摘要:
Image rotation systems and methods optimally rotate high addressability binary images by transforming the high addressability image to a quasi-grayscale image having normal addressability. A degree of low-pass filtering may be used in conjunction with resampling the image in the process of generating the normal addressability image for rotation. The quasi-grayscale image is then rotated. The rotated quasi-grayscale image is then converted back to a high addressability binary image using a high addressability halftoning process. The systems and methods provide a process wherein high addressability binary images are rotated without introducing gray-level contours or pattern artifacts such as moiré. Further, the apparatus and method provide compact rotation of high addressability images. The density and edge integrity of the processed image are maintained without introducing false contours.
摘要:
Image rotation systems and methods optimally rotate high addressability binary images in a compact manner. High addressability bit pixels are clustered to form multi-bit pixels. The multi-bit pixel image is rotated +/−90°. A pixel mapping method is employed that realigns high addressability pixels within each target group of pixels in a manner that maintains edge integrity, maintains density, and does not introduce additional false contours. Information regarding neighboring pixel values is used to determine edge information about a given high addressability target pixel group. The edge information includes an edge slope and edge location of the high addressability target pixel group. Based on the rotation angle and the edge information of the pixel group, the target high addressability pixel group is mapped to a preferred pattern. After mapping to a preferred pattern, the high addressability pixel group is rotated.
摘要:
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.
摘要:
A method and apparatus for the control of darkness/lightness in a digital image rendered by a printing system. The technique preferably employs templates to selectively apply different amounts of darkening (lightening) to borders of structures detected within the image dependent upon the need for darkening (lightening).
摘要:
The present invention is a method and apparatus for compensating for position error inherent in a raster output scanning printing system by adjusting the intensity of image exposure to effect a correction in the output image. The invention is particularly well suited to compensate for position errors arising from a plurality of sources by first summing the errors and then applying a single compensating adjustment to the intensity of individual scan rasters based upon the position error thereof.
摘要:
The present invention is a an apparatus for enhancing the output along edges of discharged area developed regions in a tri-level imaging system employing a pulse width and position modulated signal ROS for exposure. The invention enables the identification and selective alteration of video data used to drive the ROS so as to extend the developed regions by a selected amount and eliminate digitization artifacts present in the image to be printed. The extension of the discharged area developed regions is accomplished by extending the width of, or adding separate, exposure pulses in adjacent areas to enable development within a portion of those regions.
摘要:
The present invention is a method and apparatus for converting the resolution of bitmap images, and more specifically, to the use of a template matching process to alter the resolution of digital images for printing or similar methods of rendition. The present invention uses statistically generated templates, implemented using look-up tables, to improve document appearance upon output by converting from an original or input spatial resolution to an output spatial resolution that is device dependent, and where there is a non-integer relationship between the input and output resolutions. The resulting image signals may then be utilized to control a scanning beam where the beam varies in intensity and duration according to the pulses used to control it.
摘要:
A single pass highlight color printing system is enabled by utilizing the disparity between the on-time of a printing system and the on-time of an optical image bar. The image bar output is adapted to be separated into two image outputs which expose two separate areas of a photoreceptor. Each exposed area is developed by a toner of a desired color and the developed image, having two colors thereon, is transferred to a copy sheet to form a two-color output copy.
摘要:
A multiple diode laser array used in a ROS scanning system is modified to reduce the effects of undesirable spatial exposure variation at the surface of certain type of layered, semi-transparent photoreceptors. The spatial absorption variation is later manifested as a "plywooding" pattern formed on output prints derived from the exposed photoreceptor. The laser array is modified to form a merged scanning beam at the photoreceptor surface of two or more diode outputs, each output operating at a different wavelength than the other. In one embodiment, a plurality of diodes, each at a different wavelength, are sequentially addressed, and an image of each diode is scanned across the photoreceptor which results in an exposure distribution that would be similar to that formed by an incoherent beam.
摘要:
In an electronic printer which utilizes an image write bar, a control circuit is provided to compensate for the effects of vibration in a rotating photoconductive member, typically a photoreceptor drum. In one embodiment an encoder is positioned so as to detect spatial displacements of indicia affixed to the photoconductor surface, Correction signals are generated and sent to control circuits which adjust the on/off timing of the write bar operation and/or the intensity of the image bar output. This adjustment results in compensation for the effects of photoconductor vibration.