Abstract: An image file representing at least a portion of a printed document is processed to highlight the differences between foreground material (e.g., text or other characters) from background. The method includes selecting a neighborhood of pixels, determining a weighted average of an attribute values (e.g., luminance) for each pixel, and modifying each pixel's value based on the weighted average. Graylevel scaling, error diffusion, and a bit level conversion are also performed each pixel ends up with either a first attribute value level (e.g., luminance of 0) or a second attribute value level (e.g., luminance of 255).

Abstract: What is disclosed is a novel system and method for color trapping on halftoned bi-level bitmaps. Color edges are detected and edge pixels that need to be trapped are identified. The number of pixels qualified as edge pixels eligible for color trapping can be up to a pre-determined number of pixels away from the color edge. Estimates for the continuous-tone values are obtained for the dominant colors on each side of the two-color edge. The contone value of the dominant color on the opposing side of the two-color edge is assigned to the qualified edge pixels. Qualified edge pixels are re-halftoned using their assigned contone value so that halftones for one color are extended beyond the edge into the other color. The re-halftoned edge pixels are combined with the original bitmap to produce a new bitmap for the image. The new bitmap is then provided to an image output device.

Abstract: The present invention aims to prevent a problem that an image on a document sheet is erased due to misdetection of a line-shaped noise. A copy machine 1 compares RGB values of a target pixel with averaged RGB values (Step S103). If only one of the RGB values has a difference that is greater than a prescribed value Ref2 (Step S103: YES), the copy machine 1 extracts the target pixel as a line-shaped noise pixel, and moves to a line-shaped noise correction (Step S108) while holding the address of the target pixel in a line-shaped noise address storing area 49b. If two of the RGB values have differences (Step S103: NO, Step S104: YES) and a difference between these two of the RGB values is no greater than a prescribed value Ref3 (Step S105: YES), the copy machine 1 extracts the target pixel as a line-shaped noise pixel, and moves to the line-shaped noise correction (Step S108) while holding the address of the target pixel in the line-shaped noise address storing area 49b.

Abstract: What is disclosed is a novel system and method for minimizing dot visibility in color marking devices capable of dot-on-dot printing. The present method achieves minimum dot visibility for a given dispersed-dot screen by performing a CMYK to CMYKRGB conversion which uses less visible dots as much as possible before more visible dots are introduced. The output color dot coverages are calculated sequentially to minimize the coverage of more visible dots in a decreasing order of brightness. Resulting images have noticeably reduced halftone graininess, particularly in the mid to darker tone areas. The present method is also computationally efficient.

Abstract: An image processing apparatus includes (i) a repulsive force generating section for setting repulsive force values RVa and RVu of a quantized pixel according to an output pixel value of the quantized pixel, (ii) a repulsive force calculating section for calculating a repulsive force value RVC to be used in quantizing a quantization-target pixel by attenuating, according to a distance between the quantized pixel and the quantization-target pixel, the repulsive force values RVa and RVu set for the quantized pixel; and (iii) a threshold value correcting section for correcting a threshold value T used in quantizing the quantization-target pixel according to the repulsive force value RVC. This makes it possible to prevent an increase in the number of processing steps and amount of processing when an image is processed with an error diffusion method. At the same time, it is possible to prevent decrease in image uniformity and formation of a pattern unique to the error diffusion method.

Abstract: A tone dependent green-noise error diffusion method includes setting a first threshold and a second threshold, and determining a two-level value of a color level of an input image according to the first threshold and the second threshold; subtracting the two-level value from the color level value to generate an error value; performing an error diffusion on the error value to generate an error diffusion accumulation value; adjusting the color level according to the error diffusion accumulation value; performing a hysteresis filtering on the two-level value to generate an output dependent feedback value; and adjusting the color level according to the output dependent feedback value.

Abstract: A system and method for reducing the noise induced in a particular section or level of a signal bandwidth. The section is isolated from the rest of the signal data, by rescaling this data to produce a buffer section adjacent the section with little or no data in it. The signal is then transmitted to the output device where all data is the buffer section is considered to be the result of noise, and is mapped back to the predetermined level. The signal data is inversely rescaled to move data back into the buffer section. In this way, more of the data that was input at the predetermined level, will also be at the predetermined level afterwards, thereby correcting noise induced in that level by noise inducing transmission techniques such as JPEG compression.

Abstract: A calibration data creating device includes a reference measured density memory, a dither data memory, a corresponding set density determining unit, a calibration data creating unit, and a calibration data creating unit. The reference measured density memory stores measured densities of reference density patches that are formed by an image-forming unit based on the reference density patch data. The dither data memory stores dither data that has a plurality of dot locations, the dither data having a prescribed threshold at each dot location. The corresponding set density determining unit determines corresponding set densities for the plurality of the reference set densities.

Abstract: Aspects of the present invention comprise systems and methods for detecting and managing peripheral devices that perform outside a given performance envelope. In some aspects, one or more threshold values may be determined prior to or during implementation by heuristic or other methods. These threshold values may then be used to determine device performance. In some aspects, threshold values may relate to performance parameters comprising device failures, consumption levels, output quality and other parameters. In some aspects, multiple threshold values may be used to determine device performance. In an exemplary aspect, a sheet usage threshold, a tone usage threshold and a power usage threshold may be used to determine if a device is an outlying device. In some aspects, performance below an excellence threshold value may indicate that a device has excellent performance.

Abstract: An image forming system, image forming apparatus, and method of correcting image density are provided. The system includes a forming unit that forms an image; an acquisition unit that acquires factor information corresponding to a factor which is capable of causing variations in density of the image; a first determination unit that determines a number of marks in accordance with the factor information; a control unit that provides the forming unit with, as the image data, data pertaining to a pattern comprising a plurality of density marks which are different from each other in density and which are equal in number to the number of marks; a detection unit that detects a density of the image formed on the target by the forming unit in relation to the pattern; and a correction unit that corrects the density of the image in accordance with a result of the detection.

Abstract: In connection with the digitization of documents, a process and system wherein an automated quality control function operates to automatically determine the quality of an image according to predetermined characteristics and their associated values. According to this novel system and process, if an image fails to meet specified quality criteria it may be marked as such and that information as well as other information concerning the image will be made available during archival and thereafter including during a retrieval operation.

Abstract: The invention distinguishes not only character areas and halftone dot areas in an image, but also makes highly accurate decisions concerning characters present in halftone dot areas. A decision signal generating unit generates a decision signal having luminance as a main component from a signal indicating inputted image data, and supplies the decision signal to a character decision unit, a halftone dot decision unit, and a character-in-halftone dot decision unit. The character decision unit generates data indicating whether a pixel of interest is inside a character image area. The halftone dot decision unit generates data indicating whether a pixel of interest is inside a halftone dot area. The character-in-halftone dot decision unit generates data indicating whether there is a character image inside the halftone dot area. Based on these three signals, an attribute flag generating unit generates attribute data of the pixel of interest.

Abstract: What is disclosed is a system and method for improving vector halftoning in ink-jet printers capable of dot-on-dot printing. In one embodiment, n input Ci/Mi/Yi channel and a colorant Ki are received. If any of the Ci/Mi/Yi is greater than 100?Ki then that channel is clipped to 100?Ki. Next, a minimum total coverage area of a secondary color RGB dot required to achieve a remaining CMY coverage area is determined. If the minimum total coverage area is non-zero, then the following steps are performed. Each of a primary output Co/Mo/Yo is determined. Each of the primary outputs is then scaled by a ratio of the remaining primary color area over the total remaining toner coverage. The results are sorted and secondary color RoBoGo outputs are determined from the sorted results.

Abstract: A method of producing a printed output on a substrate is provided using a drop emitting device which is adapted to emit a plurality of ink quantities in response to a control signal.

Abstract: What is provided are a novel system, method, and computer program product for hierarchical (telescopic) color error diffusion which effectively controls the dot distribution for both primary and secondary dot formation which covers the class of error diffusion that follow telescopic dot firing constraint principles. In one example embodiment, an input CMYK ink coverage is received. The input CMYK ink coverage is transformed into a CMYKRGB domain using a CMYK to CMYKRGB conversion. A weighted error value can be added to each color component of the CMYKRGB domain. The color components of the CMYKRGB domain are hierarchically grouped into a plurality of subgroups based on relative dot visibility. More visible subgroups are half-toned earlier to achieve maximum uniform dot distribution. Dots of specific color channels within subgroups are fired based on thresholding and a set of decision rules provided herein.

Abstract: In an image output control system of the invention, an image processing device makes image data subjected to a preset series of image processing and supplies processed image data to an image output device to output a resulting processed image. The image processing device collects a predetermined number of plural pixels among a large number of pixels constituting the image to one pixel group, specifies number of dots to be created in the pixel group, and outputs dot number data representing the specified number of dots to be created in the pixel group to the image output device. The image output device stores multiple priority orders of pixels for dot formation in each pixel group. The image output device receives the output dot number data, selects one priority order among the stored multiple priority orders, determines position of each dot-on pixel in each pixel group, and actually creates a dot at the determined position of each dot-on pixel, so as to output a resulting image.

Abstract: In order to eliminate image deterioration based on the characteristics of an output device upon execution of edge emphasis processing, an image processing apparatus includes a setting unit which sets a print characteristic on the print medium, a region setting unit which sets a region, a brightness value derivation unit which derives brightness values, a first derivative derivation which derives first derivatives of the brightness values, an edge direction determination unit which determines an edge direction of brightness, an emphasis level determination unit which determines an emphasis level of a pixel value based on the first derivatives, and a replacement unit which calculates second derivatives of brightness values and replaces a pixel value of a pixel of interest based on the sign of the second derivative.

Abstract: A disclosed dither matrix is used in halftone processing for converting input image data having M input halftone levels into output image data having N (M>N>2) output halftone levels. In the halftone processing, a concentration type dither matrix is used as the dither matrix when an input halftone level is within a range of input halftone levels corresponding to an output halftone level that is lower than a predetermined threshold level T (N>T>1), and a dispersion type dither matrix is used as the dither matrix when the input halftone level is within a range of input halftone levels corresponding to an output halftone level that is equal to or higher than the predetermined threshold level T.

Abstract: There is provided a dither pattern capable of reducing deterioration in image quality caused due to beading by suppressing the occurrence of grains in printing images using a plurality of color inks. If among threshold dots, for which repulsive force potentials are totalized, a threshold dot Do has the largest total, a change in repulsive force potential is obtained between before and after the movement of dot Do. The threshold dot Do is moved to a dot with the smallest total of repulsive force potentials between before and after its movement. By repeating this process, the total energy of all the three planes can be reduced, achieving a dot distribution, in which the number of low frequency components is reduced and the dots are appropriately dispersed, for superposed dither patterns.

Abstract: A method for halftoning an image using an error diffusion process generates an upper threshold level and a lower threshold level and selects a region number parameter. A pixel from the input image is selected and compared to the upper and lower threshold levels. A first pixel value is output when the input pixel value is below the lower threshold level. The first pixel value is output when the input pixel value is below the upper threshold level and above the lower threshold level and a value of the input pixel divided by the region number parameter, modulo 2, equals zero. A second pixel value, the first pixel value being different from the second pixel value, is output when the input pixel value is below the upper threshold level and above the lower threshold level and a value of the input pixel divided by the region number parameter, modulo 2, is greater than zero. The second pixel value is output when the input pixel value is above the upper threshold level.

Abstract: In an image processor, a data corrector corrects input image data, a determining unit determines an output tone value of a target pixel from the corrected image data and threshold, and a calculator calculates a difference between the output tone value and the corrected image data as an error value. The threshold is set in such manner that a rate of change of the mean error of the error values with respect to a change in the input tone value is within a predetermined range.

Abstract: This invention provides a method for generating a dither matrix includes: setting an evaluation function for calculating an evaluation value of the dither matrix; providing a dither matrix as an initial state which stores in respective elements each of a plurality of threshold values for deciding presence or absence of dot formation for each pixel according to an input tone value; fixing an element for storing a threshold value in an increasing order from a smaller threshold value while transposing at least one of the plurality of threshold values stored in a part of the elements and a threshold value stored in another part of the elements; and outputting a dither matrix in which elements for storing are fixed with regard to at least part of the plurality of threshold values.

Abstract: An image forming device includes a table for storing link service function information that indicates a function necessary for providing the link service among functions installed in a computer for each link service, a computer status check portion for checking a function of the computer that is available at present, a provision appropriateness determination portion for determining whether or not each link service can be provided at present in accordance with the link service function information and the check result, and a screen display process portion for displaying identification information of the link service that is determined to be able to be provided.

Abstract: The image processing method for performing halftoning of a digital image constituted by an array of pixels having grayscale values which correspond to a content of the digital image, the method comprises the steps of: grouping the pixels constituting the digital image into a first group comprising pixels in pixel positions from which a quantization error generated through quantization is diffused to a peripheral pixel, and a second group comprising pixels in pixel positions from which the quantization error generated through quantization is not diffused to a peripheral pixel; performing a first quantization process on the pixels belonging to the first group using a threshold matrix; determining the quantization error generated during the first quantization process; diffusing the quantization error obtained in the quantization error determining step to at least one non-quantized pixel belonging to the second group which is adjacent to the pixel subjected to the first quantization process; and performing a seco

Abstract: An image is generated by performing area coverage modulation to express a halftone color according to a gross area of dots displayed in a pixel of the image. The image is generated in such a manner that the halftone color is expressed with a selected one of dither patterns corresponding to respective predetermined densities, each of the densities being determined by the gross area of dots calculated in view of shapes of the dots.

Abstract: A controller reads out image data of an area frame that a user has drawn on an original and accurately extracts the area frame by removing noise from the read-out image data to divide image data of an area outside the area frame and image data of an area inside the area frame into separate stencils, according to a separation program. It is therefore possible to execute a separation process desired by the user without increasing costs and man-hours and with easy operations not making the user feel troublesome.

Abstract: When copying an object that has faded markings of color fadable toner and is printed with the color fadable toner, a threshold value changing key is displayed on a liquid crystal display of an operation panel to be pressed down. A main CPU sets a threshold value 1a and a threshold value 2a in an image processing unit upon detecting the threshold value changing key displayed on the liquid crystal display of the operation panel via a touch panel. The image processing unit eliminates a background image by using the set threshold value 1a and threshold value 2a, thereby providing dark printing with an excellent image.

Abstract: A method of dynamically adjusting and predicting a segmentation threshold is provided. The method comprises calculating a threshold factor, calculating an actual average image pixel intensity for an entire image frame, and predicting a future average image pixel intensity for future time t, wherein the predicted future average image pixel intensity is based on past actual average image pixel intensities. The method also comprises combining the predicted future average image pixel intensity with the threshold factor to provide an adaptive threshold that adapts to changes in pixel intensity due to movement of an object in the image frame.

Abstract: A plurality of items of color-component data representing an image are input and a plurality of items of output color-component data representing an image to be reproduced by a printer are decided and output. In the case of an image in a specific area in which an entered image is represented by at least two items of color-component data, any one item of color-component data is decided upon as output color-component data.

Abstract: A print apparatus which receives image data from a digital camera, PC card, or PC to print an image on a storage medium outputs print data based on image data from the PC to a printer engine via a USB hub, and prints an image. The apparatus has a DSP which receives compressed image data from the digital camera or PC card, decodes the received data, and parallelly executes, for the decoded image data, at least color space conversion processing, size change processing, and color conversion processing. The apparatus generates print data on the basis of the image data processed by the DSP, outputs the generated print data to the printer engine, and prints an image.

Abstract: A method, and a system employing the method, of enhancing an intensity of an image of a multi-page or multi-portion document is disclosed. The method includes determining a first background parameter from a first section of a scanned page and stretching data corresponding to the scanned page based on the first background parameter. The method also includes determining a second background parameter from data of a second section of the scanned page and stretching data corresponding to another scanned page based on the second background parameter.

Abstract: The image processing method comprises: a recording failure position determination step of determining a recording failure position on an image corresponding to a malfunctioning recording element; a basic threshold value matrix storage step of storing a basic threshold value matrix set with threshold values used for halftoning of converting multiple-value input image data into dot data of a number of tonal graduations smaller than that of the multiple-value input image data by quantizing the multiple-value input image data; a sub-matrix storage step of storing a plurality of sub-matrices in association with recording failure positions in the basic threshold value matrix, each of the sub-matrices being set with threshold values which are substituted for the threshold values in a partial region of the basic threshold value matrix, the partial region including a pixel position corresponding to the recording failure position and having a width of a prescribed number of pixels; a replacement region determination st

Abstract: An image-processing apparatus for quantizing multi-level (M-level) image data into N-level values, where M>N>1, using a multi-level error-diffusion process or a minimum-average multi-level error method is disclosed. The image-processing apparatus includes: means for outputting correction data; means for setting a quantization-threshold value; means for comparing the correction data and the quantization-threshold value so as to output N-level image data; and means for calculating an error generated with generating the N-level image data.

Abstract: An input scanner, such as used in a digital copier, accepts original documents on sheets of any number of possible sizes within a single job. The video output of the scanner is applied to an algorithm to determine the length, along a process direction, of useful image data on each sheet. From such a determination, a size of output copy sheets can be automatically selected, or the image can be automatically changed in size in subsequent processing. A prescan of the original documents is not required.

Abstract: An image forming device includes a quantization unit which quantizes each pixel of an M-level gradation input image into one of N levels (M>N?2) through an error diffusion process. An operation unit performs a predetermined operation according to a position of a target pixel to a gradation value of the target pixel before quantization when the gradation value of the target pixel is equal to a specific concentration.

Abstract: A system and method remove at least one color from a color image in a chrominance-luminance color space. The processing method includes generating screen values for machine independent color space image pixels, comparing the screen values for the pixels with pixel values for one component of the machine independent color space, and generating a dropout pixel for each pixel having a screen value that is less than the pixel value for the one component of the machine independent color space. The screen value for a pixel may be compared to the pixel value for the luminance component to determine whether to generate a dropout pixel or not.

Abstract: In a threshold matrix generation part 3 implemented by a computer, a tint image in a specified gray level is generated from temporary lighting order set in a matrix area, and a smoothing operation is performed on the tint image, to generate a grayscale evaluation image. The lighting order is modified by changing ordinal numbers in the lighting order of respective positions included in specified areas in the matrix area which correspond to areas around boundaries of halftone dot areas in the tint image on the basis of values of corresponding pixels in the evaluation image.

Abstract: A process for the modeling of dots in the generation of a threshold matrix for a screen for the production of a screen form for the printing of image data. The dots are described by model points built up from computed points with an assigned density value. For modeling of ink-jet printing, in the area of overlap of neighboring model points the density values of the computed points are added to form a sum density, the sum density is limited to a maximum possible blackening, and the percentages of the sum density which exceed the maximum possible blackening are distributed to the neighboring computed points. For the modeling of offset printing, in the area of overlap of neighboring model points the maximum of the density values of the computed points is determined as the resulting density and with a filter operation a dilatation of the model points is effected.

Abstract: A method for generating a threshold value matrix is used in the frequency-modulated half-toning of the image data to be reproduced. A threshold value matrix for a basic screen is generated in that low-pass filters of different width are applied to the bit patterns generated and the threshold value distribution is changed on the basis of the filtered results. Furthermore, the bit patterns generated are examined for specific part patterns and the threshold value distribution is changed in such a way that undesired part patterns no longer occur and, instead, desired part patterns, preferably rounded forms, are contained in the bit patterns generated. By use of a combination of scaling and/or rotation and/or mirroring of the threshold value matrix of the basic screen, threshold value matrices are generated for the printing inks.

Abstract: A method and system for performing error diffusion are disclosed. An ordered set of pixels, including a pixel intensity value for each pixel, is received. Each pixel intensity value includes a value within a range from a low value to a high value, inclusive. An initial error value is also received. Based on the pixel intensity values and the initial error value, a pixel value for each pixel and an updated error value are computed substantially simultaneously with each other.

Abstract: An image processing apparatus including an image reading mechanism, a display, a memory, an image processing mechanism, an image creating mechanism, and a controller. The image processing mechanism performs first and second corrections using the plurality of stepped values. The image creating mechanism creates first and second subtractive images based on a first corrected image corrected by the first correction and a second corrected image corrected by the second correction. The controller controls the display to display the input image, the first corrected image, the final corrected image, the first subtractive image, and the second subtractive image in a screen image. A method of image processing and a computer readable data storing medium storing a program for image processing are also described.

Abstract: When the input value becomes close to the medium dot relative density value (Den_M), the large dot threshold value (Thre_L) and medium dot threshold value (Thre_M) become close to each other. It is possible to prevent output values from being converged to the particular medium-dot output value. When the input value becomes close to the small dot relative density value (Den_S), the medium dot threshold value (Thre_M) and the small dot relative density value (Den_S) become close to each other. It is possible to prevent output values from being converged to the particular small-dot output value.

Abstract: A halftone-image processing device divides all the pixels for input image data into a plurality of 2×2 recording matrices and performs a process on each of the recording matrices. The halftone-image processing device stores a threshold table indicative of a one-to-one correspondence between a plurality of threshold values and a plurality of output dot combinations of large, medium, and small output dots. The halftone-image processing device calculates the sum of density values for all the pixels in a recording matrix, compares the sum of density values to the threshold values in the threshold table, and determines an output dot combination for the subject recording matrix based on the compared results.

Abstract: A method for processing image data that employs a stamp field that contains data representing a distance metric for use with a variety of error diffusion operations. The distance metric possesses distance-order preservation permitting the distance from a previous dot to be determined by incrementing the distance metric, without knowing precisely where the previous dot was printed.

Abstract: Artifacts of error diffusion halftoning are reduced by selecting a halftone threshold for a current pixel on the basis of an accumulated halftone error for the pixel and its neighbors.

Abstract: A controller reads out image data of an area frame that a user has drawn on an original and accurately extracts the area frame by removing noise from the read-out image data to divide image data of an area outside the area frame and image data of an area inside the area frame into separate stencils, according to a separation program. It is therefore possible to execute a separation process desired by the user without increasing costs and man-hours and with easy operations not making the user feel troublesome.

Abstract: A method for processing image data that employs a stamp field that contains data representing a distance metric for use with a variety of error diffusion operations. The distance metric possesses distance-order preservation permitting the distance from a previous dot to be determined by incrementing the distance metric, without knowing precisely where the previous dot was printed.

Abstract: It is an object of this invention to provide a ternary or higher-order quantization method which avoids close gathering of pixels at a first output level. First and second threshold values Lth1 and Lth2 for ternarization and output values 0 (blank), 1, and 2 as converted output values are set to have a relationship of output value of 0 (blank)<first threshold value Lth1<second threshold value Lth2<output value of 1<output value of 2. This prevents a quantization error from becoming 0 when an input pixel value is an intermediate value, and prevents continuous outputting of only pixels having the output value of 1. When this image is printed, small ink dots corresponding to the output value of 1 are not easily continuously printed. This improves the image quality.

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 input image is transformed to produce an output image. First pixels occurring at edges within the input image are detected. Second pixels that are part of text within the input image are also detected. The first pixels and the second pixels are combined to produce the output image.