Abstract: In order to produce a high-quality output of an image which is a mixture of images having different characteristics, there is provided an image processing apparatus having an image memory storing an entered color image and a feature detector, arranged for detecting a feature signal from the entered color image and storing the feature signal in the image memory. The feature signal represents a feature of the entered color image. An outputter is arranged for reading an image signal of the entered color image and the feature signal thereof out of the image memory, and outputting the image and feature signals as a recording signal. Processors are arranged for respectively processing one of a number of color components, which represent color image information, in accordance with the recording signal. The detection and storage in the image memory of feature signals and the readout of the image signal and associated feature signal from the image memory are performed in parallel.

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: An image forming apparatus and a method of controlling the same in which input image data is divided into blocks and color chrominance data of each block is analyzed thereby perform a print job by automatically detecting whether an image should be print in color or pure black.

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 vector error diffusion (VED) method employable in cycles with respect to a hi-tonal color printing engine which prints bi-tonal color images in a device output color space. The method generally includes (a) acquiring input color-image data which is characterized with an input color space, (b) processing, with available pre-established VED accumulated error data, such input data to produce a VED-processed input color-image data stream, (c) from such VED-processed input color-image data stream, creating, without employing interpolation, a VED-processed output color-image data stream which is characterized by the mentioned device output color space, and which is suitable for delivery to and use by the mentioned printing engine, and (d) changing, as appropriate for the next cycle, the VED accumulated error data which will be employed in that next cycle as pre-established VED accumulated error data.

Abstract: An apparatus is capable of executing a facsimile communication using an Error Correction Mode (ECM) function based on a facsimile procedure with a communication partner connected via an Internet Protocol (IP) network. In response to receiving, from the communication partner via the network, a communication start request including information indicating a transport protocol for use in the communication, if the apparatus determines that the transport protocol for use in the communication does not have the error correction function, the apparatus sends to the communication partner a notification indicating that the apparatus is capable of executing the communication using the ECM function. Otherwise, if the apparatus determines that the transport protocol for use in the communication has the error correction function, the apparatus sends to the communication partner a notification indicating that the apparatus is incapable of executing the communication using the ECM function.

Abstract: The present invention relates to a method for producing halftone dots in the field of image hard copying, more particularly to a method for frequency-modulation screening using error diffusion based on dual-feedback. In the known frequency-modulation and amplitude-modulation screening technology, it is hard to output a halftone image with high quality using an output equipment with a low resolution (600 dpi) and the satisfactory effect of representing the gradations of the original image in detail and holding the smoothness of the original image can not be achieved. By using the dual-feedback technology based on a basic algorithm of the error distribution, the method in the present invention realizes the organic combination of the conventional frequency-modulation and amplitude-modulation screens and achieves the effect of mixed screening.

Abstract: This invention is a printing control method of generating print data to be supplied to a print unit which is capable of forming dots on a print medium by ejecting at least one type of colored ink containing a color material and a quality-enhancing ink for enhancing quality of a printed material. The printing control method comprises a color conversion step of converting pixel values into multiple gradation data of each ink, the pixel values representing color of each pixel of given image data, the multiple gradation data of each ink expressing the color of the pixel by using the colored ink and the quality-enhancing ink available in the print unit and a gradation-reduction step of generating at least part of colored dot data and transparent dot data by ordered dither method.

Abstract: An improved error-diffusion image processing system and the method thereof adopt the block reading mechanism to replace the row reading mechanism employed in the conventional error-diffusion image processing. This can greatly reduce the memory space required for image processing and increase the operational efficiency. The problem of gaps existing in the block reading mechanism is solved by adding a required error sum (BEsum) in a summed pixel range according to specific position conditions of each block.

Abstract: Provided are an apparatus and a method for driving a self-emission display panel. A sustain pulse (STP) controller calculates an automatic power control (APC) level of image data having an input grayscale and outputs a STP corresponding to the calculated APC level. A sub-field (SF) controller which applies a dithering method to each SF corresponding to the input grayscale to generate SF data for expressing the input grayscale so as to reduce the number of cells simultaneously emitting light in a SF. A sustain/scan driver generates sustain/scan pulses from the output STP to drive the self-emission display panel. An address electrode driver generates an address driving signal corresponding to the input grayscale from the generated SF data to drive the self-emission display panel.

Abstract: An image processing apparatus, a printing apparatus and an image processing method are provided which can perform quantization processing on image data at high speed based on an error diffusion method while at the same time avoiding degradations in a quality of printed images. When the error value represented by the error data is equal to or less than the reference value, at least a part of the data portion that can represent an error value in excess of the reference value is eliminated to compress the error data.

Abstract: A method of reconstructing an original image from a printed and scanned image includes determining a plurality of transformation parameters including a rotation a of the scanning grid relative to the printing grid and a plurality of translation parameters which give a position of a node on the printing grid in a coordinate system of the scanning grid, generating a system of non-linear equations which represent the printed and scanned image as a function of: (i) the original image, (ii) a print/scan resolution ratio, and (iii) the transformation parameters, computing coefficients for the system using the resolution ratio, the transformation parameters and the given print model, generating a linear approximation of the system of non-linear equations, solving the linear approximation for an approximation of the original image, and creating a reconstructed original image from the approximation of the original image.

Abstract: The generation of dot data of planes depending on a plurality of scannings and ink colors in an ink jet printing apparatus is performed based on the error diffusion processing for each plane without causing a problem of grain. Specifically, in a binarization processing, C divided data D8c/2 is subjected to an error diffusion processing to calculate binary (dot) data D2c1 for the first pass of C. Next, M divided data D8m/2 is compensated by being added with a term of Kc1m1(D8c/2-D2c1). Then, this compensated data [D8m/2+Kc1m1(D8c/2-D2c1)] is subjected to an error diffusion processing to calculate dot data D2m1 for the first pass of M. In this manner, the generation of the respective planes performs correction to reflect the results of the binarization processing of the respective previously processed planes to subject the compensated data to an error diffusion processing.

Abstract: Disclosed herein is a method and apparatus for moiré-free enhanced color halftone printing of color image separations for an arbitrary number of colorants. The method and apparatus utilizes a plurality of halftone screens, >4, to produce outputs that are moiré free and form hexagonal periodic rosettes. The relatively large number of screens can be used for enhanced printing applications, such as printing with high-fidelity colorants, light colorants, or special colorants, such as white, metallics and fluorescents.

Abstract: An image processing method that puts input image data represented by multi-value pixels into gradation representation of dots having binary data of plural minute pixels while performing error diffusion processing. The method includes a first step that when a dot is formed which corresponds to correction image data produced by adding correction data to multi-value image data of a multi-value target pixel, only in the case where the dot is to be formed so as to be adjacent to a dot formed for a proper adjacent multi-value pixel, forms the dot even if it has less than k (2 or greater integer) number of minute pixels. In other cases, the method forms only a dot having k number of minute pixels or more.

Abstract: The design of periodic screens for halftone patterns is based upon a series of constrained optimization problems. For each of a number of input levels, a pattern is found that minimizes a cost function. The cost function is a spatial-frequency weighted difference between an ideal, continuous-space pattern and a predicted reconstructed pattern. The frequency weighting is a parameterized trade-off between the preservation of periodic components and the introduction of non-harmonic components.

Abstract: An apparatus includes a gray converter to convert an inputted color image to be printed into a gray conversion image and to outputs the gray conversion image a difference calculator to calculate a at least one difference value between a at least one color channel image with respect to the color image and the gray conversion image; and a gray reviser to revise the gray conversion image based on the at least one difference value and to output a gray conversion image.

Abstract: An image processing method and an image processing apparatus converts a binary image into a grayscale image by increasing the size and information quantity of the binary image. The image processing method includes generating a plurality of lookup tables having multiple gray level values assigned to a predetermined pattern of the binary image such that the gray level is retrieved from the plurality of lookup tables depending on the context of the block being processed. The binary image may be converted into the grayscale image by applying the gray value of one of the plurality of lookup tables that corresponds to the context, such as the frequency components of the binary image. With this configuration, since the size and information quantity of an image can be reduced for transmission, it is possible to prevent deterioration of image quality when the image is restored, while also printing at a higher speed.

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: In a line by line image forming apparatus, line switching information which depends on scan line curve and an overlap data length to be read that overlaps across a plurality of lines before and after a switching position instructed by line switching information are set in a register. If switching to the line above or below is instructed by the line switching information, an address generating unit, when reading image data from an image memory, generates the read address and read data length of the image memory in accordance with the line switching information and the overlap data length, and reads image data corresponding to a current line and the line above or below the current line in accordance with the generated data.

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: An image processing device performs an error diffusion on multilevel input image data to generate multilevel output image data that has fewer levels than the multilevel input image data. The image processing device includes a plurality of setting devices, each of which sets a threshold value to be used at the error diffusion, a threshold value selecting device that randomly selects one of the plurality of setting devices with respect to each pixel to be processed and allows the selected setting device to set a threshold value with respect to the pixel to be processed when the image processing device performs the error diffusion, and a converting device that converts the pixel to be processed into multilevel output image data with fewer levels than multilevel input image data by the error diffusion, in accordance with the threshold value set by the setting device selected by the threshold value selecting device.

Abstract: A method for multi-toning an input digital image having input pixels with two or more color channels to form an output digital image having modified output levels. The method includes producing an error signal for each color channel, combining the error signals to produce a combined error signal, sorting the error signals to produce a set of sorted error signals, and determining modified output levels responsive to the set of sorted error signals and the combined error signal.

Abstract: The present invention relates to an image processing technique for improving dot dispersion in highlight areas and shadow areas in an error diffusion method. The image processing device of the invention has a plurality of types of error diffusion matrices with different diffusion ranges, and selects a matrix depending on the error that has occurred, which is then used to diffuse the error into peripheral pixels. Of the plurality of error diffusion matrices, the matrix having the widest diffusion range is a matrix that diffuses error with bias in the raster direction (specifically, a matrix having a directivity factor of 2.0 or higher).

Abstract: An image forming apparatus comprises: a reader to read image; an output part to output the image; an information giving part to give additional information to the image before the image is outputted by said output part; an output controller to make said output part output a plurality of test patterns for output level correction of additional information in different output levels; a data calculator for output level correction, to calculate data for output level correction of said additional information based on reading results drew by said reader from said outputted test patterns for output level correction of additional information; and an output level corrector to correct an output level of said additional information based on said calculated data for correction.

Abstract: An apparatus includes a first processing device to perform halftoning on a first set of values corresponding to a first set of pixels and a second processing device to perform halftoning on a second set of values corresponding to a second set of pixels, with ones of the first set of pixels located adjacent to the second set of pixels and with ones of the second set of pixels located adjacent to the first set of pixels. The apparatus further includes a bus arranged for transferring a third set of values, from the halftoning of ones of the first set of values corresponding to the ones of the first set of pixels, to the second processing device and for transferring a fourth set of values, from the halftoning of ones of second set of values corresponding to the ones of the second set of pixels, to the first processing device.

Abstract: An image processing apparatus which converts multiple-value image data of an image into a plurality of dot patterns to form the image on a recording medium includes: a corrected recording element signal table storage device which stores a plurality of corrected recording element signal tables respectively for the graduated tone numbers, each of the corrected recording element signals being one of corrected recording element signal numbers and determined so that banding caused by recording characteristics of the recording elements is corrected in accordance with a correlation between each of the recording elements and surrounding recording elements of said each of the recording elements; a one-dimensional dot pattern table storage device which stores a one-dimensional dot pattern table which specifies a one-dimensional dot pattern for each of the corrected recording element signal numbers; a corrected recording element signal conversion device which converts the multiple-value image data into a one-dimensional

Abstract: An image processing method coverts multiple-value image data of an image into a plurality of dot patterns to form the image on a recording medium, the multiple-value image data being constituted of a plurality of pixels each of which has a graduated tone value that is one of graduated tone numbers, the image being formed by means of: a recording head which has a plurality of recording elements arranged in a first direction, the recording elements forming dots on the recording medium to form the image in accordance with the dot patterns, each of the dot patterns representing an arrangement of the dots corresponding to the graduated tone value for each of the pixels; and a relative movement device which causes the recording head and the recording medium to move relative to each other in a second direction that is substantially perpendicular to the first direction.

Abstract: An improved color-image error diffusion process for use in conjunction with the operation of a multi-level, halftone, color-image output device. This process involves, first, performing output-device-dependent color error diffusion on color-image input data utilizing a halftone, output-device-dependent color palette containing output-device-dependent output color values. Thereafter, and with respect to the selection for pixel outputting of a pixel utilizing one of the output colors in the palette, and in relation to infeeding of that pixel to the output device for outputting, the process features applying a predetermined, dot-gain correction curve which corrects the infeed intensity value of the pixel in accordance with (a) the selected output color for the pixel, and (b) assessment of the pixel in terms of its association with a predetermined neighborhood pattern of adjacent pixels.

Abstract: A method for color cast removal in a scanned image in L*a*b* space includes generating a first color cast correction curve for mapping L* to a first color correction, ?a*, (or ?b*) wherein the first correction curve provides a desired a* shift in midtone regions and is modulated as a function of L* such that black and white points are unaffected; for each pixel n in the scanned image, passing L*n through the first color cast correction curve for obtaining a value of ?a*n; and adding the value of ?a*n to the scanned image's original a*n component. To ensure that the color corrected a* remains within gamut, a second correction curve for applying a clipping factor to the mapped ?a* may be generated with the a*n passing through the second correction curve for obtaining a clipping factor Cn; and modifying the a*n value by Cn(?a*n).

Abstract: An exchange infrastructure (XI) system provides for the receipt, storage and transmission of limited data to uniform user interfaces to provide an improved exchange of data thereacross. In operation with corresponding processing systems, there is a reduced amount of data received by the XI system as well as a reduced amount of data transmitted from the XI system to a recipient processing system. Furthermore, inclusion of operations for utilizing an associated database for storing data and extracting documents therefrom allows the XI system to operate with the reduction of data being transmitted to and received from the external processing systems. In this technique, the XI system is improved by reducing data transmission requirements, reducing amounts of data processing and conversion overhead and eliminating excess data storage outside of the XI system itself.

Abstract: A network apparatus configured to perform data communication using an address includes a value input unit configured to input a value describing at least one part of the address, a first mark input unit configured to input a mark for separating a plurality of values describing the address in a plurality of parts, and a second mark input unit configured to continuously input a plurality of marks.

Abstract: A method for eliminating moire in scanned digital image comprises the steps of using an average circuit for taking weighted average and error diffusing a gray level difference between an error diffusion pixel Gij and neighbor pixels to neighbor to obtain output image pixel Y?ij; using a second adder for subtracting the error diffusion pixel Gij from the output image pixel Y?ij to obtain a neighbor image error dij; using a error filter H(z) to process the neighbor image error dij to obtain a corrected pixel error H(d(i,j)); and using a first adder for adding the corrected pixel error H(d(i,j)) and the input image pixel Yij to obtain the corrected error diffusion pixel Gij, and then jumping to first step until all pixels being processed. The method provides real time treatment for eliminating moire and provide smooth image.

Abstract: A method for multi-toning an input digital image having input pixels with two or more color channels to form an output digital image having modified output levels. The method includes producing shifted error signals for each color channel, weighting the shifted error signals to determine weighted error signals for nearby pixels that have yet to be processed; producing shifted weighted error signals; and adjusting the input levels for the nearby pixels responsive to the shifted weighted error signals.

Abstract: An error diffusion processing circuit includes an error diffusion processing unit and a noise signal unit. The error diffusion processing unit generates a first output image signal of a first pixel by carrying out an error diffusion process, based on an inputted first input image signal of the first pixel. The number of gray tones of the first output image signal is smaller than that of the input image signal. The noise signal unit which generates a noise signal and outputs the noise signal to the error diffusion processing unit. The noise signal is inputted into a feedback loop of the error diffusion process.

Abstract: An error diffusion method applied to halftone processing for image data. The image data comprise a plurality of pixels. The method comprising the steps of dividing the image data into a plurality of image blocks; selecting one of the pixels belonging to each of the image blocks as a target pixel, wherein the target pixel is located on the boundary of the corresponding image block; assigning a predicted error to the target pixel; and executing the error diffusion method on the rest of the pixels of the image blocks according to the predicted error of the target pixels of the image blocks. When the error diffusion is performed, target pixels are found in the image block and then predicted errors are assigned to the target pixels in order to calculate their output values. The target pixels are located at boundaries of the image blocks, and the predicted errors may be 0 or the transversal or longitudinal errors outputted from the pixels above the target pixels.

Abstract: A method of embedding an image into two images by performing a digital halftoning process on a Cartesian product of color spaces to embed the image into the two images. A digital halftoning process includes an iterative isotropic halftoning process. The iterative isotropic halftoning process for each iteration if Outimage has not changed between two iterations or maximum number of iterations reached, then exit the iterations loop.

Abstract: The present invention relates to error diffusion logic in which three partial diffusion error values are produced in a pipelined manner and then summed together when the last partial error value is produced. The resulting summed error can be used to adjust a target pixel in a sequence of pixels or stored in a buffer until further corresponding partial error is produced for adjusting the target pixel.

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: The invention provides a printing method of performing printing on a print medium. The method includes: generating dot data representing a status of dot formation on each of print pixels of a print image to be formed on the print medium, by performing a halftone process on image data representing a input tone value of each of pixels constituting an original image; generating the print image by combining forward pass dots with backward pass dots in a common printing area in such a manner that each main scan line includes both the forward pass dots and the backward pass dots, the forward pass dots being formed on a plurality of pixels of a first pixel group in a forward pass of main scan of a print head, the backward pass dots being formed on a plurality of pixels of a second pixel group in a backward pass of main scan of the print head.

Abstract: A method for halftoning includes the steps of defining a first set of weight sets, and defining a second set of weight sets. A first error associated with a first pixel location of a plurality of pixel locations is diffused to a first neighboring at least one pixel location using a first weight set selected from the first set of weight sets, and a second error associated with a second pixel location of said plurality of pixel locations is diffused to a second neighboring at least one pixel location using a second weight set selected from the second set of weight sets. The first diffusing step and the second diffusing step are alternately performed along each scanline in the image to reduce visual artifacts.

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: In an image processing apparatus which performs an error diffusion process to multivalued image data consisting of plural density components and outputs a result of the error diffusion process, the process result from a first error diffusion unit performing the error diffusion process based on a density value of a first density component included in the plural density components or the process result from a second error diffusion unit performing the error diffusion process based on the density value of the first density component and a density value of at least one density component included in other density components is selected according to a predetermined condition. Thus, even in an image process is performed to a larger number of gradations, a high-speed process can be achieved with simple structure, and the error diffusion process can be effectively performed to a shift of dot apply positions.

Abstract: An image processing apparatus calculates a deformation direction and a deformation ratio of halftone dots, based on a printing condition including a printing direction, a printing speed and the like. Then, the image processing apparatus deforms halftone data, based on the calculated deformation direction and deformation ratio, and generates a halftone image by using the halftone data subjected to the deformation. The generated halftone image is composed of halftone dots deformed in accordance with the printing condition. Thus, the halftone dots are satisfactorily recorded on a printing sheet, and the density gradation of an image is accurately reproduced.

Abstract: An image forming device for forming an image on an image carrier using a different grayscale reproduction method for each of two or more different attributes contained in portions of the image. The image forming device forms a different standard pattern in one-to-one correspondence with each different attribute contained in the image portions, using a grayscale reproduction method used for reproducing image portions containing the attribute, detects density of each standard pattern formed by the standard pattern forming unit, sets, for each different attribute, a condition for correcting grayscale of the image portions containing the attribute, in accordance with the detected density, and corrects grayscale of the image portions in accordance with each condition set by the correction condition setting unit.

Abstract: An error diffusion processing method includes determining a binary value of an input pixel according to a grayscale level of the input pixel, searching a nearest pixel that has the same binary value as the input pixel, and comparing a measured actual distance with an ideal distance between the two pixels, so as to compute a first adjustment value. By applying a noise array to an input image, a second adjustment value is also computed according to a noise value of the input pixel. Based on the first and second adjustment values, a threshold is adjusted to determine the binary value of the input pixel. The adjusted threshold is compared with the grayscale level of the input pixel, and according to the comparison result, the binary value of the input pixel is determined. By diffusing an error value, which is a difference between the grayscale level and the determined binary value of the input pixel, to neighboring pixels, the grayscale level of the neighboring pixels is changed.

Abstract: A device to translate an input pixel value to an output pixel value for a current pixel includes a diffusion block to produce a diffusion error to add to the input pixel value to produce a diffused pixel value. In addition, the device includes a feedback modulation block to generate a threshold value, the threshold value determined using a value of an earlier output pixel value, the earlier output pixel value occurring at a predetermined number of pixels prior to the current pixel. Furthermore, the device includes a quantizer to compare the diffused pixel value to the threshold value and based on the comparison to select a value for the output pixel value.

Abstract: In a halftone module, it is judged whether or not the value “rate” for each pixel is greater than zero (0). In other words, it is judged whether or not the eight-bit input data Iin of each pixel is around a half of the relative density value for a small dot of a corresponding color. If the eight-bit input data Iin of the subject pixel is near to a half of the relative density value for a small dot, noise is added to the threshold values Ta, Tb, and Tc. The noise-added threshold values Ta?, Tb?, and Tc? are used in the comparing process.

Abstract: A method of processing image data when generating multi-level data having arbitrary levels with arbitrary level spacing. The method scales the value of the input pixel to a common level spacing in relation to the arbitrary level spacing in which the input pixel resides. The scaled input data is then treated and processed in the same manner as processing image data with a binary output. The same processing functions, operations and values can be readily applied to data within each level without regard to the level spacing or output levels.