Abstract: A method and system compensates for the line width growth or shrinkage in an image rendering system that supports high-addressability. The amount of width adjustment can be a function of the line width. The method is applied after rendering, to the sub-pixel, bit patterns and is compatible with antialiasing and other sub-pixel rendering techniques such as half-bitting. The method and system also require less scan buffering for marker line width compensation than conventional methods. More specifically, the method and system require N+3 scans to detect and adjust widths up to N pixels for leading edges or trailing edges rather than the 2N+3 necessary conventionally. Moreover, the detection and adjustment of widths up to N pixels may be performed for both leading edges and trailing edges using a buffer that can handle 2N+3 scans.

Abstract: A security control system for remote computers includes a first local input/output device for entering a user name and regular password. A password generator (10) returns a single-use password which is an encrypted combination of the user name, a representation of the regular password, and date and time information. A second local input device is used for entering the single-use password. A remote computer (50) receives the single-use password. The remote computer (50) has a cache (76) of previously received single-use passwords. The remote computer (50) compares the single-use password to the cache (76) of previously received single-use passwords. If there is a match further access is denied. Also included is a decryption key (78) which is used to regenerate the user name, the representation of the regular password, and the date and time information. If the date and time is older than a predetermined date and time threshold further access is denied.

Abstract: A method for mapping a color specification to colorant amounts when a first and a second colorant have a similar hue involves the division of portions of color space into regions. Colors of the similar hue are rendered with a first colorant, a second colorant or a blend of the first and second colorants depending on which region of a color specification space the color specification is related. An image processor operative to map color descriptions via the method includes a colorant splitters operative to map a color description to colorant amounts for colorants of similar hue. In a xerographic environment, such an image processor includes a xerographic printer.

Abstract: Image sharpening methods and systems sharpen the edges of objects within images by comparing and replacing the pixel value for a pixel with the median of the original value of the pixel and two values obtained by linear extrapolation of one or more neighboring values on each side of the pixel. By performing the process for all or a plurality of the pixels of a stored image, objects within the image, when output, on a video monitor, paper or other display media, will be provided with sharpened edge characteristics. Thus, the displayed image will include a reduced quantity of edge ringing and a reduced quantity of noise amplification.

Abstract: The present invention provides methods and systems for halftone-algorithm independent calibration of a digital color printer to accurately predict the optical characteristic of color patches printed in the color printer. The present invention is based on 2-by-2 centering patterns where all dots printed are located at intersections of superimposable, virtual grid or coordinate. The present invention provides a further manipulation of the 2-by-2 patterns, which effectively considers the optical scattering in a printing medium. This consideration results in a printer model which possesses higher accuracy in predicting colors of halftone prints.

Abstract: A printing system accurately prints proprietary marks and selected colors. A dictionary of recognizable patterns and defined colors corresponding to the proprietary marks and selected colors is linked to a user interface wherein a user may designate a location within a document and at least one of the proprietary marks with defined colors from an accessible menu. A processor associates the defined colors with the image at the specified location and generates a printer signal representative thereof. Alternatively, the processor includes a pattern recognizer for identifying recognizable patterns within a document. The patterns have a likeness to defined patterns within a pattern dictionary and can be converted to the defined patterns for display or imaging.

Abstract: A method and apparatus to improve the vertical alignment of images captured from video. The method shifts a current scanline by an alignment offset detected locally between either the two fields of the image or within a field of the image itself. This aligns the current scanline to more closely correspond with adjacent intra-field or inter-field scanlines, thereby reducing wiggles or jitters in the vertical lines of the image.

Abstract: Method and apparatus for controlling consumable use in an image-rendering device. More particularly, the invention relates to a image-rendering device that facilitates the limitation of page costs of color documents by establishing a threshold cost limitation and controlling one or more colorant amounts to be used on the page to ensure that the cost limitation is met. An optional override mode may be provided, wherein a selected page or pages, or a complete document, would be rendered without implementation of the cost reduction feature.

Abstract: This invention relates to a method and apparatus for controlling page cost in an image rendering device. More particularly, the invention relates to a system and technique that facilitates the limitations of page costs of color documents by establishing a threshold cost limitation and controlling the colorant amounts to be used on the page to ensure that the cost limitation is met.

Abstract: A method and apparatus selectively displays a processor generated image in accordance with user instructions detected by a processor from a processor viewing device disposed to view a real reference item controlled by the user. The real item, preferably a page of paper, is disposed as a reference frame for an electronic image to be displayed. The orientation of the page is identified by the system. A sensing device, such as a video camera, identifies the position of the page. A display device, goggles, displays the image as a virtual display upon the page wherein the image is transformed in accordance with the identified positioning of the page. The user interaction with the displayed image as detected by the video camera manipulates the page, the contents thereon or can execute hyperlinks to other documents or sites.

Abstract: A printhead uses large and small drop ejectors to achieve efficient gray scale printing. The printhead is arranged with a close packed configuration of alternating large and small nozzles positioned to maximize coverage while minimizing the volume of ejected ink. The printhead may be operated in a single pass mode or dual pass mode. In the single pass mode, complete coverage is effected by rippling through the odd numbered jets first and then rippling through the even numbered jets. The position of the small spots from the even numbered jets can be adjusted to maximize coverage and counteract offset between nozzle centers. Printheads with different size nozzles can also be operated by a staggered firing method using dual passes to offset spots in the scan direction by shifting the printhead between passes or alternating between groups of large and small nozzles.

Abstract: A method and apparatus are disclosed for locating and coloring true boundaries of image elements forming a color image defined with colors having one or more color separations. Once a boundary of an image element is located and determined to be a true boundary of the color image, the original color of the image element boundary is mapped to a solid color so that ragged edges created when rendering certain colors are minimized when reproducing. the color image element.

Abstract: This invention relates to a color calibration alarm apparatus and method for use in an image-rendering device. The alarm apparatus, and associated method, make use of a sensor device that compares printed or measured color values with expected or ideal color values. With the measured values differ sufficiently from the ideal color values, the alarm apparatus signals to the user that a calibration should be performed. The printed or measured color values are obtained from a test patch that is printed, preferably, on a break page between print jobs. The alarm device is placed at the output tray of an image rendering device in one embodiment that may also be a separate stand alone hand-held unit in other embodiments where it is manually used.

Abstract: A printhead uses large and small drop ejectors to achieve efficient gray scale printing. The printhead is arranged with a close packed configuration of alternating large and small nozzles positioned to maximize coverage while minimizing the volume of ejected ink. The printhead may be operated in a single pass mode or dual pass mode. In the single pass mode, complete coverage is effected by rippling through the odd numbered jets first and then rippling through the even numbered jets. The position of the small spots from the even numbered jets can be adjusted to maximize coverage and counteract offset between nozzle centers. Printheads with different size nozzles can also be operated by a staggered firing method using dual passes to offset spots in the scan direction by shifting the printhead between passes or alternating between groups of large and small nozzles.

Abstract: A method for mapping highlight colors to monochromatic textures is provided. It includes reading an input highlight color having a highlight color amount and a base color amount. The highlight color amount is measured and the base color amount is measured. A halftone cell (50) is defined having a plurality of output regions with corresponding output states. The output states of all the output regions are controlled in response to the measured base color amount. The output state of at least one but less than all the output regions is controlled in response to the measured highlight color amount such that the output state of at least one but less than all of the output regions is controlled by both the measured base color amount and the measured highlight color amount.

Abstract: A method for making continuous-tone, raster color images that are less susceptible to the effects of misregistration is described. For each pixel the present method determines the component-wise maximum positive color difference for the pixel from its neighbors. A fraction of this difference is then determined and then added to each pixel's color value, thus eliminating annoying white space between color transitioning in pixels. The particular fractional value is a function of the pixel's luminance.

Abstract: Mapping of full color images to two-highlight color images which provides excellent results for both pictorial image and presentation graphics applications is described. Shades and tints for each hue in the original full color image are mapped to a corresponding triangle of colors in a tetrahedral of possible colors defined by the two highlight colors. The apex of the triangle of colors is varied within the tetrahedral of possible colors according to hue. Differentiations in the result colors for the fully saturated cases is provided while preserving the relative saturation and lightness behavior. The triangle of colors maps to a first triangle bordering one side of the tetrahedral, the first triangle corresponding to a first one of the highlight colors or a second triangle bordering another side of the tetrahedral, the second triangle corresponding to a second one of the highlight colors when the hue of the original colors matches one of the highlight hues.

Abstract: A document containing colored strokes or lines is reproduced in a way to preserve the color intent if the reproduced document is copied on a black-and-white device. Dashed lines are generated for insertion into the stroke, with dashing patterns that reflect the original color of the stroke. Outlining in black or white, dependent on the stroke color, may be provided. If the stroke is wide enough, the color within the stroke may alternatively be reproduced with a black and white reproducible pattern.

Abstract: A method and apparatus for continuously upgrading the color calibration for an electrophotographic printer using a color transform look up table stored in memory. A single or small number of color patch samples are printed at regular intervals during the use of the printing machine. The color patches are sensed and a determination made as to the difference between the sensed color and the desired color. A corrective color calibration value is determined for the sensed patch and a correction is made for that color in the printer memory. The process is repeated to assure that all of the colors within the gamut of the machine are continuously updated.

Abstract: A document containing colored text is reproduced in a way to preserve the color intent if the reproduced document is copied on a black-and-white device. For small text, the fact that it is colored, is conveyed by reproducing it bold, and for medium size text, by reproducing it outlined. For large text, both the fact that it is colored and the color used can be conveyed by filling the interior of the characters with patterns that correspond directly to the color.