Abstract: A color printing process, printing a color image in which out-of-gamut original colors are present. Each pixel is reviewed in context of its neighbors prior to remapping, so that a remapping function may take local area information into account in the remapping process.

Abstract: An improved technique for compressing a color or gray scale pixel map representing a document using an MRC format includes a method of segmenting an original pixel map into two planes, and then compressing the data or each plane in an efficient manner. The image is segmented by separating the image into two portions at the edges. One plane contains image data for the dark sides of the edges, while image data for the bright sides of the edges and the smooth portions of the image are placed on the other plane. This results in improved image compression ratios and enhanced image quality.

Abstract: A method detects if an image is compressed. The method determines a block grid within the image and establishes blocks from the determined grid. The method then computes differences between samples inside the established blocks and differences between samples across the established blocks. The method determines that the image is compressed based on characteristics derived from statistics of the computed differences.

Abstract: A method and apparatus for selecting colors for blocks for use in a Block truncation Coding scheme is disclosed. The method includes finding the largest cluster of pixels and selecting that color for the first color in the block. The average color of the remaining pixels is assigned to the second color. The invention may be applied in iterative fashion if more than two colors are to be assigned to the block.

Abstract: Efficient and uniform heating of a thick transfuse member, wherein the transfuse member is constructed in the form of a transfuse belt that is subject to heating at both front and rear surfaces. An elongated cavity is defined by a portion of the path of the transfuse belt about a plurality of guide rollers. Front surface heating is accomplished by use of a heated roller and rear surface heating is accomplished by use of a heat source situated within the cavity. The majority of the cavity is enclosed by the transfuse member and the guide rollers. Substantially all of the output of the heat source is efficiently transferred to the transfuse member and little or none of the heat produced by the heat source is lost to other components or structures.

Abstract: An improved technique for compressing a color or gray scale pixel map representing a document using an MRC format includes a method of segmenting an original pixel map into two planes, and then compressing the data or each plane in an efficient manner is disclosed. The image is segmented by separating the image into two portions at the edges. One plane contains image data for the dark sides of the edges, while image data for the bright sides of the edges and the smooth portions of the image are placed on the other plane. A thresholding technique and apparatus for generating a bitmap is also disclosed that may be used to accomplish these tasks is also disclosed.

Abstract: An electrostatic recording medium includes a charge retentive layer located on a conductive substrate. An image recording surface on the charge retentive layer includes an array of discrete, conductive segments present in the image recording surface. A multiple electrode assembly having an array of recording electrode tips may be aligned for engagement with the image recording surface. Relative movement between the recording head and the electrostatic recording medium may be provided in such a manner that certain members of the recording electrode tips momentarily achieve Ohmic contact with respective elements of the discrete conductive segments present in the image recording surface. A latent image may be created in the electrostatic recording medium as the charge retentive layer receives an imagewise pattern of localized, discrete charges according to a variable voltage potential present at the tips of the recording electrode during the respective moments of Ohmic contact.

Abstract: A system and method classify a pixel of image data as one of a plurality of image types. A first image characteristic value for the pixel, a second image characteristic value for the pixel, a third image characteristic value for the pixel, and a fourth image characteristic for the pixel is determined. Some of these determinations may be resolution dependent. The values from these determination are utilized in assigning an image type classification to the pixel. An auto-segmentation circuit enables classifying a pixel as a continuous tone and detecting a gradient in the window of pixels of which the pixel is a member. A filter enhances the image data of the pixel tone when a gradient indicating that image data within the window of pixels is changing at a rate greater than a predetermined threshold is detected or lowpasses the image data of the pixel tone when a gradient indicating that image data within the window of pixels is changing at a rate less than a predetermined threshold is detected.

Abstract: A method and apparatus for compressing a mixed raster content image that represents a color or gray scale a document is disclosed. The pixel map is decomposed into a three-plane representation—a reduced-resolution “upper” plane, a reduced-resolution “lower” plane, and a high-resolution binary selector plane. An iterative smoothing technique is then used to pre-process the upper and lower planes using the information contained in the selector plane, thereby reducing the amount of data that will be subjected to further processing.

Abstract: An improved technique for compressing a color or gray scale pixel map representing a document using an MRC format including a method of segmenting an original pixel map into two planes, and then compressing the data or each plane in an efficient manner. The image is segmented such that pixels that compress well under a lossy compression technique are placed on one plane and pixels that must be compressed losslessly are placed on another plane. Lossy compression is then applied to the lossy pixel plane while lossless compression is applied to the lossless pixel plane.

Abstract: In an electrostatic and development control in a printing apparatus, unwanted variation in dot size and shape may be stabilized and the DMA variability under halftone control may be decreased, by use of a novel halftone discharge ratio (HTDRmidtone) along with the conventional actuators of development potential, cleaning potential, and exposure level. A three-input, three-output MIMO control system may be constructed to deliver superior regulation of halftone and solid area image quality with use of control algorithms that are based on the halftone discharge ratio and with use of as few as two developed halftone test patches.

Abstract: An imaging system for effecting electrostatic printing of an image, wherein the imaging system includes at least one contact electrostatic printing engine operable in a novel fashion upon a copy substrate, wherein the contact electrostatic printing engine images and develops an electrostatic latent image representative of the image on an imaging member, and subsequently transfers the developed image from the imaging member to the copy substrate in a direct adhesive transfer step.

Abstract: The present invention is a method and apparatus for automatic image segmentation using template matching filters. The invention generally segments differing binary textures or structures within an input image by passing one or more structures while removing other structures. More particularly, the method and apparatus segment a stored binary image using a template matching filter that is designed to pass therethrough, for example, text regions while removing halftone regions.

Abstract: Imaging system for effecting single pass, multicolor printing of a color image, wherein the imaging system includes a plurality of contact electrostatic printing engines operable in serial fashion upon a copy substrate, wherein each contact electrostatic printing engine images and develops a respective electrostatic latent image representative of a component of the color image, and subsequently transfers the developed component image to the copy substrate as the copy substrate proceeds in a single pass through the imaging system.

Abstract: A processing system for preparing a plural separation document image for printing, including a process for mitigation or reduction of three color moiré. An approximation of moiré amplitude is calculated, and compared to a reference. Where three color moiré mitigation is desirable, black is removed and replaced with other separation colors.

Abstract: An improved technique for processing a color or gray scale pixel map representing a document is disclosed. The pixel map is decomposed into a three-plane representation, a reduced-resolution “upper” plane, a reduced-resolution “lower” plane, and a high-resolution binary selector plane. The “upper” and “lower” planes contain the color or gray scale for the page as well as the continuous tone pictures that are contained on the page. The selector plane stores information for selecting from either the foreground plane or background plane during decompression. Information contained in the selector plane is first used to pre-process the upper and lower planes to reduce the amount of data on each of the other two planes that will be subjected to further processing. Each of the pre-processed planes is compressed using a compression technique optimal for the type of data that resides upon it.

Abstract: An improved technique for processing a color or gray scale pixel map representing a document is disclosed. The pixel map is decomposed into a three-plane representation, a reduced-resolution “upper” plane, a reduced-resolution “lower” plane, and a high-resolution binary selector plane. The “upper” and “lower” planes contain the color or gray scale for the page as well as the continuous tone pictures that are contained on the page. The selector plane stores information for selecting from either the foreground plane or background plane during decompression. Information contained in the selector plane is first used to pre-process the upper and lower planes to reduce the amount of data on each of the other two planes that will be subjected to further processing. Each of the pre-processed planes is compressed using a compression technique optimal for the type of data that resides upon it.

Abstract: A system and method electronically determines an edge of a copy substrate to be printed on. A copy substrate is inserted between a linear light source array and a linear sensor array and a light segment of the linear light source array is illuminated. An edge location of a shadow created by the copy substrate intersecting a light path between the illuminated light segment and the linear sensor array is measured, and a location of the edge of the copy substrate is calculated based on the measured shadow location. A second light segment of the linear light source on an opposite side of an expected copy substrate edge position of the light segment can also be illuminated, and a second edge location of a shadow created by the copy substrate intersecting a light path between the illuminated second light segment and the linear sensor array can be measured wherein this second measurement can be used with the first to calculate a location of the edge of the copy substrate.

Abstract: A method of quantizing pixels from a first pixel depth to a second includes adding to an original value of each pixel to be quantized, an error value resulting from quantization of any previous pixels, to generate a modified pixel value; comparing each modified pixel with threshold varying in accordance with the gray difference that a printed mark would make to a neighborhood pixels and outputting second depth pixels responsive to said comparison; and determining a halftoning error as a function of the modified pixel values, the gray difference, and the binary signals, and distributing say error to other gray level pixels in an image.

Abstract: A method and apparatus for efficiently transmitting digital image data is disclosed. More specifically, the present invention accomplishes fast data transmission by analyzing the content of input data, and then retrieving data that closely matches that which would be produced if the data were subjected to some form of data compression from storage. The retrieved data is transmitted to the retrieving device, thereby eliminating the need for very time consuming data compression processes.