Abstract: A method for processing video data for display on a display device having a plurality of luminous elements comprising: applying a dithering function based on single ones of said luminous elements to at least part of said video data to refine the grey scale portrayal of video pictures of said video data, computing at least one motion vector from said video data, and changing at least one of the phase, amplitude, spatial resolution and temporal resolution of said dithering function in accordance with said at least one motion vector when applying the dithering function to said video data.

Abstract: An image information acquisition unit obtains first print image information that is binarized with the use of a first threshold matrix. A threshold matrix information acquisition unit obtains information representing the first threshold matrix. A determining unit divides the first print image information obtained by the image information acquisition unit into a plurality of portions, and determines whether each of the divided portions includes contour information, based on the first threshold matrix obtained by the threshold matrix information acquisition unit. A generating unit generates second print image information by performing a re-binarizing operation for each of the divided portions of the first print image information with the use of a second threshold matrix that is different from the first threshold matrix, based on the determination result of the determining unit.

Abstract: This invention provides a method of generating a dither matrix that stores each of a plurality of threshold values in each of elements for determining a status of dot formation of each print pixel of a print image to be produced on a printing medium by carrying out halftone processing on image data.

Abstract: An image forming apparatus, an image forming method, a program, and a recording medium that succeed in reducing recording agent consumption without causing image quality degradation are provided. A modification region processing section detects, out of image data, A locations where a region identification signal provided from a region separation processing section changes from a ground region mode to a character region mode, and vice versa, as the boundary between the ground region and the character region, and thereby specifies a modification region which is continuous with the ground region and overlaps with a part of a periphery of the character region which is contiguous to the ground region. The modification region is assigned color data indicating a color that can be represented by the recording agent for use in ground region formation thereby to generate image data.

Abstract: Techniques are disclosed for selectively dithering only a subset of a digital image. One or more ranges of digits are selected for dithering. Only those pixels having digits within the selected range(s) in the digital image are dithered. The image is printed after being selectively dithered. Digits may be selected for dithering if they have values within the range(s) of one or more non-monotonic regions of a printer transfer function. Dithering may be performed on the subset of the digital image by applying a nonlinear transformation is applied to the image and adding a dither pattern to the transformed image. The result is quantized, and the inverse of the nonlinear transformation is applied to the quantized image to produce a dithered image. The nonlinear transformation is constructed such that the effects of the dither pattern appear only in that subset of the image having digits in the selected range(s).

Abstract: An image processing apparatus of the present invention compares the density value of K-color at each position around a blank character with a reference density value, thereby deciding whether it is necessary to remove other color components. Based on the result of a decision, the apparatus removes the color components. Thus, other color components can be removed only in the region where the density value of K-color is high. Hence, when a background image is an uneven image, a kickback processing can be performed suitably around the blank character.

Abstract: An identifying system is provided for identifying a geometrical element in an image automatically. The image may be retrieved from an image capturing apparatus and is imported in a coordinate system. The identifying system includes: a collecting module for collecting dots from the image as a dot muster and retrieving coordinates of all dots of the dot muster from the coordinate system; a curve fitting and geometrical element identifying module for curve fitting according to the coordinates of all the dots of the dot muster to identify what geometrical element the dot muster is; a storing module for storing the coordinates of all the dots of the dot muster, data produced during the curve fitting process, and result data of curve fitting and geometrical element identifying; and an outputting module for outputting the result data. A related identifying method is also provided.

Abstract: A system/method of color match assessment for electronic documents includes receiving digital data defining a composite electronic document including a raster image object having an edge and a color graphics object bordering the edge of the raster image object. The pixel color values defining the edge of the raster image object are processed to estimate a local color variance of the pixel color values. The local color variance is used to determine if the edge can be color matched to the bordering color graphics object. If the edge can be color matched, a match color for the edge is derived. The match color is associated with the digital data defining the electronic document so that a downstream object color match system can use the match color as needed, e.g., to adjust the color of the bordering color graphics object to ensure a match with the edge of the raster image object when the electronic document is printed using a xerographic printing process.

Abstract: Digital images that are produced by an image forming device may be processed using an edge enhancement technique to reduce the effects of halftone color depth reductions. For each element in the original image, certain detail elements are classified by examining the magnitude of pixel intensity gradients between elements of interest in a first window applied at each element and other elements in the first window. If a first predetermined condition is satisfied, those elements locations are stored. After halftoning, a morphological filter may be applied to the same element locations in the halftone image to enhance the halftone image.

Abstract: An image processing apparatus provided with: an edge correction unit for, based on a level of a pixel value of an edge area of an image, correcting the pixel value of the edge area of the image; and a halftone processing unit for carrying out a first halftone processing on the edge area of which the pixel value has been corrected and a second halftone processing on an area of the image that is different from the edge area, the second halftone processing being different from the first halftone processing.

Abstract: A device for sharpening an image signal for receiving an image signal input, detecting and sharpening the object edge of the image signal input by using a detection period, and outputting an image signal output is provided. The image signal sharpening device determines the switching point of a maximum value signal and of a minimum value signal within the detection period through a switch-point generator and sharpens the image signal input through a signal processing unit. Therefore, the device can enhance the contrast of the edge of the object image and improve image sharpness without causing an overshoots or undershoots of the image amplitude. In addition, a confidence checking unit can be used to ensure the correct detection of the edge of the object image.

Abstract: A method for improving print quality by using lossless image compression (JPEG-LS) technology and system thereof are provided. The detailed characteristics of prediction errors generated during lossless image compression encoding or decoding process are retrieved and fed back to a halftone print mode of the printer and are used to adjust the halftone print mode.

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: Regions within a scanned document are labeled according to content. These labeled regions allow for particular enhancement and sharpening methods to be applied. The labeled regions may be further leveraged in subsequent rendering of the scanned document on a printer or other output device and/or in storing the scanned document.

Abstract: Systems and methods for improving image quality of image data to be rendered may be provided using multiple mask MRC files. Such a method may involve processing a first binary bit map of image data to generate a processed binary bit map, assigning an edge tag to at least one pixel in the processed binary bit map, and assigning a gray/color value to at least one pixel in the processed binary bit map based on values of corresponding pixels in the first binary bit map. A system may include a processor that performs such processing and assigning, an image data source that supplies image data of an original image, and an image rendering device that provides a rendered image of the original image based on the at least one assigned edge tag and the at least one assigned gray/color value.

Abstract: An image forming apparatus provides enhancement of image quality. The image forming apparatus includes a window generating unit to generate a main window of a predetermined size using a Lines Per Inch (LPI) and an angle of a dithering mask, and to generate a plurality of subwindows within the generated main window, a determining unit to determine the presence of an edge area by applying the plurality of generated subwindows to a binary image and according to pixel values of the binary image that correspond to the subwindows, and a control unit to determine a dot size of a central reference pixel at the center of the main window, according to the presence and absence of the edge area. Because image quality is enhanced adaptively according to edge and smooth areas, print quality improves.

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

Abstract: A smoothing process is performed on image data to obtain improved image quality. Output image data is switched among image data subjected to smoothing, image data subjected to second bit conversion, and image data subjected to pseudo halftone representation process. In this manner, jaggies at edges can be smoothed even in multilevel image data subjected to image forming process such as screen processing. Smoothing for image data with degraded image quality due to, for example, lossy compression such as JPEG compression can also be achieved. Furthermore, degradation in image quality that occurs when a conventional smoothing process is applied to image data subjected to particular image processing can be avoided.

Abstract: There is disclosed in embodiments methods relating to the compression of printing hints. The method in embodiments generates a first set of image pixels having corresponding printing hints. The printing hints are then adjusted to produce a second set of image pixels processed in such a way that an end printed result is visually equivalent to a printed result using the first set of image pixels thereby reducing the entropy in the printing hints. The method improves the compression ratio of an image using printing hints by adjusting the printing hints of pixels that are zero or fully saturated. The printing hints are adjusted in such a way to reduce the complexity of the printing hints.

Abstract: An image processing apparatus includes an edge amount calculating device configured to calculate edge amounts of an image in a plurality of directions for each of a plurality of frequency bands of the image. A character edge area determination device determines, based on the calculated edge amounts, whether or not a selected picture element of the image is of a character edge area. A sharpness control device corrects a frequency characteristic of the image by performing a first correction to the edge amounts when the selected picture element is determined to be of a character edge area by the character edge area determining device, and by performing a second correction to the edge amounts when the selected picture element is determined not to be of a character edge area by the character edge area determining device.

Abstract: A method and system to convert an electronic image file described in a page description language containing both contone and non-contone image objects to an intermediate binary format image. The intermediate format image separately encodes the contone and non-contone image objects. The contone image objects are edge-tagged. Prior to printing, the intermediate binary format page image is separated into the contone and non-contone image objects. The contone image objects are converted back to a contone form using the edge tagging to modify the filter weights of a digital filter. The non-contone image objects are converted to contone form by means of a pattern matching scheme.

Abstract: The present invention is a method of image data processing that includes determining whether the image data indicates photodiode saturation, and removing contouring from the image data caused by the saturation. The contour artifact removal is accomplished by adding a random number to adjusted photodiode data from an extended range imager when the data from the imager indicates that the photodiode has been saturated. The adjusted photodiode data is a sum of photodiode data and spillover rate adjusted diffusion data.

Abstract: A method for selecting a halftoning mode to be applied to regions within an image. The method operates on received image data to identify low-level regions within the received image data. The low-level regions are defined and separated by edges. Pixels that are not separated by edges are considered to belong to the same region. After the regions have been identified, low-level image attributes for the image data within each region are compiled. A halftoning method suited for the image data within the region can be selected based upon low-level image attributes.

Abstract: An input image is transformed to produce an output image. Pixels occurring at edges that represent detail within the input image are detected to produce an intermediate image. Background fill representing textures of the input image is generated. The background fill and the intermediate image are combined to produce the output image.

Abstract: Techniques for securely displaying text on a display panel involve destroying spatial and temporal correlations in an otherwise uniform visual field. The techniques render the displayed text secure with respect to attempts to copy the text using a video capture device or still-picture camera. The techniques also render the displayed text unreadable to casual over-the-shoulder viewing by strangers outside of a certain narrow reading area.

Abstract: An edge information detection section detects edge information corresponding to a spatial change in a pixel value in a predetermined region by using a two-dimensional first differential filter with respect to an input image signal. An edge intensity detection section detects an edge intensity by using a first threshold value with respect to the edge information detected in the predetermined region. A flatness detection section detects a degree of flatness by using a second threshold value smaller than the first threshold value with respect to the edge information detected in the predetermined region. A determination section generates a two or more valued determination signal by determining the edge information in the predetermined region from the edge intensity and the degree of flatness.

Abstract: A novel image forming apparatus which makes gray-scale by performing at least one of operations including a manipulation of a plurality of dots arranged in a form of matrix, a single-dot-based density adjustment, or a single-dot-based size adjustment, includes a dot status detector and a density adjuster. The dot status detector detects an occurrence in which a dot exists at a focus dot position and no dot exists at positions immediately adjacent to the focus dot position in the main scanning direction. The density adjuster adjusts a writing level of the dot at the focus dot position so as to make the gray-scale smooth when the dot status detector detects the occurrence.

Abstract: A character-edge detecting unit detects a character edge area in an image. A character-inside-area detecting unit detects a character inside area in the image. A density-information detecting unit detects density information in the image. An image processing unit executes a predetermined image processing according to results of detecting the character edge area, the character inside area, and the density information. The image processing unit applies different image processings or different image processing parameters to the character inside area based on the density information.

Abstract: Even when a jaggy occurs in an original image, the image is accurately enlarged and a good image cannot be obtained as a result. In the case of performing pixel interpolation on an image in a dot matrix state, image data is entered in step 100, the whole image is scanned while shifting a marked pixel, and whether or not an edge exists in the direction of 45 or 135 degrees by using the marked pixel as a reference is detected in step 115. When an edge at 45 or 135 degrees exists, the edge is smoothed in the direction of either 45 degrees in step 120 or 135 degrees in step 125. After that, pixel interpolation is carried out irrespective of the presence or absence of an edge. Consequently, when there are irregular edges, it can be prevented that an image is directly subjected to pixel interpolation and a jaggy occurs.

Abstract: Selective edge softening and selective edge dithering is introduced into an image representation to improve local control where halo problems are expected. Selective areas of dilation are isolated and separately dithered or halftoned, the result of which is then swapped back into or substituted for the stored original image. In this manner misregistration and color plane-to-plane interactions can be compensated for in plural image forming station architecture systems. The same technique is also valuable in monochrome systems as an aid to overcoming edge displacement and slow toner problems when the selective edge softening is selectively applied to edges which are in particular perpendicular to the fast scan direction.

Abstract: A method of printing multiple images with differing line screen frequencies with a printer is print sensitive to differing line screen frequencies, the method comprising the steps of: converting the images into a digital bitmap comprised of an array of pixels wherein each pixel is assigned a digital value representing marking information; defining each pixel as either a background pixel, interior pixel, or an edge pixel; reassigning the digital value of the interior pixels to a fixed interior pixel value; and reassigning the edge pixel values so as to minimize print sensitivity to differing line screen frequencies between images.

Abstract: The present invention relates to an image processor provided in apparatuses such as digital copiers and printers, and that distinguishes between a character edge region and a continuous tone region of an original image and switches the tone reproduction processing between the regions.

Abstract: An image processing apparatus includes a first filtering process device configured to perform a predetermined space frequency characteristic conversion process to input image data having multiple-level gradation. A conversion process device performs a gradation characteristic conversion process to an output result of the first filtering process device. A second filtering process device performs a predetermined space frequency characteristic conversion process to an output result of the conversion process device. A halftone processing device performs a quasi-gradation processing to an output result of the second filtering process device.

Abstract: An image processing method of quantizing multi-tone image data by an error diffusion method, includes the steps of a) detecting change of the image data; and b) oscillating cyclically in image space a threshold for the quantization in an oscillation range controlled according to the detection result of the step a).

Abstract: A method for color correcting an original halftone bitmap image by a predefined color correction function to produce a color corrected halftone bitmap image comprising: providing an original halftone bitmap image; estimating the dot area percentage of the original halftone bitmap image in a set of sub-image blocks; calculating an aim dot area percentage, based on a predefined color correction function, for each sub-image block in the original halftone bitmap image, calculating the number of halftone bitmap image pixels to convert to on or off states to produce a modified original halftone bitmap image that has the aim dot area percentage where said value is designated by N, for each sub-image block in the original halftone bitmap image, and converting N pixels in the original halftone bitmap image to either on or off states depending on whether the aim dot area percentage is greater or less than the dot area percentage of the original halftone bitmap image respectively, for each sub-image block in the origina

Abstract: A maximum color identifying portion 41 identifies a maximum color from coloring material colors used to reproduce a color of a line segment after color conversion into coloring material colors by a character/line color converting portion 31 is applied to the rasterized image signal. A structure deciding portion 42 outputs a screen parameter flag that controls a screen parameter in compliance with the identified maximum color and a drawing direction of the line segment such that the screen process in the maximum color is executed at a screen angle, that is different from the drawing direction of the line segment, in a character/line screen processing portion 35. The character/line screen processing portion 35 applies the screen process to the image in accordance with the screen parameter flag by using the screen parameter at the screen angle that is different from the drawing direction of the line segment. Accordingly, disappearance of the line segment due to the screen process is avoided.

Abstract: Methods are provided for generating a dynamic image mask for improving image detail in a digital image. An electronic representation of an image is scanned. A dynamic image mask is generated from the electronic representation of the image. The dynamic image mask has sharp edges which are representative of rapidly changing boundaries in the original image and blurred regions in less rapidly changing areas. The dynamic image mask can be applied to the electronic representation of the original image to improve image detail by altering the image contrast and the grayscale contrast.

Abstract: A method, apparatus, and product to generate trap areas. One embodiment is a method for generating a trap pixel of a trap area surrounding one or more trapping edges of an image that includes, for each trapping edge in the image, and for each pixel within a predefined area around the trapping edge, comparing the distance of the pixel from the trapping edge according to a distance measure with a provided measure indicative of the distance of the pixel from any edge of the image to determine if said each pixel is closer to the trapping edge than to another edge. The method further includes, if said pixel is closer to said edge than to any edge, setting the pixel as a trap pixel of the trap area, including setting a trap color for the trap pixel.

Abstract: A printhead controller controls printing of a page by at least one printhead. The printhead controller, in use, receives data, in a compressed format relating to the page to be printed, the data including a page description comprising a bi-level black layer and a contone color layer. The printhead controller extracts from the compressed data relating to the bi-level black layer the contone color layer. Memory is provided for temporary storage of the expanded data. A dithering/compositing unit produces a ditherer page from the data temporally stored in the memory and feeds its out put to the printhead.

Abstract: An image processing method of quantizing multi-tone image data by an error diffusion method, includes the steps of a) detecting change of the image data; and b) oscillating cyclically in image space a threshold for the quantization in an oscillation range controlled according to the detection result of the step a).

Abstract: A method for identifying document edges collects a predetermined number scanlines of the document. Both first order and second order statistics are then calculated based on the scanned data. A first slope value being a function of the difference between a plurality of the first value and a second slope value being a function of the difference between a plurality of the second value are calculated. A document edge is detected using the first and second slope values.

Abstract: A method of and apparatus for printing color images by the superimposition of a number of separations, using a first half-tone technique optimized for surface reproduction, such as dithering, and a second half-tone technique, differing from the first and optimized for edge reproduction, such as thresholding with error diffusion, is disclosed. The second half-tone technique is used in edge transitions for pixels of a separation which substantially influences the edge transition, and the first half-tone technique is used outside the edge transition. And the first half-tone technique is used throughout in the case of pixels of a separation which provide no or minimal contribution to the edge transition.

Abstract: An image processing method and an image processing apparatus for generating a binary image by binarizing the pixels of multlvalued tones are disclosed. An intended pixel, at least a pixel adjacent to the intended pixel and the density difference between the intended pixel and the adjacent pixel are determined. In the case where the density difference is larger than a predetermined setting, the intended pixel is determined as an edge portion. The binarization threshold for the intended pixel constituting an edge portion is set lower, the larger the edge intensity with the adjacent pixel. Thus, the edge reproducibility of the binary image after error spreading is improved.

Abstract: A technique is provided for reducing inking of image and text areas in an ink jet printing system. Initially, a shaded image/text multi-bit mask is provided. Half-toning, such as error diffusion, is applied to dither the shaded multi-bit mask to a one-bit mask. An image/text bitmap is loaded before applying a logical AND to the one-bit mask and the bitmap to generate a reduced ink image or text character. A character outline is created from the character bitmap. Finally, a logical OR is applied to the reduced ink character and the character outline to generate a reduced ink character with defined edges. This technique maintains fine detail in the image area as well as fine detail in small text characters.

Abstract: A digital image processing method for adaptively sub-sampling an image to X % of original pixels, includes the steps of generating an edge map of the image; normalizing the edge map to N-bits; applying a shift to the normalized edge map such that X % of the pixels will be ones when the normalized shifted edge map is halftoned using a blue noise halftoning technique; halftoning the edge map using the blue noise halftoning technique to generate a halftone mask; and sub-sampling the image at the pixel locations represented by ones in the halftone mask.

Abstract: In a method for changing the size of line elements on a printed page, first the nature of the size change is determined and a positive/negative identifier identifying the nature (positive/negative) of the line elements is determined for each pixel of the printed page. A copy window whose expanse determines the desired size change is defined around a substitution field. Copy window and substitution field are displaced across the printed page, and the density values of the copy window are compared to the density value of the substitution field in each window position.

Abstract: Methods and apparatus for adaptive halftoning for accommodating a mix of high and low visual activity are provided. Accommodations for white gap reduction and variable darkening are provided for print engine imperfections. A method includes the steps of thresholding a selected pixel of a source image to generate a first dithered output signal, L. The selected pixel is also thresholded to generate a second dithered output signal, S. A weighted combination of the first and second dithered output signals is generated in accordance with at least one of an edge activity indicator parameter and a mix suppression parameter. The parameters are calculated from pixel values within a contiguous region of the source image including the selected pixel. The first and second dithered output signals correspond to large and small threshold matrices in one embodiment. The second dithered output signal may be boosted using a variable darkening parameter, &ggr;, to accommodate isolated dot gain problems before being combined.

Abstract: A method for enhancing printing quality to process the picture and textual data in an image properly such that both the picture and textual data can be clearly printed. The inventive method can treat the image data to be printed in a real time fashion and while the entire image data is not required. In the inventive method, the difference of gray level is reallocated by error diffusion method to render the edge more smooth and clear.

Abstract: A method and computer-readable medium for applying tonal correction to a binary halftone image formatted in a bit-mapped manner. The binary halftone image is descreened to obtain an individual tonal value for a plurality of pixels representing the binary halftone image. The individual tonal value is compared to a calibrated tonal value to determine a tonal change for each pixel. Based on the tonal change for each pixel, a probability of change is determined for each pixel in a set of pixels out of the plurality of pixels. The probability of change is used to determine which edge pixels undergo a state change (i.e., on to off) to effectuate a desired tonal adjustment of the binary halftone image. Error diffusion may be applied to further distribute the state changes of the edge.

Abstract: In a networked printing environment having at least a number of workstations of users, a management unit maintains logic storage spaces in a memory, each allocated to a respective user. Digital data files sent from a user's workstation for printing contain an identification of the relevant user and are either of a first type or of a second type. The first type is formed by files which must be printed automatically, and the second type is formed by files which must be stored in the logic storage space of the user in the memory and may be printed only on a command from the operator control unit, which command identifies the relevant file. When handling a print job, the management unit checks, whether the job can be performed completely. If this appears not to be the case, the management unit converts the file into a file of the second type and, if necessary, creates a logic storage space for the relevant user and stores the file in the logic storage space of the relevant user.