Abstract: A system and method which enables the location and orientation of an image to be determined without introducing scanning artifacts into the rendered image. The system utilizes a separate set of sensors on a scanning bar that are sensitive to a wavelength of light outside the range of wavelengths of the typical sensors found on the scanning bar, such as red, green, or blue. Moreover, the system includes a light source which is capable of emitting the wavelength of light that is outside this range of wavelength of light. Thus, whenever the additional set of sensors detect light, the system would determine that the light was due to a scanning artifact, such as a hole, rip, or dog ear in the original document being scanned.

Abstract: A system and method which enables the location and orientation of an image to be determined without introducing scanning artifacts into the rendered image. The system utilizes a separate set of sensors on a scanning bar that are sensitive to a wavelength of light outside the range of wavelengths of the typical sensors found on the scanning bar, such as red, green, or blue. Moreover, the system includes a light source which is capable of emitting the wavelength of light that is outside this range of wavelength of light. Thus, whenever the additional set of sensors detect light, the system would determine that the light was due to a scanning artifact, such as a hole, rip, or dog ear in the original document being scanned.

Abstract: A process eliminates pattern shifting artifacts in a printed image by perturbing a threshold/image signal value relationship when a multi-level grey level is binarized. The process utilizes a programmable multi-level grey signal modifying circuit for modifying the multi-level grey signal by a predetermined value according to its grey level. The modified multi-level grey signal is binarized to a binary pixel signal according to a relationship between the modified multi-level grey signal and a threshold value. The process further generates an error corresponding to the relationship and diffuses the error to neighboring pixels. The multi-level grey signal is modified with either random noise multiplied by a grey level dependent coefficient or by a predetermined value from a checkerboard or vertical line pattern. The value from the pattern is dependent upon the grey level and pixel location of the image data.

Abstract: A process eliminates pattern shifting artifacts in a printed image rendered using a hybrid high addressable error diffusion process by perturbing a threshold/image signal value relationship when a multi-level grey level is binarized. The process utilizes a programmable multi-level grey signal modifying circuit for modifying the multi-level grey signal by a predetermined value according to its grey level. The modified multi-level grey signal is binarized to a binary pixel signal according to a relationship between the modified multi-level grey signal and a threshold value. The process further generates an error corresponding to the relationship and diffuses the error to neighboring pixels. The multi-level grey signal is modified with either random noise multiplied by a grey level dependent coefficient or by a predetermined value from a checkerboard or vertical line pattern. The value from the pattern is dependent upon the grey level and pixel location of the image data.

Abstract: A system and method digitally scans a document using a high reflectance mode and a low reflectance mode. Initially, a platen cover provides a low reflectance background around the document and the scanner scans the low reflectance background and document to determine an edge of the document or to retrieve other image characteristics of the document. Subsequently, the platen cover changes so as to provide a high reflectance background around the document. The scanner then scans the high reflectance background and the document and produces digital image data relating to an image on the document.

Abstract: A printing system for rendering marks on a recording medium receives a multi-level grey scale pixel value representing a pixel having a first resolution. A screening circuit generates a screened multi-level grey scale pixel value equal to (G.sub.L -V.sub.i)+(S.sub.i -Th)*Dmp.sub.vi *Mod.sub.Eff wherein G.sub.L is the maximum grey level value of the pixel, V.sub.i is equal to the multi-level grey scale pixel value of the first resolution, S.sub.i is equal to a screen value corresponding to a position of the pixel, Th is the threshold value, Dmp.sub.vi is a video dependent dampening factor, and Mod.sub.Eff is a modulation multiplication factor. An interpolator converts the screened multi-level grey scale pixel value to a second resolution, the second resolution being higher than the first resolution, and a binarization circuit binarizes the converted multi-level grey scale pixel value so as to output a binary signal and an error value, the error value having a resolution equal to the first resolution.

Abstract: A system and method electronically image process a pixel belonging to a set of digital image data with respect to a membership of the pixel in a plurality of image classes. This process uses classification to determine a membership value for the pixel for each image classes and generates an effect tag for the pixel based on the fuzzy classification determination. The pixel is image processed based on the membership vector of the pixel. The image processing may include screening and filtering. The screening process screens the pixel by generating a screen value according to a position of the pixel in the set of digital image data; generating a screen amplitude weighting value based on the values in the membership vector for the pixel; multiplying the screen value and the screen amplitude weighting value to produce a modified screen value; and adding the modified screen value to the pixel of image data.

Abstract: The present invention is a method and apparatus for generating N-bit per pixel output signals in response to M-bit per pixel image input signals, where M is greater than N. The invention employs a halftone cell threshold memory that stores a single threshold for each cell element. During real-time processing of the video image signals, multiple thresholds are calculated based upon the stored thresholds, and the image signals are compared to the thresholds. The threshold calculation process is simplified by using equally spaced constants and any desired variation from the resulting equally spaced thresholds is accomplished through a remapping of the video image signals using a look-up table. The output of the plurality of comparisons carried out for each halftone cell element is then encoded to produce a digital gray-scale output signal.

Abstract: A method and system implements a redistributive characteristic into an error diffusion process. A grey level value representing a pixel is received. A threshold circuit thresholds the received grey level value and generates an error value as a result of the threshold. A portion of the error value is diffused to adjacent pixels on a next scanline. All the error for a single pixel on the next scanline is accumulated. Since this accumulated error has a greater number of bits than can be stored in a buffer, a portion of the accumulated error is truncated and redistributed to a down stream pixel for inclusion in the downstream pixel's error accumulation process. The grey level value has a first resolution which corresponds to an original input resolution. In a high addressabilty environment, the received grey level value is interpolated to subpixel grey level values before thresholding.

Abstract: A system and method for calibrating a printing system includes a printer and a master test image document printed by the printer. The master test image has three locator symbols and a plurality of test objects, each symbol having a distinct apex. The apexes are non-colinear. A memory prestores image data corresponding to the test objects printed on the master test image document and positional data corresponding to a desired coordinate value for each non-colinear apex. The system also includes a scanner for scanning the master test image document and detects the locator symbols printed on master test image document to generate transition data therefrom. The calibration process determines a coordinate value for each non-colinear apex based on the transition data and generates a transformation matrix based on a difference between the determined coordinate value for each non-colinear apex and the desired coordinate value for each non-colinear apex.

Abstract: A method and system implements a high addressability characteristic into an error diffusion process. A grey level value representing a pixel is received: The grey level value has a first resolution which corresponds to an original input resolution. The grey level value is interpolated to generate subpixel grey level values which correspond to a second resolution. The second resolution is higher than the first resolution and corresponds to the high addressability characteristic. A threshold circuit thresholds the interpolated grey level value and generates an error value as a result of the threshold. The error value has a resolution corresponding to the first resolution. A portion of the error value is diffused to adjacent pixels on a next scanline.

Abstract: A printing system is provided for printing an image on a substrate. The image is represented by a set of words with each word including M bits and being modulated so as to produce a single bit stream. The printing system includes a multi-phase clock generator, responsive to a clock signal with a first clock rate, for producing N phase signals and a data serializer, communicating with the multi-phase clock generator, for receiving the N phase signals and the word set. In operation, the data serializer processes each word of the word set, with the N phase signals, to produce the single bit stream, the single bit stream being outputted at a second clock rate with the second clock rate being greater than the first clock rate. The data serializer communicates with a print engine, the print engine receiving the single bit stream for imaging the image on the substrate.

Abstract: Method and apparatus for providing interpolated image data from original image data represented in terms of pixels, each pixel defined in terms of value and position in an original image, includes an original image input receiving original image data from an original image source; a page memory operatively connected to the input for storing a page of original image received; a source of interpolation parameters indicating: a slow scan initial pixel value Xinit, a fast scan initial pixel value Yinit, a fast scan x offset value FSx, a fast scan y offset value FSy, a slow scan x offset value SSx, and a slow scan y offset value SSy; a bilinear sequencer calculating for each new pixel, from the received parameters a reference pixel within the image, and a pair of interpolation coefficients for interpolating new pixel values; a memory controller retrieving to an interpolation calculator from the page memory a set of original image pixels including the pixel at the reference position, and three other pixels whose po

Abstract: A method and system implements a high addressability characteristic into an error diffusion process. A grey level value representing a pixel is received. The grey level value is interpolated to generate subpixel grey level values which correspond to a second resolution. A threshold circuit thresholds the interpolated grey level value. In parallel to the interpolation circuit and threshold circuit is an error circuit which generates a plurality of possible error values. One of the plurality of possible error values is selected based on the number of subpixels exceeding a threshold value. A portion of the selected error value is then diffused to adjacent pixels on a next scanline.

Abstract: A method and apparatus for controlling the execution of image processing operations carried out on an array of image signals, the specific operations having been identified by a plurality of predefined windows. The windows are divided into a plurality of regions, the boundaries of which correspond to transitions from one window region to another. Each region defines an exclusive region within the array of image signals, and the image processing operations to be applied to the signals within the boundaries of that region. The image processing operations are selected by decoding an effect data word that is assigned to each pixel and which follows the pixel along the image processing path. The bits within the effect data word are not assigned individual significance which allows the effect data word, in most cases, to maintain the same bit length even though additional image processing procedures or modules have been added to the image processing path.

Abstract: A method and apparatus for controlling the execution of image processing operations carried out on an array of image signals, the specific operations having been identified by a plurality of predefined windows. The windows are divided into a plurality of non-overlapping tiles, the boundaries of which correspond to transitions from one window region to another. Each tile therefore defines an exclusive region within the array of image signals, and the image processing operations to be applied to the signals within the boundaries of that region. Tile data is stored in one of two memory banks, thereby enabling bank switching and reprogramming of the device in real-time to permit management of complex window shapes. The apparatus is designed to efficiently manage the identification of tile regions while minimizing the required decoding hardware. The apparatus also provides flexibility of programming resulting in greater efficiency of memory usage.

Abstract: In conjunction with an image segmentation arrangement, in which the image is processed with an image type detection arrangement, the output of which controls an image processing of the image, there is provided a morphological filtering operation, which initially provides a noise removal filter operating on the image detection signal, to remove noise within an area of the image detection signal, and subsequently provides hole filling filter, which bridges small gaps in the image type detection results.

Abstract: A method and apparatus for controlling the execution of image processing operations carried out on an array of image signals, the specific operations having been identified by a plurality of predefined windows. The windows are divided into a plurality of non-overlapping tiles, the boundaries of which correspond to transitions from one window region to another. Each tile therefore defines an exclusive region within the array of image signals, and the image processing operations to be applied to the signals within the boundaries of that region. Tile data is stored in one of two memory banks, thereby enabling bank switching and reprogramming of the device in real-time to permit management of complex window shapes. The apparatus is designed to efficiently manage the identification of tile regions while minimizing the required decoding hardware. The apparatus also provides flexibility of programming resulting in greater efficiency of memory usage.

Abstract: There is provided a method to convert gray level image data from image input terminals, into binary data for high-addressability image output terminals. High addressability output terminals such as printers increase their virtual resolution in the fast scan direction in order to achieve a higher effective printing resolution. For example, one pixel in the slow scan direction divided into eight pixels in the fast scan direction, improves a printer's actual resolution from n spots.times.m spots per unit area to (8 * n) spots.times.m spots per unit area. Gray level input data representing pixel data from image input terminals such as scanners is encoded by either an analog signal or a quantized digital signal with a large number of levels (e.g. 256 levels). Binary output data has pixels with either a value of one or zero or a much smaller number of gray levels compared to digital input signals.

Abstract: An image processing system for altering the size of an image represented by a plurality of input video signals including a controller for producing a scale factor and a scale factor valid signal. The controller also includes a padder which is used to increase the accuracy of the scale factor during the operation of the controller. The signals generated by the controller are passed to an interpolator suitable for producing an output signal as a function of one or more of the input video signals in response to the scale factor and scale factor valid signal.