Abstract: Embodiments are disclosed for generating a vector object that comprises a precise circular halftone representation of an input image. A method of precise circular halftone generation includes receiving an input image, dividing the image into a grid comprising a plurality of cells, determining a color of a portion of the input image associated with a first cell, determining a radius of circular halftone elements to represent the color associated with the first cell, and generating a path object representing the portion of the input image using circular halftone elements having the determined radius.

Abstract: A method for determining and suppressing Moiré pattern, and a circuit system thereof are provided. In the method, a brightness value of pixels of an image can be obtained. For each of the pixels of the image, a detection window is provided for calculating a Moiré pattern response value of a plurality of critical pixels and corresponding adjacent pixels. The critical pixels within the detection window are selected for determining a type of Moiré pattern. After, it is to compare the brightness values of the critical pixels and the corresponding adjacent pixels within the detection window. The comparison results can be used to determine the brightness characteristics of the pixels through a statistical method. Moiré pattern response value and the statistics are used to determine type and position of the Moiré pattern. A color noise suppression process is performed on the pixels to be determined as Moiré pattern.

Abstract: A halftone comprises a first halftone screen and a second halftone screen. The first halftone screen comprises a first plurality of amplitude modulated dots arranged according to a first plurality of rows, the first plurality of rows being orientated according to a first direction and comprising a first dot spacing. The second halftone screen comprises a second plurality of amplitude modulated dots arranged according to a second plurality of rows, the second plurality of row being orientated in a second direction and comprising a second dot spacing. The first direction and the second direction define an angle of 45 degrees or less and a ratio of the second dot spacing to the first dot spacing is less than one.

Abstract: Among other disclosed subject matter, a computer-implemented method includes receiving illustrated content. The illustrated content includes half-tone content. The method includes blurring at least part of the illustrated content. The blurring is performed according to a blur radius. The method includes downscaling the blurred illustrated content to an output size.

Abstract: A method for color grading input video data for display on a target display comprises obtaining target display metadata indicative of a capability of the target display, obtaining input video data metadata indicative of image characteristics of the input video data, automatically determining initial values for parameters of a parameterized sigmoidal transfer function, at least one of the initial values based at least in part on at least one of the target display metadata and the input video data metadata and mapping the input video data to color-graded video data according to the parameterized transfer function specified using the initial values.

Abstract: An image processing device includes a first and a second image processing module including an image processing unit, and a connection module that is connected to the first and second image processing modules, and moves an image data from one image processing module to the other image processing module. At least one of the image processing modules includes a weighted average processing unit that calculates, based on a weighting coefficient included in an attribute value, a weighted average of a pixel value of the input image data and a image processed pixel value, and an output unit which outputs at least one of the image processed pixel value and the weighted-averaged pixel value.

Abstract: An electrophotographic image output device includes an image processor to receive input image data, and a line screen to represent halftone images and have multiple screen angles respectively allocated to different colors including yellow, magenta, and cyan. The line screen satisfies requirements of (A) a predetermined difference is secured between adjacent two of the multiple screen angles; (B) zero is not allocated to any of the multiple screen angles; and (C) among the multiple screen angles determined by the requirements (A) and (B), a screen angle closest to 90 degrees is allocated to yellow among yellow, magenta, and cyan.

Abstract: A method enables primary color values for pixel to be processed before the pixel is rendered. The method includes allocating non-black primary colors as being under black, secondary colors, or tertiary colors.

Abstract: A method is disclosed. The method includes generating a set of points via energy minimization to implement halftone seed pattern.

Abstract: A method for detecting and growing isolated holes in a document image having a plurality of pixels is provided. The method includes isolating the pixels of the image to form a plurality of windows, each window having a target pixel; identifying a hole growth factor to grow an isolated hole in the received image; using the hole growth factor to identify tiered pixel patterns from a plurality of predefined, tiered pixel patterns, wherein each of the tiered pixel patterns having a predetermined hole growth factor; comparing the pixels within each window to the pixel patterns within the identified tier to identify a match between the pixels within the window and at least one of the pixel patterns; and changing a pixel value of the target pixel, when a match is identified, to grow the isolated hole by the hole growth factor.

Abstract: A method for detecting and growing isolated dots in a document image having a plurality of pixels is provided. The method includes isolating the pixels of the image to form a plurality of windows, each window having a target pixel; detecting an isolated dot in the received image; identifying a dot growth factor to grow the detected isolated dot in the received image; using the dot growth factor to identify tiered pixel patterns from a plurality of predefined, tiered pixel patterns, wherein each of the tiered pixel patterns having a predetermined dot growth factor; comparing the pixels within each window to the pixel patterns within the identified tier to identify a match between the pixels within the window and at least one of the pixel patterns; and changing a pixel value of the target pixel, when a match is identified, to grow the isolated dot by the dot growth factor.

Abstract: A system and method converts pixels of continuous image data to pixels of binary image data using a halftone screen corresponding to a predetermined reduced coverage percentage; determines if a target pixel of binary image data is a non-white pixel; compares a window of pixels of binary image data with a predetermined pattern of pixels of binary image data corresponding to the predetermined reduced coverage percentage; determines that the target pixel is a non-edge pixel; and reduces the number of non-white pixels in the binary image data based upon the determination that the target pixel is a non-edge pixel.

Abstract: A printing apparatus which forms dots, according to dot data generated through comparison of a grayscale value of each of pixels with each of threshold values of a dither mask. The printing apparatus forms the dots through division into a plurality of pixel groups having different printing conditions and performs at least a part of the dot formation by the pixel groups in a common region. The dither mask has a second threshold value disposition, with respect to a first threshold value disposition which is each of dispositions of the respective threshold values set such that distribution of dots formed in the common region has noise characteristics having a peak on a high frequency side, in a case where a relative position of the dots between the pixel groups is formed in a target positional relationship which is a target in at least a part of a printing grayscale region.

Abstract: A color measuring device includes: an image capturing unit; a reference chart; a light quantity control unit; a generating unit; a correction unit; and a calculating unit. The image capturing unit outputs image data of an image-capturing range. The reference chart has multiple patches of different densities. The light quantity control unit controls the illumination unit. The generating unit generates first correction data based on image data of the multiple patches illuminated by a first light quantity and generates second correction data based on image data of the multiple patches illuminated by a second light quantity. The correction unit corrects image data of the reference chart and a color measurement target, using the first correction data or the second correction data. The calculating unit calculates color measurement value of the color measurement target based on the corrected image data of the reference chart and the color measurement target.

Abstract: A method and system to generate a moiré-free to all-orders N-color screen-set by a lattice-based screen design the method including choosing a lattice in frequency space with basis vectors u1 and u2 such that (?{right arrow over (u)}1?,?{right arrow over (u)}2?,?{right arrow over (u)}1±{right arrow over (u)}2?)>f min, where f min is the minimum moiré invisible to the human eye, and choosing a set of N pairs of fundamental frequency vectors on the vertices of this lattice to be the screen vectors.

Abstract: A method and system for generating a halftone image from an input image is disclosed. Visible artifacts caused by the correlation of one or more colors or color planes are avoided because the halftone image analysis for one color affects the halftone image analysis for subsequent colors. A printer controller analyzes at least a part of the input image to dynamically set a sequence of the plurality of colors. Halftone image analysis is carried out in the sequence of the plurality of colors to generate the halftone image.

Abstract: Among other disclosed subject matter, a computer-implemented method includes receiving illustrated content. The illustrated content includes half-tone content. The method includes blurring at least part of the illustrated content. The blurring is performed according to a blur radius. The method includes downscaling the blurred illustrated content to an output size.

Abstract: An image forming apparatus forms a color image using image carriers for a plurality of colors by electrophotography. The image forming apparatus stores, for each color, information on the shift amount between an ideal scanning line and an actual scanning line in the main scanning direction on the image carrier. For each color, a color misregistration correction amount calculation unit converts a readout address in a bitmap memory (403), based on the stored shift amount information, and reads out image data. A color misregistration correction unit (404) performs tone correction for the readout image data based on the address, outputting image data containing the value of the decimal part. A multi-level error diffusion unit (405) performs quantization by multi-level error diffusion processing for the tone-corrected image data containing the value of the decimal part.

Abstract: An unnatural color change which occurs when combining trapping and spatial filter processing is suppressed. When image data is input, it is determined whether to perform trapping at the position of the pixel of interest of the input image data, and trapping is performed for the input image data. In addition, spatial filter processing is performed for the pixel of interest of the input data, an output of the trapping and that of the filter processing are weighted, and image data to be output is calculated.

Abstract: A first screen group and a second screen group are stored in an image forming apparatus. In the first screen group, the first region expands with increasing gradation value based on a first rule. In the second screen group, the first region expands with increasing gradation value based on an independent second rule different from the first rule. A screen selector relocates a first portion and a second portion such that the first portion and the second portion are joined by a second region that is not a toner adhesion control target, when the first portion and the second portion are adjacent as a result of the selection of the screen in each unit region of the input image. The first portion includes the screen included in the first screen group, and the second portion includes the screen included in the second screen group.

Abstract: According to the present invention, there is provided a color image forming apparatus which includes image forming units forming images, each for each color component, and superimposes the images of the color components on one another to form a color image. The image forming apparatus includes a scan line changing unit shifting the position of each pixel in a sub scanning direction for each color component of halftone image data to be processed so as to cancel a shift amount of a scan line on an image carrier in each of the image forming units in the sub scanning direction; an interpolation inhibited area determining unit determining an interpolation inhibited area in the image data; and an interpolation unit applying an interpolation process for smoothing a pixel-level shift caused by shifting of image data by the scan line changing unit to the image data excluding the interpolation inhibited area.

Abstract: Provided is a 3-colorant DOD (dot-off-dot) periodic halftone geometry used to render an image. The DOD 3-colorant halftone geometry includes a base colorant halftone screen with hexagonally tiled halftone dots arranged in a hexagonal pattern, the hexagonally tiled halftone dots having a first fundamental frequency vector Vh1, a second fundamental frequency vector Vh2, and a third fundamental frequency vector Vh3, where Vh3 is substantially equivalent to Vh1+Vh2.

Abstract: An image processing apparatus may include a first screen processing unit, a moiré component calculation unit, a first correction unit, and a second screen processing unit. The first screen processing unit performs screen processing on image data to form screen processed image data. The moiré component calculation unit calculates an original moiré component that corresponds to a low-frequency component of the screen processed image data and a low-frequency component of the image data. The first correction unit corrects the image data based on a calculated moiré component. The second screen processing unit performs the screen processing on the corrected image data.

Abstract: An image forming apparatus capable of reducing a stitch effect, an image forming system including the same, and a printing method thereof. The printing method of the image forming system includes inputting image data to be printed; and, if adjacent first and second objects included in the input image data have different LPIs (Lines Per Inch), emphasizing at least one of boundaries of the first and second objects and printing the image data with an emphasized boundary.

Abstract: A method for designing a screen set for color halftoning includes selecting a screen set that includes at least two screens. The screens are applied to a uniform color image so as to form a set of corresponding colorant halftones. The colorant halftones are superposed to form a color halftone. A spatial frequency spectrum of the color halftone is calculated. Maxima of the spatial frequency spectrum that occur at two effective frequencies are identified, the two effective frequencies being located in two adjacent quadrants of a complex spatial frequency space. A magnitude of each effective frequency is compared with a predetermined frequency magnitude. The screen set is accepted for future application for color halftoning only if both effective frequency magnitudes are greater than the predetermined frequency magnitude. Relating computer program product and data processing system are also disclosed.

Abstract: A method for producing a pseudo-stochastic master surface for producing a cover or jacket of a cylinder for contacting printing material, includes providing the master surface with a pseudo-stochastic distribution of microsurfaces. The master surface is produced on the basis of a digital master in a jacket preliminary stage and serves for a preferably galvanic production of a microstructured cover, in which structure elevations correlate with the microsurfaces. The pseudo-stochastic distribution helps to avoid disruptive discernible effects, for example the moiré effect and helps to construct the microstructuring in a targeted manner. A master surface, a method for producing a cylinder cover, a cylinder cover, a machine for processing printing material, a method for producing printed products and a method for microstamping printed products, are also provided.

Abstract: In a method to convert color-describing input print data suitable for graphical output with aid of an output apparatus into color-describing output print data, color proportions, defined by the input print data, of at least one region to be inked with at least two color separations, are determined, and a color space value to be generated with aid of the color separations is determined. An association rule is determined to convert the input print data into the output print data while retaining the color space value. A total areal coverage of areal coverages defined by the output print data of the color separations to generate the color space value is reduced relative to areal coverages of the color separations defined by the input print data. The input print data is converted into the output print data with aid of the determined association rule.

Abstract: An unnatural color change which occurs when combining trapping and spatial filter processing is suppressed. When image data is input, it is determined whether to perform trapping at the position of the pixel of interest of the input image data, and trapping is performed for the input image data. In addition, spatial filter processing is performed for the pixel of interest of the input data, an output of the trapping and that of the filter processing are weighted, and image data to be output is calculated.

Abstract: A set of screens is provided for use in printing respective color separations in a halftone color printing process. This set of screens comprises at least two clustered-dot screens and the frequency and angle parameter values of the screens is such that the lowest frequency moiré produced by any combination of at least two frequency components, taken from the group comprising the first and second screen harmonics, for which the sum of the harmonic orders of the frequency components in the combination is less than a predetermined value, is of a sufficiently high frequency as to be substantially unperceivable to the human visual system; other moirés are also substantially unperceivable to the human visual system. The lowest frequency moiré serves to reduce the visibility of color changes caused by color plane registration variations. A printing system and method employing the screen set are also provided.

Abstract: Disclosed are moiré-free color halftoning methods, apparatus and systems to digitally reproduce an original color image. The disclosed embodiments are particularly useful for rendering a color image with a color printing device. According to one exemplary embodiment, an image forming method utilizes three or four rotated hexagonal screens which can include regular shaped hexagon screens or convex tessellated hexagon screens.

Abstract: A method is disclosed for screening color separations of a lenticular image with a lenticular frequency of the lenticular lenses needed for viewing the lenticular image. An amplitude-modulated halftone image is calculated for each of the color separations at a screen angle and at a screen frequency, the tangent of the screen angle being a rational number. For a specific color separation, a screen angle relating to the direction perpendicular to the image strips of the lenticular image is defined, a pair of whole numbers whose ratio is equal to the tangent of the screen angle is determined, and the screen frequency of the color separation is calculated as the product of the lenticular frequency and the square root of the sum of the squares of the two whole numbers.

Abstract: The present invention is directed to a system and method for halftone screening. A system for halftone screening includes means adapted to receive image data having a number of tonal levels representative of a continuous tone image. The system further includes a memory including a LUT having a number of alternative halftone cell arrangements for each tonal level. Each cell of the LUT consists of a number of device dots describing a particular gray value. For each gray value, there are several alternative cells with different arrangements of the same number of device dots. The LUT is configured with the cells of different arrangements in rows. The rows increase in the number of device dots; hence, each column describes halftone cells of increasing tonal values. The system then communicates the image data having a tonal level to the LUT, and randomly selects a halftone cell arrangement to generate a halftone output.

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: Described is an image processing apparatuses, which makes it possible to accurately remove a periodicity from a halftone dot pattern included in an image. The apparatus includes: a periodicity pattern analyzing section to acquire periodicity information indicating the periodicity of the halftone dot pattern; a smoothing area determining section to determine a smoothing area, constituted by either a pair of rectangular areas contacting with each other or a single rectangular area, based on the periodicity information; a spatial filter creating section to create a spatial filter within which the smoothing area is includible, and in which a weighted coefficient of each of pixels is established corresponding to an overlapping area of a concerned pixel overlapping with the smoothing area; and a smoothing calculation section that applies a convolution arithmetic calculation processing to the image data representing the processing objective image with the spatial filter.

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 method of registering a print between print stages in a printing system is provided. The method comprises: printing a first part of a digital image on a substrate with a first print engine, wherein the first part of the digital image includes a plurality of reference features; scanning image content on the substrate as it is readied for the second print engine; determining the actual positions of the reference features; using the actual positions of the reference features to determine desired adjustments for the second part of the digital image; applying electronic registration according to the desired adjustments to modify image content of the second print to be aligned with content already on the substrate; and printing a second part of the digital image on the substrate.

Abstract: An image processing apparatus may include a first screen processing unit, a moiré component calculation unit, a first correction unit, and a second screen processing unit. The first screen processing unit performs screen processing on image data to form screen processed image data. The moiré component calculation unit calculates an original moiré component that corresponds to a low-frequency component of the screen processed image data and a low-frequency component of the image data. The first correction unit corrects the image data based on a calculated moiré component. The second screen processing unit performs the screen processing on the corrected image data.

Abstract: Color management constraints on the use of selected hypocolorant(s) and a black colorant in the rendering of a given pixel reduce ink or toner usage and/or reduce pressure on an ink limit. Additionally, the enforcement of this mutual exclusivity between the black and the selected hypocolorant(s) allows screen frequencies and angles to be shared between halftone screens used for the black colorant and a selected hypocolorant. This reduces the likelihood of objectionable moiré associated with the use of hypocolorant colorants in addition to the conventional CMY(K) colorants. In some embodiments, color management constraints prevent the use of black colorant for pixels beyond a threshold lightness or luminance. This constraint allows the use of the selected hypocolorants in the region of color space beyond the threshold. The threshold can be a function of hue and/or chroma. In some embodiments the threshold is a constant.

Abstract: Disclosed is an image processing apparatus, including: an averaging processing unit to periodically execute an averaging processing of applying an averaging pattern to a processing target image and replacing each pixel value in a pixel group corresponding to the averaging pattern with an average value of the pixel values; a resolution converting unit to perform a resolution converting processing to the processing target image, the resolution converting processing converting a resolution R1 of the processing target image into a resolution R2 (R1<R2); a screen processing unit to perform a screen processing to a processed image which has been processed by the averaging processing, the screen processing applying a screen pattern to the processed image at the same or almost the same period as that of the averaging processing; and a control unit to control the averaging processing unit, the resolution converting unit and the screen processing unit such that the averaging processing, the resolution converting pro

Abstract: An image display medium displays an image including a first region having a first composite image. The first composite image includes a first display image and a first latent image. The first display image includes at least one of a first halftone dot image and a first line image having a first linearity. The first halftone dot image and the first line image have such densities as are not reproduced by copying. The first latent image includes at least one of a second halftone dot image and a second line image having a second linearity. The second halftone dot image and the second line image have such densities as are not reproduced by copying. The first and second linearities produce different moiré patterns when the first display and the first latent images are enlarged by a first common optical system.

Abstract: Methods and apparatus are provided for dynamically halftoning image data, substantially in real-time. Halftone threshold values are calculated and stored in memory, and halftone output values are calculated for the portions of the image data that will be displayed on a display device. Halftone screen parameters may be modified, and new halftone screen threshold values may be calculated for any affected halftone screens. For unaffected halftone screens, the previously stored threshold values may be retrieved from memory. In addition, the portion of the image to be displayed may be modified, and the halftone output values of the new portion may be calculated and then displayed.

Abstract: The present invention relates to printable security paper that includes a region capable of receiving printed indicia on the front side and on the reverse side which are observable in reflected light and form an image observable in transmitted light, as security element protecting against two-sided copying, characterized in that such region is a screened region having an average overall opacity less than the opacity of the vellum part of the rest of the paper, said screened region being made up from alternations of vellum miniregions, having an approximately constant thickness equal to that of the vellum part of the rest of the paper, and of miniregions of reduced opacity because of their smaller thickness compared with the vellum miniregions. The invention also relates to the security document obtained with this paper.

Abstract: A method and apparatus for rendering image data on a 3D display is disclosed. A first image signal is received and then at least one colour component of the first image signal is rendered in reduced spatial resolution to produce a second image signal. The second image signal is spatial filtered wherein spatial errors and view errors are balanced when reconstructing a full resolution signal for the display.

Abstract: An image correction process that suppresses image deterioration in a printed image is provided. An image correction processing apparatus includes an area setting unit which sets an area comprising a plurality of pixels including an interest pixel, a first correction strength setting unit which adaptively sets a first correction strength for at least the interest pixel in the area based on the number of changes and the changing amount, a first correction unit which executes image correction for a pixel, for which the first correction strength is set, by the first correction strength, a second correction strength setting unit which adaptively sets a second correction strength for at least the interest pixel in the area based on the number of changes and the changing amount, and a second correction unit which executes image correction for a pixel, for which the first correction strength is set, by the second correction strength.

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: An original image is scanned for respective pixels to determine attributes indicating features for respective pixels of the scanned document. Pixel values included in an M×M area (where M is a natural number) including a pixel of interest are weighted, the pixel value of the pixel of interest is changed based on the weighted pixel values, and smoothing processing is applied to pixels included in that area. Upon applying the smoothing processing, a size of a filtering area used for the smoothing processing is reduced to a size of an N×N area (where N is a natural number, with M>N) including the pixel of interest according to the determined attributes.

Abstract: A programmable system for dithering video data. The system is operable in at least two user-selectable modes which can include a small kernel mode and a large kernel mode. In some embodiments, the system is operable in at least one mode in which it applies two or more kernels (each from a different kernel sequence) to each block of video words. Each kernel sequence repeats after a programmable number of the blocks (e.g., a programmable number of frames containing the blocks) have been dithered. The period of repetition is preferably programmable independently for each kernel sequence. The system preferably includes a frame counter for each kernel sequence. Each counter generates an interrupt when the number of frames of data dithered by kernels of the sequence has reached a predetermined value. In response to the interrupt, software can change the kernel sequence being applied. Typically, the system performs both truncation and dithering on words of video data.

Abstract: Disclosed herein is a method and apparatus for moiré-free color halftone printing with up to five color image separations. The method and apparatus utilize a plurality of non-orthogonal halftone screens to produce outputs that are moiré free and form rosettes.

Abstract: Systems and method for digitally reproducing a moiré-free color halftone output image having an embedded correlation-based digital watermark are provided using an enhanced halftone screen set consisting of a halftone screen for each of N colorants forming N color separations (where N?3). The N different uniform rosette halftone screen configurations are generated such that each meets uniform rosette halftone screen conditions. A corresponding three-dimensional threshold array is generated for each halftone screen configuration having a phase shift value as an input. The color input image is halftoned, halftoning each one of the N different color separations using a corresponding halftone screen configuration and three-dimensional threshold array to form a moiré-free color output image having the correlation-based digital watermark embedded therein. A single key can be used to produce a full color image of the output image having the watermark image visible therein.

Abstract: The invention concerns a security document comprising, as security element against recto/verso copying, indicia present on both sides and capable of being viewed under reflected lighting and forming an image capable of being viewed under transmitted light. The invention is characterized in that said indicia comprise lines and form said image with 3D effect.