Abstract: An image processing apparatus includes an input section and a binarizing section. The input section inputs multilevel image data. The binarizing section binarizes multilevel image data to generate output image data representing halftone dots each having a hollow-structure. The binarizing section enlarges the halftone dots in a predetermined direction preferentially in accordance with the input multilevel image data.

Abstract: A method for the digital screening of a halftone image by using a first screen having an arbitrary desired screen width and an arbitrary desired screen angle. For the method, the threshold value matrix of a second screen with a different screen angle and width is read out and compared with the color values of a halftone image presented. In order also to approximate screens having a particular irrational tangent and to avoid unpleasant sudden exposed device pixels in clear regions, it is proposed to provide at least one second threshold value matrix having X3Y3 addresses, the X3Y3 addresses of the second threshold value matrix are displaced by a factor 1/B in relation to the X2Y2 addresses of the first threshold value matrix, and to read out the second threshold value matrix as soon as an error D between the first and the second screen exceeds a predefined limiting value.

Abstract: Disclosed herein is an image processing method for producing enhanced halftone edges, particularly suited to those edges which only lie upon the background as apposed to those edges which abut other halftone screens. It utilizes a step of defining border pixels and a step of halftoning those border pixels in a different manner than the halftoning applied to the interior region of the tint or image segment. The preferred halftone for the border pixels will be related to the interior halftone by some number of common spatial frequency harmonics.

Abstract: A method of producing a plurality of filter kernels comprised of filter coefficients for use in a sub-pixel rendering operation comprises calculating a plurality of filter coefficients for each filter kernel by dividing a spatial area of an input image that is overlapped by a portion of a spatial rendering area by a total area of the spatial rendering area using floating point arithmetic. The method further comprises multiplying each filter coefficient by a divisor to produce a filter product such that a sum of all filter products produces a filter sum that equals the divisor. Then a binary search operation is performed to find a round off point for the filter sum such that when each filter coefficient is converted to an integer, a sum of the filter coefficients equals the divisor. The filter coefficients are then converted to integers using the round off point.

Abstract: In accordance with one embodiment, apparatus are provided, which include a digital continuous-tone two-dimensional authentic image and an image processor. Tamper message data is provided which represents a tamper message when viewed. Two halftoning screens are provided to be applied to at least a portion of the continuous-tone two-dimensional authentic image, to embed the tamper message data within a portion of the authentic image, in a manner so as to be substantially not visible in a printed or displayed version of the authentic image absent image processing or tampering of the authentic image. The screens include a first screen to apply first elements arranged in a first way, and a second screen to apply second elements arranged in a second way. A halftoner applies the two halftoning screens to visibly portray desired information of the continuous-tone authentic image. The first screen is applied in a limited area of the authentic image and in a form defined by the tamper message data.

Abstract: A disclosed image forming apparatus for recording images includes: an image processing unit to create toner image data on four colors of yellow (Y), cyan (C), magenta (M), and black (K) such that toner images have line-shaped periodic structures; and an image forming unit to form the toner images using coloring materials of the four colors and superposing the toner images on a recording medium, wherein the line-shaped periodic structures of the toner images of the four colors are determined based on screen ruling of 200.0, 180.3, 180.3, and 200.0 for Y, C, M, and K colors and screen angles of 0.0, 146.3, 33.7, and 90.0 for Y, C, M, and K colors.

Abstract: A three-dimensional halftone screen is provided that is suited for multilevel printing. The three-dimensional halftone screen includes a plurality of planes each corresponding to one or more input intensity levels of an input RIPped pixel. Within the planes are screen dots, each associated with one or more output exposure intensity values representing an intensity of an exposure dot corresponding to the input RIPped pixel.

Abstract: A halftone screen generating method includes growing dot centers into uniform binary patterns in an input image, calculating a main distance of each dot center, forming a screen filter by using the main distance, and generating the halftone screen by using the screen filter to form a binary image. The halftone screen generating method controls cluster dots to have a predetermined main distance, and improve a printing quality by growing dot centers uniformly.

Abstract: A method for performing duplex copying of a document having a first side with a first image and a second side with a second image includes scanning only the first side of the document under a first imaging condition to retrieve first information relating to each of the first image and the second image; scanning only the first side of the document under a second imaging condition to retrieve second information relating to each of the first image and the second image; determining from the first information and the second information contents of the first image on the first side of the document; and determining from the first information and the second information contents of the second image on the second side of the document.

Abstract: A method of discriminating a type of recording medium and a discriminating apparatus in which the type of recording medium is discriminated based on a temperature change of the recording medium when the recording medium is heated. A type of recording medium is discriminated based on a phase difference between a pulse signal input to a heating device and a pulse signal output by a detecting device detecting a temperature of a recording medium.

Abstract: An image processing apparatus includes a storage unit that stores a correction amount used to correct color unevenness of an image according to a plurality of halftone screening conditions; and a correction unit that corrects an input image according to the correction amount stored in the storage unit. The stored correction amount includes common information, which is common among the halftone screening conditions, and dependent information, which is dependent on the respective halftone screening conditions.

Abstract: The present invention relates to the expedient supply of differential gloss text into a document image, particularly as when desired in the employ of rendering variable data. A font character is selected and sub-sampled. The sub-sampled result is then scaled up into a full size result. A first halftone cell having a first anisotropic structure orientation is selected and applied to the full size scaled font result while a second halftone cell having a second anisotropic structure orientation is applied to the surrounding background around the full size scaled font result to create a gloss font character. This full gloss font character is then stored as a font representation as callable by the digital front end of a printing apparatus.

Abstract: A method for enabling a program that communicates a document description from a composition system to a printing system to manage variable-dot halftones for use with variable-dot printing devices, comprising the steps of using a selected halftone cell size to choose an array comprising at least one string defining a halftone cell intensity value, said string comprising at least one pixel imbution value, wherein said pixel imbution value is in the range of 0 to P, wherein P is the number of physical appearances that a painted pixel can have; using a selected halftone cell intensity value to choose a string; and painting at least one pixel within a halftone cell according to a pixel imbution value within the chosen string.

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 present invention relates to the expedient supply of differential gloss or other correlation mark text into a document image via a font definition, particularly as when desired in the employ of rendering variable data. A font character is selected and sub-sampled. The sub-sampled result is then scaled up into a full size result. A first halftone cell having a first anisotropic structure orientation is selected and applied to the full size scaled font result while a second halftone cell having a second anisotropic structure orientation is applied to the surrounding background around the full size scaled font result to create a gloss font or other correlation mark character. This full gloss font character or correlation mark character is then stored as a font representation as callable by the digital front end of a printing apparatus.

Abstract: A method (1500) of generating a representation of a page (1000) to be rendered is disclosed. The page (1000) comprises one or more graphic objects (1080, 1090), each being defined by two or more edges bounding a fill. The method (1500) operates by partitioning the page (1000) into a plurality of regions, each region having a corresponding sequence of fills adapted to be composited to generate a colour for each pixel location within the region upon rendering. Then, the representation is generated such that at least two regions reference a common fill sequence.

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 desired number of tonal levels representative of a continuous tone image and means adapted to compress the received image data from a desired number of tonal levels to image data having a lesser number of tonal levels. The system further includes a memory including a look-up table, the look-up table including each of the lesser number of tonal levels and an array containing screen frequency data for each of the lesser number of tonal levels. The system still further includes means adapted for communicating the image data containing each of the lesser number of tonal levels to the look-up table, whereby corresponding screen frequency data is output therefrom.

Abstract: A multiple beam printer system having N laser beams receives print job information from a print host. A rendering application uses a threshold array to generate halftone image data from the print job. The threshold array is defined based on a spot function. The defined screen is non-orthogonal and includes Y pels in a direction that is perpendicular to a scanning direction of the laser beams where Y is an integer multiple of N. A distance between screen dots in pels is preferably equal to an integer multiple of N. The screen dot may be defined by a supercell encompassing two screen dots and having an odd number of pels in a direction that is parallel to the scanning direction. The spot function may include a snap feature that snaps a screen dot to the nearest printer grid pel. The spot function may include scaling to compensate for the distortion of the non-orthogonal screen dot.

Abstract: Systems and methods for adjusting a source image aspect ratio to match a different target display aspect ratio are described. In one aspect, the systems and methods determine that a source image has a first aspect ratio that is different than a second aspect ratio of a target display. Responsive to this determination, primary visual content of the source image is automatically detected. Dimensions and position of a crop of the source image are automatically calculated such that the crop preserves at least a subset of the primary visual content in the crop. Additionally, the crop is based on the second aspect ratio.

Abstract: A method and apparatus for generating a multicolor image using halftone screens employs a dot structure dot growth pattern for one or more of the colors and a line structure dot growth pattern for at least two or more of the other colors.

Abstract: Filtering image information to generate a dithered image includes receiving input image information corresponding to an image generated using a first array comprising a first number of smaller pixels. Intermediate image information is generated from the input image information. The intermediate image information is generated to produce the image using a second array comprising a second number of larger pixels, where the second number less than the first number. A frequency response associated with the image produced using the second array exhibits effects. The intermediate image information is repeatedly filtered to generate updated image information from the intermediate image information and to compensate for the effects. Sub-image information is generated from the updated image information, the sub-image information corresponding to a dithered image.

Abstract: An implementation of a technology, described herein, for efficient and flexible multi-bit halftoning on a marking device, such as a printer. At least one implementation of the technology, described herein, performs multi-bit halftoning with hardware (e.g., circuitry) rather than a programmable processor. Furthermore, at least one implementation performs multi-bit halftoning for a variable number of bits per pixel and a variable resolution. This abstract itself is not intended to limit the scope of this patent. The scope of the present invention is pointed out in the appending claims.

Abstract: A first conversion table defines a plurality of grid points that are arranged in a predetermined color space. The grid points include a darkest grid point that is indicative of a darkest point among all the grid points. The grid points further include at least (N+1) number of grid points that are successively arranged in a predetermined direction from the darkest grid point, N being an integer greater than or equal to one (1), the grid points including an N-th grid point and an (N+1)-th grid point that are located N-th and (N+1)-th among the at least (N+1) number of grid points, respectively.

Abstract: To improve the rendering of a printing, a halftone rendering method is applied. This method optimally comprises a step for the adaptive tiling of the image. This tiling is based on a subdivision of the image by self-similar structures. These subdivisions are locally limited by the local intensity of the image. These local limitations make the tiling adaptive. The result of this tiling is a cloud of sampling structures, each of these structures being associated with a pixel of the image and a label produced during the tiling. The intensity of the pixel, and the label, enable the reading, in a table of correction vectors, of a correction vector corresponding to a shift to be applied to the pixel before it is printed. The table of the correction vectors is pre-computed in using a relaxation algorithm.

Abstract: Successive frames or images of an input image that are presented to the output device are individually halftoned. A starting location within the input image for tiling one of one or more halftone techniques over the frame or image is determined. The starting location is then offset from the previously used starting location after a certain number of frames or images have been halftoned. Any halftoning technique may be used to halftone the frames or images. The halftoned frames or images are then viewed in a sequence in time.

Abstract: A method is described of compositing a plurality of graphical objects to create an image comprising a plurality of parts, where the parts may be a run of pixels along a scanline or a region of the image. For each part of the image to be composited, the method identifies a set of the graphical objects that contribute to the part, and determines one or more required bit depths for compositing the set. The set is composited within the part at the one or more required bit depths. Thus selected parts of the image may be generated using a higher compositing bit depth.

Abstract: Image data processing methods, hard imaging devices, and articles of manufacture are described. According to one embodiment, an image data processing method includes accessing image data of an image and comprising a plurality of pixels, defining a plurality of subsets of the pixels, defining an overlapping region comprising image data of pixels located adjacent to a boundary intermediate one and an other of the subsets, independently processing the image data of the one and the other of the subsets individually comprising comparing the image data for respective ones of the pixels with a plurality of thresholds corresponding to respective ones of the pixels, and modulating the thresholds of the pixels of the overlapping region using a common modulation pattern for both the processing of the one and the other subsets.

Abstract: A method and system for rotation-dependent halftone rendering. An image input is received from a scanning system or other source, the received image being either a contone image or an error-diffused mage. If a following right-angle image rotation is to be performed, the image is clustered by a clustering method which yields reduced file sizes with respect to the rotated orientation of the image. If no following right-angle image rotation will be performed, the binary image is clustered by an alternate clustering method which yields reduced file sizes with respect to the non-rotated image. The selective clustering includes dividing the image into a tessellation of cells and then concatenating like bits in each cell in a preferred direction for the rotated or non-rotated image. The clustered image is then rotated if necessary, and compressed.

Abstract: The screened printing data are subjected to a filtering method, the raster information being maintained. Intermediate tonal values are produced by the filtering method, using the binary tonal values, the intermediate tonal values being configured in such a way that, by means of a color space transformation, transformed tonal values and/or intermediate tonal values can be formed which represent a true-to-color proof.

Abstract: In the present invention, in an image output apparatus having a specific resolution, a micro normal random number or a blue noise is synthesized in threshold matrix having a plurality of half-tone centers, having an equal interval between half-tone centers in most vicinity, and having lattice elements addressable at a rational tangent angle, wherein a growth order among half-tones is defined in a defined periodic order.

Abstract: A method of modifying screened image data so that there is no visible seam when the image is printed repeatedly in a circumferential direction, for example using a drum output device. One version applicable to images screened using a supercell includes cutting the image so that the image size in the circumferential direction is an integral number of screen supercells. Another version includes displacing halftone dots in a neighborhood of the seam such that the seam is not visible in a repeated print.

Abstract: The present disclosure relates to providing a user interface for the effective generation of differential gloss images. The user is instructed to indicate the base primary image data, and the desired gloss image data. This data may be displayed for verification and position adjustment by superimposition of the gloss image data upon the base image data. In an alternative, the placement information may be inferred from the position of originals upon the scanner or copier platen and the result may or may not be displayed. By selectively applying halftones with different anisotropic structure orientation characteristics to the base primary image data as directed by the desired gloss image data, a differential gloss image file or hardcopy may be provided.

Abstract: A method for reduction of differential gloss as found in hardcopy image prints. The method comprises selecting a first halftone having a high apparent gloss characteristic and a second halftone having a low apparent gloss characteristic while retaining an identical matching density characteristic to the first selected halftone. a A determination is then made of which areas of the halftone image correspond to potentially high gloss and low gloss regions under normal printing conditions. The first halftone is applied to those portions of the halftone image determined as corresponding to potentially low gloss regions, and the second halftone is applied to those portions of the halftone image determined as corresponding to potentially high gloss regions of the halftone image.

Abstract: The present invention provides a print processing apparatus which enhances the legibility of specific print contents such as a small-sized character. In the step executed in case it is determined by the screen processor that the object type is a character, it is determined whether the character size is equal to or smaller than X point. In case the character size is equal to or smaller than X point, execution assumes a small character size and proceeds to screen processing for small-sized characters. In case the character size exceeds X point, execution determines that the character size is a normal size or greater and proceeds to screen processing for normal-sized characters. The screen processing for small-sized characters performs density setting shifted in the direction of a lower density compared with the screen processing for normal-sized characters.

Abstract: An efficient method and system for eliminating halftone screens from scanned documents while preserving the quality and sharpness of text and line-art is disclosed. The method and system utilizes one or more independent channels with different sensitivities (e.g., Max, High, and Low) to provide high quality frequency and magnitude estimation. The most sensitive channel (Max) derives the frequency estimate, and the remaining channels (e.g., High and Low) are combined to create the screen magnitude. The Max channel is the most sensitive and will usually report the existence of frequencies even when the screen is very weak. Therefore, the screen frequency must be additionally qualified by the screen magnitude. The screen magnitude can be interpreted as the level of confidence that the local neighborhood represents half-toned data.

Abstract: There is disclosed an image processor including a display screen, a color image storage, a monochrome image storage, an image presenter, an image-area designator, a color-data replacer, and an outputter. The color image storage stores color image data constituted by a plurality of pieces of color data. The monochrome image storage stores monochrome image data obtained by converting the color image data and constituted by a plurality of pieces of color data. The image presenter can operate to present on the display screen a color image on the basis of the color image data stored in the color image storage, and a monochrome image on the basis of the monochrome image data stored in the monochrome image storage. The image-area designator can designate at least a part of at least one of the color image and the monochrome image that are presented on the display screen by the image presenter.

Abstract: An image reproduction engine which causes toner to adhere to a development region of certain area located at a certain position within dots according to image reproduction data is utilized for image processing, wherein a halftone is expressed by means of halftone spots formed from a plurality of dots. The centroid of the halftone spot formed from a single dot or a plurality of adjacent dots is shifted from the center of the dot to an arbitrary position, thus achieving desired screen angles or desired pitches of halftone spots. As a result, screen angles related to an irrational tangent can be realized, and the pitches of halftone spots of a plurality of color screens can also be made uniform.

Abstract: The present invention relates to expanding the range of image densities over which the manipulation of differential gloss as may be inherent in halftoned images may be achieved. By selectively applying halftones with anisotropic structure characteristics which are significantly different in orientation while remaining identical in density, a gloss image may be superimposed within an image without the need for special toners or paper. This technique may be enhanced across low and high density areas by application of clear toner. Further, in color systems, light color toner may be applied to low density image areas and dark under-color applied in high density image areas, to expand the range of image densities over which a desired glossmark image will bear an effect.

Abstract: A RIP system (100) includes a multi-screening information generator (102) for generating a multi-screening information file (Dms) which is an XML-format file containing information such as screen ruling, dot shape and screen angle, necessary for assigning a multi-screening operation, and discloses the multi-screening information file (Dms) to outside of the RIP system by storing in a shared disk or a flexible disk. On an input data creation process side, a client machine makes reference to the multi-screening information file (Dms), and thereby assign the multi-screening operation.

Abstract: The amount of moiré in halftone printed images is reduced using unique moiré intensity functions and moiré vectors in a halftoner. In various embodiments, moiré phase angle zones are determined over the full field of an image and high addressability units in the full-field moiré phase angle zones of the image are adjusted, including in an iterative manner, until they significantly reduce the moiré. A useful relationship between halftoner memory locations and moiré phase angle zones in a full field image is determined. The moiré that occurs in a halftone image is quantified and moiré compensation values obtained are then used to generate an inverse moire amount which is used to compensate for the moiré.

Abstract: Adjustment object color space containing movement source partial color space including a color of an object of conversion processing and movement destination partial color space including a color in which the conversion processing is performed so as to inscribe the spaces is handled as a conversion object region. The inside of the conversion object region is moved toward a target color so that coordinates of an adjustment object overlaps with coordinates of a point after movement and the boundary of a movement region moves little or does not move at all. As a result of this, a phenomenon such as a color jump or gradation inversion occurs little in the boundary portion to the outside of an adjustment object region. Therefore, maintenance of gradation continuity of an image of a color adjustment object and prevention of color inversion can be combined to make partial color adjustment.

Abstract: A method for reduction of differential gloss as found in halftone image hardcopy prints. The method comprises selecting either a single halftone or employing two halftones: a first halftone having a high apparent gloss characteristic; and a second halftone having a low apparent gloss characteristic. A determination is then made of which areas of the halftone image correspond to potentially high gloss and low gloss regions under normal printing conditions. An overlay of clear toner is applied to the hardcopy print of the halftone image. In one approach a single halftone is employed to control the physical area coverage of the applied clear toner layer so as to adjust the local gloss across for the determined regions and thereby balance the evenness of gloss across the entire hardcopy print of the halftone image. Greater physical area coverage is provided as controlled by the single halftone in low gloss regions, and corresponding less physical area coverage is provided in the low gloss regions.

Abstract: The present invention relates to creating differential gloss images in clear toner by the manipulation of halftones employed prior to the depositing of the clear toner layer upon a substrate. By selectively applying halftones with anisotropic structure characteristics which are significantly different in orientation although remaining identical in density, a differential gloss image may be superimposed within even clear toner as applied to paper. Further, this technique may be used to enhance color toner Glossmark images across the low and high density areas of application where the differential gloss effect would otherwise be weak.

Abstract: A communication apparatus is provided which makes it possible to print out all data larger than a display screen in one operation. In addition, the communication apparatus reduces time required for print processing and eases a user's stress due to print waiting by diverting the data for display as the data for recording. In addition, the communication apparatus analyzes received data, generates data for display indicating a screen to be displayed on a display unit and generates data for printing from data for display corresponding to a plurality of screens according to an instruction of printing.

Abstract: Historically, the creation of digital line screens was considered to be a subset of the creation of the digital cluster dot screens. The geometric constraints necessary for digital cluster dot screens were imported into the creation of digital line screens. Accordingly, the number of available angles or digital line screens was also significantly limited. In various exemplary embodiments of the systems and methods according to this invention, a digital line screen cell is defined such that the vectors defining the digital line screen cell are not necessarily isometric and are not necessarily at right angles to each other. By using a high-addressability grid that has different resolutions along x and y axis of the grid, the systems and methods according to this invention allow the components of the vectors along the high-addressability direction to be noninteger multiples of the components of the vectors along the other direction of the grid.

Abstract: The patterns can be used to reduce one or more undesirable effects such as moire or colour shift in coloured halftone images. Colour screens in the images are based on a combination of non-orthogonal mesh structures with parcels of printing dots which have common shape and size. Preferably the dots grow in mid tones by extending first towards their second, third or fourth nearest neighbours.

Abstract: An image forming apparatus includes an image processing unit that has line heads that include a plurality of light sources disposed in a line shape in a main scanning direction, causes each light source to emit light onto image data to form pixels on an exposed surface, and performs image exposure, and creates two-dimensional image data to be printed on the basis of an image signal from the outside and an operation instruction. The image processing unit corrects the two-dimensional image data such that a density irregularity is corrected on the basis of light amount data and/or optical characteristic data for each of the pixels for the line heads, according to a correction value created on the basis of the light amount data and/or optical characteristic data for each of the pixels of the line heads.

Abstract: The appearance of edges in an image is improved through precise placement of subpixels within pixel cells that are located on or near edges in an image. Image data is examined to identify a “target pixel” near the edge of an object that represents the object and is adjacent to a “background pixel” that represents only background. The target pixel may represent both the object and its background or it may represent the object only. A “second pixel”, adjacent to the target pixel and representing the object, is also identified. The second pixel may represent both the object and its background or it may represent the object only. The target pixel's location with respect to the second pixel is analyzed to determine the placement of a subpixel within the target pixel cell and the placement of a subpixel within the second pixel cell, such that the edge of the object is well-defined and the density of the object is preserved.

Abstract: In a system, such as in a digital copier, for classifying image data derived from an original image, the image data is classified by type. An algorithm is applied to the gray levels of pixels surrounding each pixel of interest. The algorithm determines whether a local maximum or minimum is part of an image of closely-spaced lines.

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