Abstract: A 2-pixel averaging unit (101) halves an input image in the subscanning direction, and a multi-level error diffusion unit (102) performs multi-level error diffusion processing. A 2-pixel reconstruction unit (103) replaces each pixel with two pixels adjacent in the subscanning direction. A density value exchange unit (104) exchanges pixel values adjacent in the subscanning direction in each of 2×2 pixel blocks arranged in a checkered pattern in the image after replacement. High-density blocks each serving as a set of high-density dots and low-density blocks each serving as a set of low-density dots can be generated as 2×2 pixel blocks. The exposure region can be concentrated in PWM conversion.

Abstract: The transfer of a duplicate electronic document between image forming devices is done with an electronic document that is formed of only resolution-independent vector data and the like, and a normal printing of the duplicate electronic document or printing of different resolution is performed by developing the vector data. In high-quality printing of the duplicate electronic document, a Fill Map included in the original document the information indicating the location of an electronic document of copy source that is embedded in a metadata specifies is obtained, and this printing is made using the Fill Map.

Abstract: Machine-enabled methods of, and system, and processor readable media, embodiments for, tone quantization error diffusion, comprising a first stage process and a second stage process, where the quantization and error diffusion steps may be completed for lines scanned according to the first stage, and the quantized pixels may be tested to determine the actual output halftone pattern of the pixels. The quantized pixels may be tested to determine their actual output halftone pattern and threshold levels may be determined by measuring dot intensities for the output device, e.g., a multi-functional peripheral device.

Abstract: An image processor capable of detecting whether an image formed on a recording medium by the image forming apparatus is defective or non-defective with as high accuracy as possible and at high speed. A sheet-surface portion-determining section determines sheet-surface portions of a non-defective formed image on a pixel basis, and stores data of the sheet-surface portion/non-sheet-surface portion distribution, and extracts smallest RGB pixel values from image data of a group of pixels determined to correspond to a sheet-surface portion, to form RGB offset signals based on the smallest values. A sheet-surface portion determination-based offset section subtracts the values of the offset signals from the image data (RGB) of an inspection object. An image quality-determining section determines whether a formed image on the object is defective or non-defective on a pixel basis, using the most significant 1-bit RGB values subjected to the subtraction and the distribution data.

Abstract: The present invention discloses an image processing controller includes: a pixel number determining unit determining the number of print pixels included in the pixel block based on a gradation of a pixel of the pre-conversion image data; a print pixel location unit filling the pixel block with the print pixels in the rows or columns and executing a first location mode where the print image becoming a fraction in the row or column is drawn in a random direction or a second location mode where the print image becoming the fraction in the row or column is drawn near to the circumjacent pixel block having a larger number of print pixels; and a switching unit switching between the first and second location modes to be executed by the print pixel location unit based on predetermined information possessed by the pre-conversion image data.

Abstract: In an image processing device, the memory stores conversion characteristic information corresponding to respective recording portions of an image recording device that records an image at a recording medium while moving a recording unit, which is provided with a plurality of the recording portions arrayed in a first direction, relative to the recording medium in a second direction that is perpendicular to the first direction, the conversion characteristic information expressing conversion characteristics for converting image data in units of one pixel. The first processing unit performs conversion processing along the first direction, continuously converting respective sets of pixel data aligned in the second direction, using conversion characteristic information that corresponds to the recording portions. The second processing unit performs image processing in the order of processing by the first processing unit.

Abstract: A halftoning process includes: receiving CMYK input pixel data in terms of continuous tone input data values for cyan, magenta, yellow, and black colors converting the CMYK input pixel data to modified CMYKRGB* pixel data that define the input pixel in terms of error-adjusted continuous tone data values quantizing the modified CMYKRGB* pixel data to derive intermediate output CMYKRGB pixel data in which the cyan, magenta, yellow, black, red, green, and blue colors are each defined by either a first quantized value that represents no color or a second quantized pixel value that represents full color converting the intermediate output CMYKRGB pixel data to CMYK output data.

Abstract: In a matrix area, a plurality of linear areas each of which extends in a tilt direction tilted relatively to row and column directions are arranged in a direction perpendicular to the tilt direction without spaces, and the plurality of linear areas are alternatively assigned to first and second element groups along an arrangement direction. One element is specified in each element group and subsequently process of specifying an element farthest from specified elements, is repeated to acquire a turn-on order of dots with increase in gray level in one grayscale range and a turn-off order of dots with decrease in gray level in the remaining grayscale range, and a threshold value of each element is determined according to these orders. Thus, generated is a threshold matrix capable of reducing graininess in a halftone image with directionality in the tilt direction, and improving the reproduction of thin lines and characters.

Abstract: A technique for performing high-quality cluster type FM halftone image output without “anisotropy” or “sweep out texture” phenomenon is provided. An error diffused to a current pixel position and a random number RND are added by an adder to multi-level pixel data as a subject of binarization, and supplied as pixel data Pxy to a selector. The selector compares the pixel data Pxy with thresholds, and supplies the pixel data Pxy to one of a highlight portion processor, a dark portion processor and an intermediate portion processor. The highlight and dark portion processors refer to already-binarized results within a range determined in accordance with the value of the input pixel data Pxy, and determine a binarization result Qxy. The intermediate portion processor compares a threshold, which monotonously increases in accordance with the value of the pixel data Pxy, with the pixel data Pxy, thereby determines the binarization result Qxy.

Abstract: An information processing apparatus processes, for each pixel, multivalued image data for a unit area of a recording medium, so as to form an image on the unit area with a plurality of relative movements between a recording head and the recording medium. The apparatus has a selector that selects a first processing mode for dividing the multivalued image data into a plurality of pieces of multivalued image data corresponding to the plurality of relative movements, and then quantizing each of the plurality of pieces of multivalued image data, or a second processing mode for quantizing the multivalued image data into quantized image data, and then dividing the quantized image data into a plurality of pieces of quantized image data corresponding to the plurality of relative movements. The selector selects the processing mode based on a content (attribute, grayscale, color, etc.) of the multivalued image data.

Abstract: Machine-enabled methods of, and system, and processor readable media, embodiments for, tone quantization error diffusion comprising a first stage process and a second stage process. where pre-calibrated index tables may be applied by which quantized pixels may be expressed according to halftones.

Abstract: An image forming apparatus switches a line of image data, to be read out from a storage unit, to another, depending on a position in the line in a scanning direction such that the curving of a scanning line is offset, and reducing trouble in reading out image data in units of rectangular image data blocks A data processing section performs image processing based on a plurality of rectangular image areas generated by dividing image data stored in a memory section. An image reading unit reads out the image data as the rectangular image areas, and transfers the rectangular image areas to the data processing section. A printer section forms an image by scanning a photosensitive member with irradiation light based on the rectangular image data areas. A DMA controller stores positional information indicative of line-switching positions. The rectangular image data areas are read out according to the positional information.

Abstract: A printing system is disclosed. The printing system includes an image processor to rasterize a received print job and to perform a halftone by comparing a first threshold value from a threshold matrix to a first image component sample, comparing the first threshold value to a first number of sequential image component samples neighboring the first sample if the first threshold value is less than the first sample and comparing the first threshold value to a second number of sequential image component samples neighboring the first sample if the first threshold value is greater than or equal to the first sample.

Abstract: A band plotting processing unit analyzes input data to plot in pixel units an image of RGB data corresponding to a character image to be printed, analyzes the input data to generate micropixel RGB data of a low resolution and micropixel shape information (DOT information) of a high resolution. The low resolution image is then converted to a high resolution output image based on the RGB data, the DOT information, and the micropixel RGB data stored in a main memory.

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: An image processing apparatus is provided that restrains image quality deterioration of image data read with a resolution in a sub-scanning direction set lower than a resolution in a main scanning direction from a document containing text, halftone photographs, line drawings, photographs, etc. An image processing apparatus performs the tone reproduction processing by applying error diffusion processing to the image data that has undergone processing of making the resolution in the sub-scanning direction equal to the resolution in the main scanning direction when the resolution in the sub-scanning direction is lower than the resolution in the main scanning direction and applying dither processing to the image data in other case. When the resolution in the sub-scanning direction is lower than the resolution in the main scanning direction, the halftone processing is applied to the entire image data that sharpness and smoothing processing has been performed.

Abstract: Halftoning apparatus and method that may generate and employ average values and shifts are described herein. The apparatus may include an unpacker to determine shifts and average values for a plurality of input pixel values, each pair of average value and shift being associated with a corresponding pair of the input pixel values. The apparatus may further include a halftone core coupled to the unpacker to receive the shifts and the average values from the unpacker and to generate pairs of output pixel values based at least in part on the received shifts and average values, wherein the output pixel values are for generating pixels of an image.

Abstract: A quantizing unit, error detector, error diffusion matrix, and adder quantize a pixel of interest of an input image by an error diffusion method. A calculation unit and gain adjuster calculate a value to be added to the pixel of interest with reference to quantized pixels. The adder adds the calculated value to the pixel of interest. A control unit controls the calculation of the gain adjuster.

Abstract: A computer-readble medium stored with a program causing a computer to quantize a gray level causes the computer to perform a pixel selecting process; determining a noise use rate indicating the degree to which a dither matrix noise has an influence on the quantization and an error use rate indicating the degree to which an accumulated error has an influence on the quantization and determining the noise use rate and the error use rate corresponding to the corresponding pixel depending on the gray levels of the pixels sequentially selected in the pixel selecting process; and performing the quantization on the gray levels of the pixels sequentially selected in the pixel selecting process and performing the quantization using the dither matrix noise based on the noise use rate corresponding to the corresponding pixel and using the accumulated error based on the error use rate corresponding to the corresponding pixel.

Abstract: A print method and apparatus for minimizing effects of error in repositioning during printing process may include generating successive scans of a recording head, wherein the scans may partially overlap to account for the error in repositioning. As an example, after the recording head makes one scan across the document being printed, the document (or the head) may be repositioned for the next scan so that several print elements of the recording head are aligned to lie between certain rows of dots printed in the previous scan, resulting in a higher number of rows in the overlapping portion of the scans. Additional features may include varying the row/column arrangement of dots in the overlap portion, or performing error diffusion and correction for different areas of resolution in the scans.

Abstract: An image processing apparatus includes a dividing portion that divides input multivalue image data into a plurality of bands, an error diffusion process portion that carries out an error diffusion process on each divided band to quantize each pixel, and a controlling portion that controls the dividing portion and error diffusion process portion. The error diffusion process portion, following control by the controlling portion, operates in a first mode to repeat the error diffusion process not accompanying quantization given times on each noted pixel included in a given line of the each band (head line, etc.), and operates in a second mode to carry out the error diffusion process on the each band sequentially from the head line of the each band on the basis of an error value obtained in the first mode to put out quantized data.

Abstract: Quantizing means generates a quantized density and a quantization error component for a target pixel in a plurality of pixels. A subtracter calculates, for the target pixel, a quantization error correction component by subtracting the density of the target pixel contained in preliminary ejection data from the quantization error component output from the quantizing means. An allocator allocates the quantization error correction component calculated by the subtracter to a plurality of the pixels around the target pixel. The quantizing means outputs the quantized density and the quantization error component of the target pixel by performing an addition using the density of the target pixel contained in the image data, the density of the target pixel contained in the preliminary ejection data, and the accumulated diffused error component assigned to the target pixel by the allocator when other pixels are quantized.

Abstract: An image forming apparatus includes a resolution conversion unit that integrates n pixels that are contiguous in the sub-scanning direction, and that determines an average value of pixel values of the n pixels as a pixel value of integrated pixels, a quantization unit that quantizes the pixel value of the integrated pixels to N levels, an image analysis unit that performs first determination processing for determining whether the difference between the pixel values of the n input pixels exceeds a threshold value set in advance, and second determination processing for determining whether a direction in which the pixel values of the n input pixels becomes greater is a forward direction of the sub-scanning direction or an opposite direction, and a pixel selection unit that determines n output pixels, based on the results, from a quantization result of the integrated pixels.

Abstract: A method for improving printing quality of a digital image using error diffusion screening including the steps for each pixel in a digital image: a) initialize weighted error diffusion value; b) translate first value (220) of each pixel of the digital image to a second value (916); c) translate the second value of each pixel of the digital image to create a third value (920); d) translate the third value of each pixel of the digital image by adding the error diffusion value (216) to create a fourth value (224); e) generate a quantization value for each pixel in the digital image by using at least one threshold value; f) perform geometrical distribution in space of the first quantization (924) utilizing a first pixel mask (1604) and possibly a second pixel mask for setting pixels in designated areas defined by the pixel masks; and g) update said error diffusion value and go to step (b) till all the pixels of the digital image are treated.

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: An image processing apparatus configured to generate recording data used in an image forming processing for carrying out an image formation by performing a recording scan by plural times on a same image region on a recording medium, includes a division unit for dividing input image data into image data for each recording scan, a quantization unit for quantizing, based on the divided image data for each recording scan, the image data for each recording scan, and a generation unit for generating, based on the quantized image data for each recording scan, recording data for each recording scan, in which the division unit divides the input image data into the image data for each recording scan based on a division rate periodically varying in accordance with a spatial position of an image represented by the input image data.

Abstract: An image compensating method. First, multiple scanning lines are used to scan a document and a longitudinal black and white pattern, in order to produce the actual gray level value for multiple pixels with respect to each of the scanning lines and the document, as well as a correctional gray level value for complete black and a correctional gray level value for complete white with respect to the longitudinal black and white pattern. Then, the compensational gray level value with respect to the actual gray level value for each of the pixels is obtained according to the correctional gray level value for complete black, the correctional gray level value for complete white, the theoretical gray level value for complete black, the theoretical gray level value for complete white, and the actual gray level value for each of the pixels. Then, the procedure is complete.

Abstract: An image forming method is disclosed in which an image is formed on commercial printing paper using a high penetration pigmented ink by performing image processing which makes use of dot patterns corresponding to an output halftone level.

Abstract: An image processing apparatus includes a first edge extracting unit and a binarizing unit. The first edge extracting unit extracts an edge of chromatic components of a color image other than brightness components of the color image. The binarizing unit performs an enhancement process and a binarization process for pixels being extracted as the edge by the first edge extracting unit and performs the binarization process for pixels other than the pixels being extracted as the edge based on the brightness components.

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 quantizing unit, error detector, error diffusion matrix, and adder quantize a pixel of interest of an input image by an error diffusion method. A calculation unit and gain adjuster calculate a value to be added to the pixel of interest with reference to quantized pixels. The adder adds the calculated value to the pixel of interest. A control unit controls the calculation of the gain adjuster.

Abstract: A device for creating print data utilized by a printer is disclosed. The print data includes a coordinate at which a dot is to be formed on a print medium by the printer. The print data creating device is provided with a first device and a second device. The first device chooses a first coordinate from bit-mapped data. The bit-mapped data includes a plurality of combinations of the first coordinate and color information. The first device chooses the first coordinate based on the color information being combined with the first coordinate. The second device creates the print data by converting the first coordinate chosen by the first device into at least two second coordinates which are randomly chosen from at least three second coordinates located in the neighborhood of the first coordinate.

Abstract: Halftoning is performed on a source image. The halftoning includes error diffusion processing of one separation based on error diffusion processing of another separation. The error diffusion processing includes determining a rendered pixel value for the one separation by applying a quantization function for a given pixel. The quantization function is based on both a modified input determined as a function of an error value of a pre-rendered pixel for the one separation and an error value determined as a function of rendered pixel values for the another separation. A rendered image is output, which includes the same plural color separations. The output rendered image is populated with, for the one separation, a rendered pixel value based on the application of the quantization function.

Abstract: A color correction method includes for each of a plurality of color separations of a digital image, establishing a tone reproduction curve in the form of a vector. The vector is a function of a plurality of basis vectors. The basis vectors account for colorant interactions between a primary colorant with which the color separation is to be rendered and at least one secondary colorant with which at least a second of the plurality of color separations is to be rendered. The vector includes modified input values corresponding to input values for the color separation which vary, depending on the input values of at least the second color separation. For a pixel of interest in the digital image, a modified input value for the color separation which corresponds to the input value of the given color separation is identified from the vector.

Abstract: Restriction information on a total colorant amount for a medium is obtained. Patches at grid points in a color space corresponding to a plurality of colorants at which the total colorant amount falls within a restriction represented by the restriction information, and a patch at a point surrounded by the patches are generated. Color values are obtained by measuring the colors of the patches printed on the medium. It is determined based on a color prediction value between the grid points whether the measured color values are appropriate, and if so, a color value at a grid point at which the total colorant amount exceeds the restriction is estimated based on the measured color values. A color separation table is created based on the measured color values and the estimated value.

Abstract: In a first process, initial dot pattern of a predetermined dot rate “a” is created in a first process, and a gradation value corresponding to the dot rate “a” is arranged as a threshold value in the position of the pixel of the threshold value matrix corresponding to the initial dot pattern. Then in a second process, the initial dot pattern or the dot pattern having occurred prior to the second computation is used as the dot pattern of dot rate “b”, and new dots including the dots of the dot pattern of dot rate “b” is generated or any of the dots is removed from the dot pattern of the dot rate “b” by the error diffusion method. Thus, the dot pattern of the next dot rate “b?” with its dot rate having been increased or decreased in the aforementioned procedure is generated.

Abstract: An image processing system including a lookup table having multi-bit printer output levels and an imaging input level. The imaging input level may be associated with a range of input pixel densities. The system further includes a processor configured to compare the imaging input level with one or more preconfigured threshold output values associated with the printer output levels. The imaging input level may be preferentially weighted to select a printer output level having an increased bit depth.

Abstract: A method and apparatus for reducing image artifacts on displays (e.g., electronic paper, etc.) are described. In one embodiment, the method comprises generating pixels of an image for a bistable display using halftoning based on data of one or more previously displayed images.

Abstract: Error diffusion processing is performed for each pixel in each region of an image divided into a plurality of regions, by scanning in both the first and second directions different to each other. A diffusion coefficient set for diffusing, to the pixel of interest to be processed, a quantization error generated upon quantizing a pixel near the pixel of interest is set in accordance with the position of the pixel of interest in scanning in the first direction in the region of interest. The pixel of interest to which an error has been diffused from a pixel position referring to the set diffusion coefficient set is quantized.

Abstract: When the pixel of interest exists at a pixel position where reference of an error buffer is necessary, a quantization error generated in a region having undergone error diffusion processing is obtained from the error buffer. A quantization error generated in error diffusion processing in a region containing the pixel of interest is obtained from an error memory. Diffusion errors are calculated from the quantization errors using an error diffusion matrix. The value of the pixel of interest and the diffusion errors are added, and the addition value is quantized into the quantization value of the pixel of interest. The difference between the quantization value and the addition value is calculated as a quantization error to be stored in the error memory. When the pixel of interest exists at a pixel position where write in the error buffer is necessary, the quantization error is stored in the error buffer.

Abstract: An image processing apparatus includes a first generation portion that generates a first low-gradation image by performing a first process on an input image to reduce the number of gradations of the input image, a second generation portion that generates a second low-gradation image by performing a second process on the input image to reduce the number of gradations of the input image, a density detector that detects a density of the input image, a determination portion that determines, based on the density, a ratio at which the first low-gradation image and the second low-gradation image are blended together, and a mixing portion that blends the first low-gradation image and the second low-gradation image in accordance with the ratio.

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 determining modified output levels using a combined error signal formed from intermediate error signals for each color channel together with an error signal offset value, and adjusting the input levels for the nearby pixels responsive to weighted error signals.

Abstract: For a halftone representation of a grayscale data of an original image of P tones, an output resolution, a screen ruling frequency, and a screen angle are based to set a basic array of L×L pixels, where L is an integer greater than 1, and a number N of tones reproducible by the basic array is compared with P to generate a dither array using the basic array as its sub-array, such that numbers are assigned to pixels of sub-arrays by a prescribed rule, in order between the sub-arrays, starting from prescribed ones of centered and centermost pixels of the sub-arrays.

Abstract: A binary conversion error value as to neighboring pixels stored in an error value storage portion is added to a pixel density of a subject pixel, which is read from an input image storage portion, at a ratio based on an error distribution matrix, so that a modified density is calculated. A determination is made as to whether the modified density is greater than or equal to a threshold value, and an output image is binarized based on the determination, and stored in an output image storage portion. An output density, which is a value of the output image for calculating the binary conversion error value, is set to a value corresponding to a print mode currently set. By subtracting the output density from the modified density, the binary conversion error value generated in the binarization process for the subject pixel is calculated.

Abstract: An image may be quantized into a pattern of dots, e.g., for devices capable of printing dots of variable size and variable color intensity. One may use a pre-determined mapping of the continuous-tone intensity value into a discrete vector of intensity values, and each intensity value may then be processed by a set of binary quantizers. The resulting binary vector may then be mapped into a combination of available dot sizes and color intensities. Through a scalar multiplier, the pre-determined mapping of continuous-tone intensity values may be used as multiple print resolutions.

Abstract: A color image-scanning device has a fixed scan mode and a flow scan mode. In the fixed scan mode, a document is scanned while maintaining the document at a fixed location on a platen glass. In the flow scan mode, a document is fed from an automatic document feeder and is scanned while moving the document. In each of these modes, images are scanned in a main scanning direction and a sub scanning direction. Color registration errors in the main and sub scanning direction caused by an optical factor are corrected in accordance with correction values stored in a memory. Respective correction values for each of the main and sub scanning directions are acquired by scanning a test chart in each of the fixed-scan mode and the flow-scan mode and stored in the memory. Proper correction values are read from the memory depending on the scanning mode selected, and color registration errors are corrected in accordance with the read correction value.

Abstract: The present invention discloses a digital halftoning method. The method comprises steps of: (a1) dividing an original image into non-overlapping blocks; (a2) obtaining a Least-Mean-Square trained (LMS-trained) filter by comparing at least a training image and a halftone result corresponding to the training image (a3) optimizing a class matrix with the LMS-trained filter, which involves the diffused area and the diffused weightings; and (a4) processing the non-overlapping blocks by performing a dot diffusion procedure with the optimized class matrix and the diffused weightings to generate a halftone image corresponding to the original image. A detailed class matrix optimizing method as in the above-mentioned step (a3) is also disclosed.

Abstract: Data processing methods provide a work flow for producing custom screen printed products based on digital images. Disclosed techniques include a work flow for receiving user-supplied images and transforming the images into color separation data and related metadata that can drive screen printing, including previewing the appearance of the products as they will appear when screen printed, for user approval; finding key color components using a filtering and grouping approach; image resolution limiting; structured error diffusion halftoning with an improved random number generator for use in adding blue noise; error diffusion dot spread correction; and others.

Abstract: Flicker occurs in a flicker-noticeable area consisting of pixels with no pixel value variations. An image processing device (100) includes a variance calculation unit (101) that obtains a variance of an area consisting of a target pixel and neighboring pixels included in a first frame, and changes, according to the variance, the rate at which an error generated at the target pixel through tone level restriction is distributed within the frame and between frames. The image processing device (100) includes an error diffusion unit (113) that distributes the error generated at the target pixel to the neighboring pixels included in the first frame based on an intra-frame error diffusion rate and an intra-frame error distribution weight, and distributes the error generated at the target pixel to a target pixel and neighboring pixels included in the second frame based on an inter-frame error diffusion rate and an inter-frame error distribution weight.