can obtain a high image quality by using a camera with a conventional field read type DSP. The image pickup apparatus has an image pickup element having a plurality of color filters disposed in a predetermined layout at respective pixel positions, a calculating and processing unit for performing calculation and processing by using two sets of adjacent pixel data in the vertical direction, at each line of image data generated by the image pickup element, and a luminance signal generating unit for generating a luminance signal by using an output of the calculating and processing unit.

Abstract: A method for producing multicolor printing, by using printing plates provided digitally with images and/or print, represents an efficient solution for multi-color printing, in particular in a large format. Printing plates, which had been used in a printing press, are removed from the printing form cylinders, are sent to a device for neutralization, and are neutralized. The neutralized printing plates are fixed at correct registration in an exposure and development unit where they are exposed and developed. The printing plates provided with new images are again applied to the printing form cylinder.

Abstract: A color quantization method based on an HMMD color space and a multimedia searching method using the same in extracting color features for searching multimedia, to enable searching of multimedia data which has been quantized on different levels. A quantization method is optimized to be proper for various quantization levels so as to increase search performance in an HMMD color space. And the interoperability between color features quantized into different quantization levels is provided so as to search multimedia generated from different application programs and in which a quantization rule is defined so as to maintain high search performance. Preferably, the present invention provides a color quantization method for various levels, thereby enabling to achieve high search performance on maintaining interoperability. The present invention provides a multimedia search method enabling to measure the similarity between features quantized into different levels.

Abstract: A method and apparatus are provided for canceling crosstalk noise arising on signal lines output from an image sensor. More specifically, the crosstalk noise is canceled by a current mirror that is coupled to the signal line. The current mirror adjusts the voltage level on the signal line by drawing a current therefrom that is proportional to the amount and polarity of the crosstalk noise. The amount of crosstalk noise is determined by an amount of coupling within an A/D converter coupled to the signal lines. The current mirrors can further adjust the voltage on the signal line by drawing a current therefrom that is proportional to crosstalk arising due to a voltage level on another signal line. Such a current mirror allows pixel data to be conveyed to the A/D converter, via the signal lines, without imparting aberrations due to crosstalk noise.

Abstract: An image processor converts an input signal into first and second color components and a component. A plurality of output device dependent color-component data is read from a look-up table on the basis of the first and second color components and the brightness component. Interpolation processing is performed on the basis of the read plurality of color component data to generate output device dependent color-component data corresponding to the input signal.

Abstract: In image formation, one of a plurality of print modes having different allowable print-material discharge amounts is selected. Color image data inputted by an image generator is converted by a LOG converter into CMY data. An UCR & black-generation processor performs density control on the CMY data by each color component, and performs under-color removal and black-generation processing on the density-controlled image data. The UCR & black-generation processor controls a total amount value of the output image data, based on the allowable print-material discharge amount of the selected print mode. The obtained image data is &ggr; corrected and binarized, then outputted to a printer.

Abstract: This invention relates to an image processing method and apparatus and particularly solves problems of image degradation in multi generation copying (copying, using a previous copy output as an original). A generation copy mode is provided in addition to the normal copy mode.

Abstract: The invention relates to an apparatus for producing a photographic picture on a copy material, whereby an exposure arrangement with a projection optics is provided for the production of the photographic picture which includes a mirror matrix with individually movable mirrors, whereby the exposure arrangement includes a wide-band light source, for example a halogen light source, whereby a filter arrangement is positioned in the light beam between the light source and the mirror matrix in order to filter out or let pass specific spectral regions or specific amounts of light.

Abstract: The invention intends to match the image writing start positions for different color components, even in case of the rotation speed of the photosensitive member etc. fluctuates by the variation in the load or by the backlash of the driving gears. For attaining this object, the invention is featured by a configuration of detecting and retaining the phase difference between the ITOP signal and the BD signal at a predetermined timing, also detecting the phase difference between the ITOP signal and the BD signal for each formation of the color component image, comparing the phase difference detected at the predetermined timing with that detected for each formation of the color component image, and controlling the timing of starting the image formation by changing, by an image writing tart timing control circuit, the number of BD signal to be counted after the generation of ITOP signal and before the start of image formation.

Abstract: A color image pickup apparatus includes a photo-to-electric conversion section subjected to progressive scanning. A first delay circuit defers an output signal of the photo-to-electric conversion section. A first adder combines the output signal of the photo-to-electric conversion section and an output signal of the first delay circuit. A second delay circuit defers the output signal of the first delay circuit. A second adder combines the output signal of the photo-to-electric conversion section and an output signal of the second delay circuit. A third delay circuit defers an output signal of the first adder. A first subtracter implements subtraction between the output signal of the first adder and an output signal of the third delay circuit. A fourth delay circuit defers an output signal of the second adder. A second subtracter implements subtraction between the output signal of the second adder and an output signal of the fourth delay circuit.

Abstract: The present invention relates to a method for coding a signal which describes a picture as a function of three tristimulus values (X, Y, Z), to produce a signal which describes the picture as a function of n independent display primaries (R, G, B, D1, . . . , Dn−3), with n>3. In this method, for each color to be represented, drive signals for the display primaries (R, G, B, D1, . . . , Dn−3) are calculated via a comparison of the location of that color with respect to a straight line in the chromaticity diagram. A number of the drive signals are mutually exclusive. The invention also relates to a display system comprising n display primaries, where n>3.

Abstract: A color image printing apparatus includes a controller having a plurality of under color tables in which an under color concentration value for black developer, to be used as a substitute for color developer, corresponding to a common concentration value included in each of the three primary colors of yellow, magenta and cyan constituting a pixel display color of the original image, is set differently for a non-toner saving mode than for a toner saving mode, for outputting an under color concentration value for black determined, corresponding to the common concentration value and net concentration data for yellow, magenta and cyan which are obtained by deducting the under color concentration value from concentration data of each pixel display color of the original image, from the under color table corresponding to the toner consumption, an engine for printing a color image on a recording medium with the concentration of developer per color corresponding to the net concentration data for yellow, magenta and cy

Abstract: A process for converting black-and-white color separation information contained in PostScript software to color separation information which can drive a color output device to print at least two different colors, which process comprises determining the position of commands in the black-and-white software which define the color output for the information on one color separation, and changing the command to indicate that a color other than black is to be produced.

Abstract: A system providing a direct construction or calculation of color gamuts offering advantages over earlier techniques with respect to speed of calculations and the accuracy of the gamut description. The starting point for the gamut construction process is the calculation of a forward model from color patch measurement data which establishes an analytical relationship between ink and color in a given direction: ink to color. The model is used to obtain a regular sampling of profile connection space color values with corresponding inkings on the surface of the ink space polygon. These points are ordered by angle and by expected ink behavior to define the connectivity of the points of the gamut boundary.

Abstract: According to the improved method of transforming device-taken color/density data to calorimetric values, color/density data obtained by imaging with a device are transformed to calorimetric values by the steps of correcting device data with correction data to construct setting data, the device data being obtained by imaging with the device in the actual scene a color chart having patches formed thereon in a plurality of colors/densities, and the correction data being obtained by imaging an achromatic chart having achromatic patches formed thereon with the device under the same conditions as the color chart; measuring the color chart with an instrument to provide reference data; setting color transforming conditions from the reference data and the setting data for transforming the color/density data to calorimetric values; and transforming the device-taken color/density data to calorimetric values using the color transforming conditions.

Abstract: A method for downscaling an image from a sensor color filter array space having the step of determining an initial image size. The method also has steps of determining a set of stride lengths, locating a single color pixel of interest, and generating a full color pixel. An apparatus having a processor and a memory coupled to the processor for performing the above steps is also disclosed.

Abstract: Disclosed is a color image processing system making it easy to carry out color management while taking account of the use environment and tastes of a user of any device.

Abstract: An image processing system comprises a first input unit for inputting an image signal, a second input unit for inputting a character or code signal, a binarizing unit for binarizing the image signal, including a unit for gray level processing the image signal, a discrimination unit for discriminating the presence or absence of a gray level in the image signal, and an output unit for outputting the image signal when the discrimination unit discriminates the absence of the gray level or the character or code signal as a digital image signal without processing the signal by the gray level processing unit.

Abstract: A recalibration transformation is derived for a color image reproduction system having an input device and an output device by obtaining a medium conveying a selected color within a current gamut of the output device represented by first values in a first color space, scanning the medium with the input device to obtain second values representing the selected color in a second color space, applying a calibration transformation to map the second values to third values in the first color space, deriving an error transformation that maps from the first values to the third values, and deriving the recalibration transformation from an inverse of the error transformation that maps from the third values to the first values.

Abstract: A multi-color image forming apparatus and method to form a color image by overlapping multiple gradation pattern images formed for each of the recording colors based on the input color image information, wherein the screen angles of the unit gradation patterns of the multiple gradation pattern images are set such that they are separated from one another by 20 degrees or more, and in which the first unit gradation pattern is formed using a line pattern in which the colored dot patterns are made to extend in the direction corresponding to a first screen angle and the second unit gradation pattern is formed using a line pattern in which the colored dot patterns are made to extend in the direction corresponding to a second screen angle which is different from the first screen angle by 90 degrees.

Abstract: Device independent color signals in color coordinates of the calorimetric system are computed using the color signals Ci, Mi, Yi, Ki in first CMYK coordinates. A maximum quantity of black maxKi of the color signals Ci, Mi, Yi, Ki is computed by using the color signals Ci, Mi, Yi, Ki and the device independent color signals. A black ratio g of the color signals Ci, Mi, Yi, Ki is computed using the maximum black quantity maxKi and the color signal Ki. A maximum quantity of black that can be obtained without changing the device independent color signals is computed using the device independent color signals. The color signal Ko in second CMYK coordinates is determined by the maximum black quantity and the black ratio, and the color signals Co, Mo, Yo, Ko in the CMYK coordinates are determined by using the device independent color signals and the color signal Ko.

Abstract: A color image recorded on an original is photoelectrically read by use of an area sensor on which an image of the color image is formed through a zoom lens. A color component image signal representing information on a predetermined color component is continuously obtained from an image formed on the area sensor and reproduced as a visible image on a CRT, while two-dimensionally moving the original and zooming the zoom lens. A plurality of color image signals are obtained from an image formed on the area sensor when the original and the zoom lens are in a position where only a desired part of the color image is displayed on the CRT, and reproduced as a visible image.

Abstract: An image forming apparatus discriminates a color of an inputted color image for each pixel and generates a first color component and a second color component. The apparatus compares values of the first and the second color components, and selects and outputs the color component having a larger value. Meanwhile a color component which is not selected is diffused to neighboring pixels. When pixels neighboring a pixel of interest in a predetermined area are filled with one color component, the other color component is selected and outputted regardless of the values of the first and second color components.

Abstract: A color conversion device includes a region judging section for judging which region of a three-dimensional color space contains an input value, and/or a representative points-dispersed axis selecting section for selecting a representative points-dispersed axis which is nearest to said input value. Additionally, the color conversion device includes a representative points selecting section for selecting representative points in the vicinity of the input value among representative points discretely arranged along (or within) the selected representative points dispersed axis; a look-up table (LUT) which stores coordinates of representative points and color correction data; and a linear interpolation section for performing color conversion by weighting based on the selected representative points.

Abstract: An image processor performs image processing depending upon a plurality of data types such as additive color mixing type colors or substractive color mixing type colors. Other data types may be processed such as when extra colors are used other than yellow ink, magenta ink, cyan ink and black ink, in order to enhance image quality in an ink jet recorder, or in the event an ink color is arbitrarily changed or one or more types of ink colors are increased or decreased.

Abstract: A system for recording and reproducing a color image of a scene includes an image recording apparatus including a body portion for containing components of the apparatus and for housing a roll of black and white silver halide emulsion film. The body portion includes a focal lens for focusing scene illumination to expose the film with the scene image. A color filter disposed in the body portion filters the scene illumination. The filter includes a color filter array having a plurality of adjacent pixel arrays, whereby the scene illumination is pixelated on the black and white film for each array as units of luminance and chrominance information.

Abstract: A target-less calibration system for calibrating a scanner for a particular input medium without using a dedicated calibration target on that medium is disclosed. The system employs the (predetermined) spectral response of the scanner and representative spectral measurements of the input medium to achieve the calibration. The representative spectral measurements of the input medium are used to infer the set of feasible spectra for the medium. Corresponding to a given scanner signal output, another set representing the candidate spectra that could have resulted in the given scanner output are determined using the predetermined scanner spectral response. Combining the two requirements, a spectrum in the intersection of the thus determined sets of scanner candidate spectra and prenoted feasible media spectra provides an estimated spectrum of the input sample. Repeating the process over the range of scanner outputs provides a complete spectral calibration for the scanner for the given medium.

Abstract: A method is described for printing a colorant controlled neutral black object in a bitmap-based digital color printing system. The method is useful in systems where the black colorant is not sufficiently opaque to hide non-neutral combinations of non-black colorants mixed into the black color. Black colors in a color printing system can be composed either of black colorant only or of black plus non-black colorants such as cyan, magenta, and yellow. If the non-black colorants are not mixed in nearly equal quantities, they will add hue to the black color. A sufficiently opaque black colorant can hide this objectionable non-black hue. However, in cases where the black colorant is not opaque enough, it is important to use equal or nearly equal combinations of cyan, magenta, and yellow so that little net hue will be introduced into the black color. Equally important in some printing systems is the ability to control the amount of total colorant used in forming a process black color.

Abstract: Methods and apparatus for determining the allocation of a trap width to the spread of a pair of inks in printing. Allocation of the spread is based on both a solidity value that may be between zero and one and a lightness value. The technique may be applied to an arbitrary number of inks by considering each pair of inks separately.

Abstract: A vector error diffusion system for quantizing pixel value in color images, which initially determines whether any pixel should be white or colored, and subsequently determines whether the pixel should be a primary color, a secondary color or black.

Abstract: In data processing wherein image data are processed by dividing them into blocks, a chroma data W is obtained from the color difference data W.sub.R and W.sub.B, and the color difference data W.sub.R and W.sub.B are corrected according to an amplitude of the chroma data W. For example, if the chroma W is smaller than a prescribed threshold value, the color difference data W.sub.R and W.sub.B are set as zero. Then, the so-called block distortion can be prevented. The degree of the correction may depend on the amplitude of the chroma data W. On the other hand, DC coefficients of discrete cosine transform coefficients of adjacent blocks are compared with each other. When the DC coefficients are different from each other, block distortion occurs if they represent a same image. Then, if differences of DC coefficients of discrete cosine transform coefficients of adjacent blocks are small with each other, the DC coefficients are corrected to tend to have similar values.

Abstract: An image reading device for photographic printing comprising an optical lens mechanism, a monochrome CCD image device arranged at a focal position on an optical axis of the optical lens mechanism, a filter rotation plate having a plurality of color filters rotatably arranged on the optical axis, and a cut filter for blocking unnecessary light arranged on the optical axis, wherein a light quantity correction means for obtaining stepwise spectral characteristics is arranged on the optical axis. The reflected light due to the conventional ND coating and the influences of the boundary plane and the parallel degree between the cut filter and the color filter are disappeared, whereby the occurrence of flare, ghost and color divergence can be prevented.

Abstract: A method for color error diffusion using semi-vector quantization is proposed that simplifies error diffusion calculations. When three color separations are used, the two separations with the most visually perceptive color output are compared with one another to determine their output colors, while the third, least visually perceptive separation, is treated separately. A correction term may be applied to the third separation based on the color output of the first two separations to insure uniformity of ink coverage. This method yields results close to vector quantization and also minimizes fluctuation in the two most visually perceptive output colors. Of course, this method may be used with more than three color separations. For example, when four color separations are used, the least visually perceptive color is processed differently than the three other color separations.

Abstract: An image input and output system for scanning an image of a color original and processing data of the scanned image has a color line sensor for picking up the image of the original. The system also includes a memory for sequentially storing three types of data respectively representing the three primary colors and which are outputted from the color line sensor, in the order in which the data are outputted. An output control circuit calculates an address to read out the data stored in the memory such that a series of three data respectively representing the three primary colors and composing a first pixel partially overlaps with a series of three data respectively representing the three primary colors and composing a second pixel next to the first pixel, and for reading out, from the memory in accordance with the calculated address, a series of three data respectively representing the three primary colors to produce image data of the three primary colors for one pixel.

Abstract: In a three-line linear sensor, a first linear sensor (10) without electronic shutter structure and second and third linear sensors (20), (30) with electronic shutter structures (28), (38) being disposed in an axial symmetry fashion are combined and a line spacing (D1) between the first and second linear sensors (10), (20) can be reduced by an amount corresponding to the omitted electronic shutter structure. Also, since the second and third linear sensors (20), (30) are disposed in an axial symmetry fashion, a line spacing (D2) between the second and third linear sensors (20), (30) can be reduced and set to be substantially equal to the above-mentioned line spacing (D1).