Abstract: Aspects of the invention provide a color matching profile generating device that, in an apparatus having an input device and an output device, performs a color matching for the input device and the output device and reproduces favorable colors without depending on color characteristics of the devices. The color matching profile generating device can use an input device profile and an output device profile, in addition to a color conversion profile which defines color conversion characteristics in an absolute color space and generates a color matching profile for the input device and the output device. Since the color conversion profile defines the color conversion characteristics in the absolute color space, color conversion can be performed to image data obtained from the input device without depending on characteristics of the input device.

Abstract: A color processing method of an image forming device, and an apparatus using the same. In the image forming device, which prints data in a plurality of colors, the color processing method may include storing a plurality of color tables, each color table containing a reference factor used with color processing of image data of an original document, selecting one of the plurality of color tables, processing a color of the image data of the original document with reference to the selected color table, and converting and outputting the color-processed image data of the original document into a data format readable by the image forming device. Accordingly, a user can change the color representation of the printed image according to a predetermined mode.

Abstract: In one embodiment, a print system includes an anticipated ambient lighting selector to allow selection of an anticipated ambient lighting. A rendering module is configured to map a print job into raster data configured to reduce color cast in gray output when displayed under the anticipated ambient lighting.

Abstract: A method and device for accelerating a color conversion process that converts input image data corresponding to a first color space to output image data corresponding to an output color space. A temporary cache stores color information in an array, and performs a conversion calculation for each individual color combination. If a pixel corresponds to a new color combination, the pixel information is stored in a new index of the array. If the pixel repeats a previously processed color, the pixel information is stored in the same index of the array as the previously processed pixel. A color conversion calculation is performed after all pixels within a block of pixels are mapped to the temporary array.

Abstract: A test pattern printed by a printer is assessed—without colorimetric equipment—to provide data used in recalibrating the printer. The assessment may be made by an unskilled operator, and can include discerning whether a particular pattern is visible in the printed test pattern, or whether a feature in the test pattern is relatively wider or narrower. From such assessment, needed changes to the printer's calibration data are inferred and implemented. A variety of other printer calibration techniques are disclosed. The technology is illustrated in the context of dye sublimation printers, and is particularly useful in optimizing printing of digitally-watermarked graphics.

Abstract: A method for characterizing an image where a number of test areas of predefined shape and size are located on the image. The color or the texture of the image over each of the test areas is quantified. The image can be characterized by statistical descriptions of the frequency distribution of color or texture of the test areas.

Abstract: Disclosed is an image color management system and method for controlling an image output device. The method for controlling the image output device comprises generating an image output device profile LUT (look-up-table) characterizing the color profile of the image output device for a plurality of drift states associated with the image output device; generating a set of basis vectors representing the LUT; storing the set of basis vectors in an image output device controller; and generating an image output device active profile associated with a current drift state of the image output device to convert image color data for display or printing by the image output device, wherein the image output device active profile is generated from the set of basis vectors.

Abstract: A plurality of color conversion profiles are prepared for each of plural types of color conversion profiles. One profile is selected for each of the color conversion profile types according to the printing mode used when printing, and color conversion is performed by sequentially using the selected color conversion profiles, without combining these selected color conversion profiles.

Abstract: A method for processing an image. The method includes receiving an image having image values and described in a first color space and determining the image color space from a received image. Image values in the first color space are associated with values in a second color space so as to generate associated image values. Values in the second color space are converted to a third color space for display, wherein the third color space differs from the second color space by including additive primary colors.

Abstract: A primary color dot gain correction unit corrects the spectral reflectance of each of a plurality of color agents on the basis of the dot quantity set for each color agent. An initial estimated value calculator estimates a mixed color by the KM theory using spectral reflectance data corrected by the primary color dot gain correction unit. An ink overlap correction coefficient storage unit stores correction coefficients, which are determined on the basis of errors between the actually measured values of spectral reflectance data of color patches obtained using the plurality of color agents, and estimated values estimated by the initial estimated value calculator based on the dot quantities of the respective color agents on the color patches.

Abstract: A technique is provided that can realize improvement in memory access efficiency and reduction in the processing volume in interpolation calculation with respect to color conversion processing using a two- or more-dimensional lookup table. In a color conversion apparatus, in accordance with an n-dimensional lookup table that stores a color conversion value corresponding to each of division points dividing each color component axis in a first color space realized by n types (n is an integer of one or larger) of color components, into plural sections, and thereby dividing the first color space into plural areas, a color value of a point belonging to the first color space is converted to a color value of a point belonging to a second color space.

Abstract: A technique that can contribute to improvement of processing efficiency in performing image processing employing an SIMD command is provided. A color conversion apparatus that converts, on the basis of a three-dimensional look up table that stores color conversion values associated with respective plural lattice points dividing a first color space represented by three kinds of color components into plural cubic lattices, a color value of a point belonging to the first color space into a color value of a point belonging to a second color space.

Abstract: A fast, low-memory-requiring, adaptive algorithm for determining and correcting for page background color generally involves quantizing the color component values of the pixels of the scanned page, dividing the scanned color space into a set of bins, and assigning each color in the scanned representation to a particular one of the bins to obtain a summary of the distribution of colors. Statistical information that is indicative color component characteristics of colors in a particular bin is collected for each bin. Using this information, each bin that constitutes a color peak is identified, and a region of influence for each color peak with respect to bins that are not color peaks is determined. The color peak corresponding to the background color of the document is then determined, according to predetermined rules that take into consideration the statistical information and region of influence determination. Three 1-D look-up tables are then constructed to adjust scanned colors.

Abstract: An image forming system according to an aspect of the present invention comprises a component data acquiring unit that acquires a component from color lookup table data; a verifying unit that determines whether or not the component of the color lookup table data acquired by the component data acquiring unit has been generated according to a predetermined generating rule; and a download data generating unit that downloads the color lookup table data and generates download data to be used in image forming processing from the color lookup table data after the verifying unit determines that the component has been generated according to the generating rule.

Abstract: A method of reconstructing the content of an ink color decomposition table is available as a method calibrating second- and higher-order colors. However, it is difficult to reconstruct the ink color decomposition table while maintaining a limitation upon the overall amount of ink allowed by the printing paper. Accordingly, a printer is made to form a color patch that corresponds to the signal value of a color to be calibrated, the signal value is calibrated based upon the measured color value of the color patch formed and a target value that corresponds to the signal value of the color to be calibrated, and multidimensional table data for calibration is created based upon the measured color value of the color patch formed.

Abstract: A method of selecting inks for use in imaging with an imaging apparatus includes determining a maximum usage of a diluted ink for use in conjunction with a saturated ink based on visual perception characteristics relating to a combination of the diluted ink and the saturated ink; generating an initial colorant space based on the maximum usage of the diluted ink, the initial colorant space expressing an initial usage of the diluted ink and an initial usage of the saturated ink at each point in the initial colorant space; optimizing the initial usage of the diluted ink and the initial usage of the saturated ink in the initial colorant space to generate a final usage of the diluted ink and a final usage of the saturated ink in a final colorant space; and generating a color conversion lookup table based on the final colorant space.

Abstract: A feature amount converting unit performs a color conversion of an input data. A history storage unit stores history information about a measurement of a color chart including conversion values of measured values of the color chart. An arithmetic unit compares the history information with new input information for measurement of the color chart, and determines the number of color patches based on a result of the comparison. A profile updating unit updates a printer profile based on a determined color chart data, and stores the printer profile in the history storage unit.

Abstract: A table representing a color gamut for a device for use in a color management system where colors are represented in a color appearance space comprises data representing a collection of hue slices through a boundary surface of the color gamut. The collection of hue slices comprises entries for vertex point hue slices obtained at each vertex point on the boundary surface of the color gamut, and entries obtained for additional hue slices between adjoining vertex point hue slices, where a number of the additional hue slices is determined such that there is no more than a specified angular difference between each hue slice. Each hue slice is represented by a hue value and a collection of hue slice points each containing a lightness value and a chroma value.

Abstract: This presently described embodiment deals with this problem by dynamically constructing color management device profiles that are optimized for accurate reproduction of a particular document. This apparatus utilizes three components. Device characterization data describes the relationship between device drive values (e.g., CMYK in the case of a 4 color printer) and the resulting color (spectral, CIELab, CIEXYZ or similar). Critical document colors are the critical colors in a document that is to be output on the device. The colors will generally be described by their CIELab, CIEXYZ or similar coordinates, but may also include color tolerances and frequency of occurrence values. Device modeling algorithms are mathematical procedures that allow the construction of device-to-color and color-to-device models in a way that different accuracy weightings can be applied in different regions of color space.

Abstract: An image processing method which changes a color image into a gray image, the image processing method including determining a plurality of representative colors, assigning gray values to the representative colors so that range variations between the gray values within a predetermined range are less than a predetermined value, and assigning a gray value to an arbitrary color of the color image according to a degree of similarity between the arbitrary color and the representative colors.

Abstract: A method and system are provided for processing digital multi-colour images for the reproduction thereof on a colour printing and/or copying system. Particularly, the printing and/or copying system is capable of complementary forming registered composite multi-colour images of coloured marking particles. This means that the separation images of coloured marking particles are formed contiguous to each other rather than in a superimposed relationship. The digital multi-colour images are processed such that during reproduction thereof any adverse effects on image quality caused by register errors in a predetermined direction are eliminated or at least limited. To accomplish this, a particular halftoning technique is used wherein with gradually increasing input density value of the image pixels, a linear growth pattern is generated in the predetermined direction by alternately adding image dots to both sides.

Abstract: In an apparatus for performing printing using a color ink-jet head having a plurality of ink-discharge-port strings corresponding to ink materials having different color tones, a high-quality image having excellent gradation can be recorded, while reducing the cost of the apparatus and increasing the data processing speed by reducing the capacity of a memory for storing dot arrangement patterns.

Abstract: If only a specific color and its nearby colors of image data are adjusted, density discontinuation occurs in the image as a whole. If masking is performed to avoid this problem, the adjustment range cannot be bounded, so the processing time increases. On an adjustment parameter designating unit, a user designates, as parameters, a reference color, the adjusted value of the reference color, and an adjustment region in a color space. A coordinate transformer transforms the coordinates of image data as an element of a color correction table, on the basis of a transformation matrix for transformation to an object color space. This transformation matrix is formed on the basis of the parameters by a transformation matrix calculator. If a region determinator determines that the image data is in the adjustment region, an adjusted value calculator calculates an adjusted value on the basis of the parameters.

Abstract: The technique of the invention joins a preset number of adjacent pixels into a unit and collectively converts input image data of each unit into dot data. Here the image data is expressed by tone values of respective pixels constituting an image, and the dot data represents dot on-off state. The technique stores dot on-off state determined with regard to at least part of pixels included in a processed unit, which has been subjected to the data conversion, in such a manner that a pixel position in the processed unit is identifiable. The procedure of the data conversion by units specifies a target pixel, in which a dot on-off state is to be determined, in a unit, detects a dot creation status with regard to an object pixel that is located at a specific position relative to the target pixel, and determines the dot on-off state in the target pixel based on the detection result.

Abstract: An application program may support multiple color spaces, such as Cyan Magenta Yellow blacK (CMYK) and Red Green Blue (RGB). Many computer operating systems have graphics drawing engines that only support RGB color space. For supporting non-RGB color spaces, the application program can use a color mapping table that defines a relationship between two color spaces such as CMYK and RGB. By generating unique RGB identifiers that can be passed through a graphics drawing engine and by using escape functions of a page description language, an application program can modify a printer file written in a page description language such that a non-RGB color space such as CMYK can be supported for publishing an electronic document.

Abstract: A drawing instruction processor refers to a bit map line table that shows whether the bit arrays in the row unit are the same in the order of concentrations. The drawing instruction processor decides whether dither patterns to be used for the adjacent specified drawing ranges are the same, by referring to the BLT, and links the drawing ranges to which the same pattern can be applied. Based on this, the drawing processor carries out a batch writing using a dither pattern prepared in advance into the specified range in the page memory. The dither pattern to be used for the drawing is prepared by linking a plurality of the same basic patterns to have a length corresponding to the length of the word length. As a result of such an arrangement, it is possible to achieve a high-speed processing.

Abstract: A method for multi-level halftoning an input digital image to form an output digital image which includes a multi-level error diffusion halftoning process incorporating periodic dither signals whose amplitudes are adjusted as a function of the error-diffusion texture characteristics.

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

Abstract: A controller for a four-drum printer eliminates a need for an expensive inter-drum delay memory, which has been conventionally used, to print an RGB image and allows a multifunction machine, printer, and the like to be provided at low cost. An image ring interface reads an image data containing the same tile, which is stored in a tile pattern in a RAM, four times with a delay corresponding to a delay (10 lines of tiles) of image formation between image forming sections, and sequentially transfers the image data to four image output interfaces.

Abstract: A picture image input method includes inputting a picture image of an object as a picture image signal. A histogram of a frequency with respect to brightness information of the picture image signal is created. A first brightness is created, which is a maximum brightness value within a region not greater than a first frequency value on a low brightness side of a brightness value which is lower by the a preset amount than the maximum brightness value within the histogram. A brightness group on a low brightness side of the first brightness side in the histogram is detected. A substantially maximum brightness value in the brightness group is set as a highlight point of the object. A gradation conversion table is created, which converts gradations of the picture image signal on the basis of the highlight point.

Abstract: A color output device is generally driven by at least three independent control signals for control of its response. A desired response in device independent color space is normally obtained by employing a cascade consisting of a characterization transform and calibration transform. The calibration transform transforms input control variables into output control variables that are directly used to drive the device. Input control variables can be transformed into intermediate control variables, which can be then mapped to output control variables utilizing a two-dimensional transformation. The two-dimensional calibration architecture provides improved control functionality and flexibility.

Abstract: The present invention provides an image processing method and an image processing apparatus for properly enabling a compressed image included in a page layout to be drawn in colors. A print server detects a compressed image in an EPS (JPEG) format or the like, sets a CMS according to the color plate being processed, and converts values of C, M, Y, and K. For example, when a process on the C color plate is performed, the converting process is performed by using a CMS 40C for the C color plate so that the value of “c” in the compressed image becomes a value of K (KC value). In such a manner, the values of K (KC, KM, KY, and KK) output from CMSs 40C, 40M, 40Y, and 40K are converted into values of C, M, Y, and K.

Abstract: What is disclosed is a method for compensating for printer characteristics having a tone reproduction curve which is either too rough to be fitted by interpolation or which does not have a simple parametric function. The method comprising first placing a first set of control points on the tone reproduction curve such that each point is representative of the behavior of the curve in the vicinity of that point and fitting a first smoothed curve to the first set of control points. A subset of points belonging to the set of first control points along the first smoothed curve is moved, thereby indicating a desired change in that region of the curve of the original function. A second set of control points is generated from the set of moved first control points and the remaining unmoved first control points and a second smoothed curve is then fitted to the second set of control points. A differential function between the first and second fitted curves is then determined.

Abstract: Methods and apparatus are disclosed for modifying the rendered output of a marking engine for a print job in progress. A marking engine commences printing print data for a print job. A parameter of a printed page of the print job is measured while the marking engine prints the print job. The measured parameter is compared to a reference, and the print data are modified before the print job completes, such that all subsequent portions of the print job are rendered with modified print data.

Abstract: An image processing device for processing an input image so as to reproduce a halftone, includes: a matrix setting section for setting a threshold matrix having a plurality of elements arranged in M columns×N rows, at least two threshold values being stored in each of the elements; an element specifying section for specifying a corresponding element of the threshold matrix in accordance with a position of a pixel in the input image; and a multilevel signal generating section for fetching the threshold values from the specified element and for generating a multilevel signal by transforming an input pixel value to one of multiple levels in accordance with the fetched threshold values; wherein the multilevel signal generating section outputs a constant value Doutmin as the multilevel signal when a first condition that the input pixel value is smaller than or not larger than a minimum value of the threshold values, is satisfied; the multilevel signal generating section outputs a constant value Doutmax when a seco

Abstract: The present invention implements a CMYK to CMYK pre-transform in front of at least one printer to be clustered where the transform is designed to ensure that the printers addressed through the pre-transform have substantially identical output color for substantially identical input CMYK values. As one form of implementation a method is disclosed to build CMY to CMY 3D-LUTs and 1D-LUT for K using sensors in the field. Making use of a system LUT—CMY to CMY 3D-LUT and a K to K 1D-LUT—improves consistency and provides a coherent control strategy and a means to provide standardized input CMY and K values in a clustered environment so that single or multiple vendor DFEs see substantially identical CMYK values.

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

Abstract: The technique of the present invention allocates a coordinate point of target image data on a color space to multiple lattice points in a color conversion table and reads data stored at the multiple lattice points. This arrangement ensures high-speed color conversion of the target image data. The procedure selects multiple lattice points and allocates a coordinate point of one target image data to the selected multiple lattice points. The procedure then specifies color-converted image data corresponding to the target image data, based on data read from the multiple lattice points. A first application allocates the target image data to the coordinate points of the multiple lattice points arbitrarily selected in the vicinity of the target image data. A second application allocates N-dimensional target image data to the coordinate points of multiple but not greater than N lattice points.

Abstract: A method and system for color calibration or color output device spectrophotoically measures at test target including a preselected test color value. A multi-dimensional LUT of the device is generated representative of the color information including the at least one preselected color. Producing a second image width device including the at least one preselected color located at a plurality of spatial locations in the second image. A second sensor measures the second image and a plurality of spatial locations having the preselected color for generating reflectance information for the preselected color at the plurality of spatial locations. An error is determined between the measured color of the one preselected color and the reflectance information at the other pixel locations. A multi-dimensional LUT is adjusted to minimize spatial uniformity errors at the other pixel locations, thus calibrating device color output spatially.

Abstract: Provided are a method, system, and article of manufacture for mapping an input color value in an input color space to an output color value in an output color space. A lookup table in a computer readable medium maps an input value having color components in an input color space to an output color value in an output color space. The lookup table has n number of possible values for a fixed color component in the input color space and less than n number of possible values for t color components in the input color space. An input value in the input color space is received and a determination is made of surrounding input values in the lookup table surrounding the input value in a t dimensional space, wherein each surrounding input value has a same value for the fixed color component. A determination is made from the lookup table of surrounding output values in the output color space to which the determined surrounding input values map.

Abstract: For M (magenta) and C (cyan), in a case of generating, e.g., ternary data of C0 to C2 and M0 to M2 respectively by using a look-up table on the basis of an error diffusion method, in a highlight portion of input M and C data (to which errors Ce and Me have been added respectively), a conversion space of correlating these data is used, while in a high-density portion, a conversion space equivalent to ordinary error diffusion is used. Thus, in a case of converting multivalued color image data into data of a lesser number of bits than the number of bits of color components constituting the multivalued color image data, it is possible to maintain excellent tonality on the entire image, and particularly to control graininess by preventing image quality deterioration in the highlight area.

Abstract: A data converting circuit to receive an input data and convert the input data into an output data is disclosed. An output data group corresponding to the value of the input data is stored beforehand in an output data table. A multiplexer receives the input data and in accordance with the input data, selectively outputs one data out of the output data group stored in the output data table. A specific digit output circuit receives the input data and in accordance with the result of comparing the input data with the boundary information stored in advance, outputs a specific digit output data included in the output data but not output by the multiplexer.

Abstract: Systems in accordance with the presently claimed invention use input data to create an output pulse that is a fraction of the width of a pulse of a pixel clock. The fraction of the width of a pulse of the pixel clock can be used to create a fraction of a pixel. Justification data may also be used to justify the fraction of the pixel. The presently claimed invention maintains a static pixel justification lookup table that can be used to determine the justification for each pixel.

Abstract: Disclosed is an apparatus and method for color-editing capable of simply carrying out color-editing spectral values, such as spectral reflectance, spectral transmittance, spectral radiance and spectral radiant intensity. When color-editing a spectral value of spectral image, the spectral color is transformed into a low-dimensional color space easy for the human to handle in an HLS space transforming section and color-editing and color-correction are carried out in the low-dimensional color space in on HLS color-editing section thereby generating a proper spectral value from a transformed low-dimensional color in a spectral-space inverse-transforming section. Also, a spectral color editing section receives a spectral editing instruction signal and transforms a wavelength width of a spectral color peak to a narrow one, thereby improving saturation.

Abstract: An image processing apparatus creates a pixel value histogram of an objective image, and approximates a predetermined range of the created histogram by a bended line formed from two straight lines. Then the apparatus extracts a pixel value at a boundary between a predetermined region and another region of the objective image in accordance with the approximation.

Abstract: Methods are described for calibrating a virtual printer including a plurality of color marking engines. The methods include printing a test pattern on one of the marking engines, the test pattern including a plurality of test patches, each test patch including corresponding expected colorimetric values, reading the test pattern with a colorimeter to determine measured colorimetric values associated with each of the test patches, and creating a lookup table that maps the measured colorimetric values to the expected colorimetric values.

Abstract: A method and apparatus for printing a multivalue image in a binary-form output pattern. The printing apparatus employs a binary-form dither matrix pattern which is composed of a greater number of pixels, so that moiré patterns and other artifacts are minimized in printouts. The method includes: providing the binary-form dither matrix pattern for use in obtaining the binary-form output pattern; expanding the multivalue image in a memory area; and forming a binary image of output dot elements in accordance with the binary-form output pattern. The binary-form dither matrix pattern has a rectangular pattern in which a plurality of pattern elements that are numbered to be successively turned on are arranged in matrix. The turning-on sequence is set in such a way that plural groups of prospective output dot elements, which groups are substantially identical in shape, grow successively from a plurality of local points associated with the respective groups.

Abstract: A printing system which prints an image with a print head having a plurality of nozzles capable of forming a dot includes a section acquiring first image data including pixel data constituting the image, which shows a pixel density value of M (M?3), a section storing nozzle information of each nozzle, a section determining whether to use the nozzle corresponding to each pixel data, a section modifying the density value of the pixel data set as non-use to a lower density, a section increment-correcting the modification-prior density value, a section distributing the increment-corrected density value to the density value of a predetermined pixel adjacent the pixel of the increment-corrected pixel data, a section generating print data to prescribe dot formation information of the nozzles corresponding to the image data after the distribution of the density value, and a section printing the image based on the print data.

Abstract: A method for reducing image noise in a digital image including establishing image data of image pixel values; specifying a local virtual surface patch; fitting the local virtual surface patch to the image data; using the local virtual surface patch to estimate a palliative value of at least one pixel in the region of the local virtual surface patch; replacing an original pixel value with the palliative value.

Abstract: A multi-tone image processing method and apparatus in which mutually dissimilar tone levels are realized by changing the additive condition of recording energy by means of different recording positions, even when the number of recording operations within a specific range is identical. For example, in an electrophotographic apparatus, when the number of irradiation by a light spot within a specific range remains constant as the irradiation position is changed in the specific range, there is a change in the additive condition of the optical energy within said specific range. Thus, the area rendered visible within the aforesaid specific range also changes, thereby changing the tone level.