Abstract: An automatic scanner calibration method and apparatus is disclosed in which a calibrated target, such as a Kodak® gray strip, is attached to a scanning surface of a scanner. The target is thin and has a width or length of platen of a scanner. During a normal scan, the calibration target area can be ignored or scanned depending on user selection. If the strip is scanned, then the resulting information is used to calibrate the scanner automatically. Such calibration is more accurate than an older in time or preset default calibration Another embodiment of the invention actuates a print of a printer calibration target on a printer on a scheduled basis. Thereafter, the user can take the printer calibration target and place it on the scanner and perform a calibration of a scanner/printer system.

Abstract: A general purpose method for text enhancement that is independent of the type of scanner that is used to scan a document or the device printing the document and is tolerant of the artifacts and defects that the scanning process introduces on the text, mainly blurring. A window of size W×W is constructed on a scanned page with the target pixel at the center of the window and the amount of ink in the window is calculated and the number of pixels that are darker than the center pixel is counted. The window is moved along the page and each pixel on the page has a chance to be the center of a window and be allocated ink. The invention reallocates the amount of ink in full quantities of the darkest value. Only the center pixel actually has its ink reallocated. A key principle is to make an attempt to allocate the ink pixel by pixel in the window, where the darkest pixel gets ink, the second darkest gets ink, and so on, until there is no more ink remaining in the bank.

Abstract: A presentation board digitizer system for large boards preferably employs at least three spaced-apart ultrasound receivers assemblies. A current position of an ultrasound transmitter is assigned as a weighted centroid of time of-flight position measurements based on at least two pairs of receiver assemblies. The weighting used varies as a function of the position of the transmitter across the board. A preferred structure of an ultrasound receiver assembly for use in the system employs a pair of ultrasound receivers arranged side-by-side in a line perpendicular to the surface of the presentation board. The receivers are connected so as to generate a total output signal corresponding to the instantaneous sum of the ultrasound signals received at each, such that the receiver assembly is most sensitive to ultrasound signals incident from a plane adjacent to the presentation board.

Abstract: A method embodiment of the invention tests revisions made to printer graphics interpreter software. A test suite of POSTSCRIPT, PCL, or other high-level printer language is input to a production version of a printer's internal interpreter software. A first bit-map is generated by the interpreter that is normally used to control each pixel in the printing of a page. The same test suite is fed to a work-in-progress revision of the printer's internal interpreter software. A second bit-map is generated. The first and second bit-maps are subtracted from one another. A difference bit-map is inspected. If only minor shifts of objects are noted, or if no differences at all are apparent, the work-in-progress revision is accepted as the new production standard. The second bit-map is used to replace the first. Otherwise, the work-in-progress revision of the printers internal interpreter software is reworked to correct the printing interpretation errors it was making.

Abstract: A technique for segmenting an image into text areas and non-text areas in which an image is stored with the following information per pixel: gray scale intensity (4 bits) and an indication of whether the pixel is neutral or color (1 bit). The image, e.g. a scanned RGB image, is converted to 0-15 levels of intensity and has a neutral/color indication bit assigned to each pixel. The technique proceeds in three phases as follows: Tile the image by square blocks, e.g. 6×6 or 8×8 for 600 dpi images, and store information about each block in a buffer; sweep the buffer left to right three tile rows at a time and make a preliminary decision for every tile-block in the middle row; examine the decision made in the previous step in a context block, e.g. a 3×3 block, and make revisions if necessary.

Abstract: A page of an image is divided into several regions. Each of these regions may be compressed according to a different technique according to the kind of data within the region. Compression is used to reduce the memory requirements. Data for each region is available at any time and can be randomly accessed. Display operations may be processed in any order. For each display operation, the region which is affected is uncompressed and processed. As other regions are processed, memory space is made available by compressing data in currently unused regions. By using this kind of representation of a page and method of processing display operations, each region can be represented independently and differently. Because display operations can be processed in any order, regions may be processed by multiple imaging systems functioning in parallel. Additionally, representations of regions on a page can be stored, transmitted, or used in different locations at different times.

Abstract: A method and corresponding system for tracking variations in distance D calculated from time-of-flight measurements of a sequence of pulses of a pressure wave oscillation from a transmitter to a receiver identifies a state of synchronous operation by obtaining at least two time-of-flight measurements derived from successive pressure wave pulse which satisfy given synchronicity criteria. Successive time-of-flight measurements are then monitored to identify a shifted time-of-flight measurement which varies by at least half of the wave period from a predicted time-of-flight value calculated from a number of preceding time-of-flight measurements. A shift factor is then identified corresponding to an integer multiple of the wave period by which the shifted time-of-flight measurement must be corrected to obtain a corrected time-of-flight measurement falling within half of the wave period from the predicted time-of-flight value.

Abstract: A graphic data-acquisition system which employs an active tracking system provides a retrofittable apparatus for converting a substantially planar surface into an electronic data capture device, in which the components of the system are readily retrofittable, at relatively low cost, to a wide variety of otherwise conventional writing-surface structures, such as so-called dry-erase whiteboards. Conventional triangulation techniques are used to track the position and motion of a writer or eraser. An encoding facility associated with the writing implement provides the ability to distinguish whether the writing implement is used for marking or an as erasing implement, as well as determining the nature or character of written line width or eraser swath. A data stream thus generated can be used in a variety of ways, such as for example, to feed information into the memory of a digital computer, and/or to feed information for transmission to remote stations.

Abstract: In variable data printing, a Variable data Job (varJob) is made out of variable data pages (varPages) which are composed by merging pregenerated labels (e.g. color separated compressed rectangular swatches). Labels are applied on any position in the page. All necessary clipping is preferably performed before labels are submitted to the VarJob. Labels are preprocessed as soon as they become available. Presumably many labels are generated once and applied many times, albeit at different positions in the page. A label preprocessor processes labels after their submission to the job by cutting them into swaths and creating auxiliary information for further planning and scheduling purposes. A page planner analyzes the page composition, estimates times and bandwidth requirements, and prepares a page composition descriptor (PCDesc) that specifies the way the page is composed. A page composer takes in a PCDesc and the necessary preprocessed labels and composes the page.

Abstract: One or more lenses are revolved around an axis normal to a flat scan plane to provide a scanning mechanism for exposure onto (or reading off of) a flat plane of a substrate. The data for the image is remapped electronically or in software to compensate for the curved path of the focal point of the scanning lens. Combined with a conventional scanning mechanism in a second axis, an area scan is accomplished inexpensively on a flat plane.

Abstract: Memory storage and memory bandwidth requirements of a color laser printer (or other printer having real-time printing constraints) are reduced by representing image information in a compressed format throughout the rendering process. At any one time during the rendering process, preferably, only a single scan line is expanded to the full, uncompressed format required for eventual printing. The rendered scan line is then recompressed and stored in memory. When all scan lines have been processed and are stored in memory in compressed format, the entire image is then expanded in real time and sent to the printer.

Abstract: A hybrid mixed format document that contains document portions prepared by different format sources, such as both black and white and colored pages, prepared by separately printing the colored pages on a color printer, and the black and white pages on a black and white printer. The two document portions are then put in separate locations within a mixed format finishing device. One of the document portions, for example the black and white document portion, includes a cover sheet that provides encoded information, which tells the finishing device how to merge the two document portions into a complete publication. One advantage of the mixed format finishing device is that those pages that contain only text may be printed on a faster, and less costly black and white printer.

Abstract: Methods and apparatuses for correcting gamut limitations of a color device. A method includes creating a predefined color space for use in gamut correction due to the gamut limitations of the color device, such as a color printer, and producing a set of color data values using the predefined color space. The set of color data values is for use in converting from a first color space (e.g., RGB) to a second color space (e.g., CMYK). A method in another embodiment includes creating a first color separation table, creating a predefined color space, creating a second color separation table for converting values of colors in the predefined color space to values in a colorant space, and creating a composite color separation lookup table by using a plurality of first values from the first color separation table and using a plurality of second values from the second color separation table. The predefined color space is typically based upon a set of redefined chromaticities which are used in a transformation function.

Abstract: A system for automatic margin alignment for digital document processors. An output device is calibrated to graphics software without requiring the user to input offset information. The user need only print out first and second calibration sheets, overlay the first sheet on the second, and scan in the overlaid sheets. Margin marks such as vertical and horizontal lines on the first calibrating sheet signal the location of the respective horizontal and vertical margins. The edge of the first calibration sheet contrasts with the second calibration sheet to enable the scanner to detect the edge. Software calculates the required (x,y) offsets based on the number of scanning pixels between the edge of the first calibration sheet and the margin marks, and the resolution of the scanner. A rotational mis-calibration of the output device may also be calculated.

Abstract: An image descreening process first smoothes the image, where smoothing is accomplished by applying a convolution with a low pass filter (LPF) kernel, which is a parameter to the descreening function. Using the smoothed image, a determination is made for each pixel for which pixels around it participate in the modified filter. For a current pixel, a window is considered having the size of the LPF kernel, with the current pixel at the center. A threshold T1 which is given as a parameter, is used to mark the pixels in the current window. Considering a pixel in the window, if for all color components the difference between this pixel value to the center pixel value is less than T1 in absolute value the pixel is marked with a 1. Otherwise, the pixel is marked with a 0. Finally, an adaptive version of the LPF is applied. If the number of pixels marked with a 1 in the window is less than a third of the kernel size, the original pixel value is restored.

Abstract: A configuration description language system in a computer environment provides a mechanism to develop sets of rules intended to govern computing systems. A custom language is provided that the system designer uses to describe constraints and rules of target systems where a rule describes how a certain set of parameters of a computing system are determined based on an input set of desired characteristics. The desired characteristics pertain to certain tasks that the user wants to apply to such a system. The parameters (or constraints) are based upon system limitations such as memory configuration, processor speed and model number. The system designer creates rule sets using the custom language and compiler. The compiler ensures that the sets are complete and unambiguous and converts the custom language into a binary format that is compact, portable, and suitable for efficient searches, thereby minimizing execution times.

Abstract: A calibration apparatus and method for a color printer that allows a user to calibrate a printer without the use of expensive measuring instruments and prior user training is provided. The calibration process prints out two target layouts. On the first target the user selects the primary inks start and end points (highlights and shadows), and the black ink only input value that generates a 30% gray. The primary inks are the device-dependent colorants, cyan, magenta and yellow. The second target compares the 30% black ink with grays made of a combination of cyan, magenta and yellow inks. The user selects the best match in an iterative process. Using this data, calculations are made of the corrections to the original input signal values for the printer. A look up table is updated with corrected input values to compensate for the printer deviation from its standard behavior.

Abstract: A dithered image compression system that converts a source image into an image that is efficiently compressed and yet preserves the visual image information of the original source image in a computer environment. A preferred embodiment of the invention removes the image data from the source image that are lost during the normal storage and halftoning stages in one step. Each pixel in the source image is compared to the threshold array values. If the value of the source image pixel is less than the corresponding threshold array pixel, then a zero is placed in that position in the dithered image array, otherwise a one is placed in the dithered image array. The dithered image array is then compared with the threshold array, thereby creating a range array where the range of each pixel is determined using the dithered image array values combined with the threshold array values.