Based On A Local Average, Mean, Or Median Patents (Class 382/272)
  • Patent number: 5654808
    Abstract: A method is described for the rendering of an image on a carrier by a rendering system having a restricted density resolution. A classic screening method for a binary rendering technique is extrapolated to a plurality of energy levels that belong to three classes: non-marking, non-stable and marking stable energy levels. For each class, specific rules must be respected, in order to obtain predictable results without density discontinuities on the carrier. The methods make full use of the spatial and density resolution of the rendering system in areas of high density and increase the reproducibility of low densities by giving up some spatial resolution in the lower density regions.
    Type: Grant
    Filed: July 6, 1994
    Date of Patent: August 5, 1997
    Assignee: AGFA-GEvaert
    Inventors: Marc Herregods, Dirk Broddin, Paul Delabastita
  • Patent number: 5642204
    Abstract: An improved error diffusion method for incorporating into a halftoning algorithm for processing gray scale images to counterpart binary images. The improved error diffusion method adopts a tone scale function to process the input gray scale image before proceeding with the halftoning (error diffusion) processing in order to improve the image darkening problem caused by the conventional error diffusion method and a noise correction process to eliminate the background noises resulted from the accumulated error of the conventional error diffusion method. The proceeding of the tone scaling process and the halftoning process are parallel with the correction process so that errors generated in either one will not affect the other.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: June 24, 1997
    Assignee: Industrial Technology Research Institute
    Inventor: Te-Mei Wang
  • Patent number: 5617484
    Abstract: An image binarizing apparatus, which comprises an image sensor for inputting a character image or a line image, an A/D converter for digitizing the output of the image sensor, a frame memory for temporary storage of the digital image, a window circuit for generating address information for dividing the stored image into a predetermined number of partial images, a brightness extractor for obtaining the highest brightness, lowest brightness and average brightness for the pixels for each block, a neural network which provides the optimum threshold value based on pre-learned data when receiving the highest brightness, lowest brightness and average brightness, a binarizer for binarizing each pixel of a partial image block from the frame memory based on the optimum threshold value ("white pixel" when the value of the brightness of the pixel is larger than the output value of the neural network, and "black pixel" when the value of the brightness of the pixel is smaller than the output value of the neural network), a
    Type: Grant
    Filed: June 6, 1995
    Date of Patent: April 1, 1997
    Assignee: Olympus Optical Co., Ltd.
    Inventors: Toshiaki Wada, Kangda Wang
  • Patent number: 5610999
    Abstract: There is disclosed a method for converting multi-level image data into binary image data and an apparatus therefor. An average density is calculated from the already binarized density of pixels positioned in a predetermined area around an object pixel, and the threshold value for binarization is set by adding a fixed bias value and varying dither signals to the average density, and the error generated in the binarization is distributed to the unbinarized pixels positioned behind. The addition of the fixed bias prevents formation of a spot-free white area in the vicinity of an edge or in the initial stage of processing, and the addition of dither signals prevents texture formation in the low density area.
    Type: Grant
    Filed: June 28, 1994
    Date of Patent: March 11, 1997
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yuichi Bannai, Kunihiro Yamamoto, Hidefumi Osawa
  • Patent number: 5608815
    Abstract: An image testing device captures an image of a test object using a TV camera and raster-scans the image to search the test object for a scratch or spot. The device protects its test precision from being deteriorated by lowered brightness of an illuminator and properly maintains the illuminator by outputting an alarm on detecting a lowering of the illuminator. To realize the capabilities of the image testing device, it comprises a brightness measure circuit, a general determination circuit, etc. The brightness measure circuit receives a multivalued gray image signal or image data from the frame memory through a switching unit, obtains an average value of picture elements in a brightness measure area in a test object image, and outputs it as a measured brightness signal. The general determination circuit corrects, in proportion to a measured brightness a binarization threshold for use in detecting a picture element indicating a defect.
    Type: Grant
    Filed: November 15, 1994
    Date of Patent: March 4, 1997
    Assignee: Fuji Electric Co., Ltd.
    Inventors: Koichi Toyama, Tatsuo Yamamura
  • Patent number: 5606629
    Abstract: In a figure recognition apparatus, a direction of a vector starting from a sample point most recently stored in a position data memory and terminating at an attention point is compared to an average value of directions of sample point vectors stored in the position data memory. The result of the comparison is used for deciding whether to discard the attention point.
    Type: Grant
    Filed: November 15, 1994
    Date of Patent: February 25, 1997
    Assignee: NEC Corporation
    Inventor: Takahisa Shirakawa
  • Patent number: 5578156
    Abstract: A rear surface emission type light emitting diode emits light beams produced at a narrow emanating region out of the rear surface of the substrate. Preferably a device chip should be directly equipped with a lens on the rear surface. A plurality of light emitting devices with a package are laid on an XY-stage which can move in an XY-plane. A camera, a dispenser and a vacuum collet can transfer in Z-direction. The distances and the directions among the camera, the dispenser and the collet are predetermined values. The chip is actually examined by letting it emit light beams from the emanating region. The light is observed by the camera to obtain light power distribution on individual pixels. From the light power, the center of the emanating region is determined. The XY-stage is displaced till the center of the emanating region coincides with the center of the camera. Then the XY-stage is moved by the predetermined distance to send the chip just beneath the dispenser.
    Type: Grant
    Filed: May 27, 1994
    Date of Patent: November 26, 1996
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Mitsutoshi Kamakura, Hiroichi Murakami, Hiroyuki Ishii, Masayuki Nishikawa
  • Patent number: 5577136
    Abstract: There is disclosed an image processing apparatus for intermediate tone processing of an image signal into a binary signal, capable of providing a reproduced image with excellent resolution and gradation with a simple structure, and without the periodic texture inherent to the conventional error dispersing method or average density conserving method. The disclosed apparatus determines the average density of an already binarized predetermined image area, binary digitizing the image signal of a contemplated pixel, utilizing the determined average density as the threshold value, and distributing the error, generated in the binary digitization, to the image data of plural pixels to be digitized thereafter with certain distribution factors. The distribution factors are randomly changed according to random numbers generated by a generator, so that the reproduced image is free from periodic patterns resulting from periodic distributions of the errors.
    Type: Grant
    Filed: June 2, 1995
    Date of Patent: November 19, 1996
    Assignee: Canon Kabushiki Kaisha
    Inventors: Hiroshi Tanioka, Yasuhiro Yamada
  • Patent number: 5566243
    Abstract: A method of inspecting the surfaces of materials to be examined, wherein the surface is scanned line by line by an optical measurement pickup and the signal furnished by the measurement pickup is processed in order to obtain information about the consistency of the surface of the material to be examined, with the picked up lines each being processed in sections in that for each section the average, the maximum and/or the minimum values, as well as an intermediate value, which is representative of the respective section and which is used for further processing, are determined. If the maximum or minimum values lie outside of a given tolerance zone that extends around the average value, the intermediate value equals the maximum or minimum, respectively, otherwise it equals the average value.
    Type: Grant
    Filed: May 23, 1994
    Date of Patent: October 15, 1996
    Assignee: Rheinmetall Sick Optical Inspection Systems GmbH
    Inventors: Wilfried Baller, Karl L. Schinner, Udo Kolb
  • Patent number: 5559610
    Abstract: An image processing apparatus is configured such that an image is photoelectrically read, a reference signal, which follows an output signal from a reading circuit, is formed, whether the level of the output signal is greater or smaller than the level of the reference signal is detected, and a capacitor, for performing a charging operation or a discharging operation in accordance with a result of the detection, is charged during a predetermined time period before the start of the output of the output signal from the reading circuit.
    Type: Grant
    Filed: August 30, 1994
    Date of Patent: September 24, 1996
    Assignee: Canon Kabushiki Kaisha
    Inventor: Kozo Toda
  • Patent number: 5555028
    Abstract: A post-processing filter apparatus for use in an image signal decoding system, capable of improving the image quality of the system, comprises a memory for storing decoded image data of a current frame; a filter for filtering target pixel data in the stored decoded image data to thereby produce filtered target pixel data, wherein the target pixel data represents the value of a pixel to be filtered; a calculator for calculating an absolute difference value between an original target pixel data and the filtered target pixel data; a first circuit for selectively generating a first or a second threshold value based on the decoded image data and the target pixel data; a second circuit for updating the stored target pixel data with the filtered target pixel data if the absolute difference value is smaller than the generated threshold value; and a third circuit for sequentially updating the stored target pixel value with corrected target pixel data T times if the absolute difference value is equal to or larger than
    Type: Grant
    Filed: June 29, 1995
    Date of Patent: September 10, 1996
    Assignee: Daewoo Electronics Co., Ltd.
    Inventor: Sang-Ho Kim
  • Patent number: 5537496
    Abstract: A gradient conversion table is supplied with N-bit input image data and outputs M-bit image data, and a random-number generator outputs K-bit random-number data (M.gtoreq.K). An adder adds the K-bit random-number data to low-order K bits of the M-bit image data outputted from the gradient conversion table, and outputs high-order L bits {L>(M-K)} of the sum as output image data. Low-order bits of the output image data are dispersed to produce an image with any banding of low visibility.
    Type: Grant
    Filed: June 6, 1995
    Date of Patent: July 16, 1996
    Assignee: Fuji Photo Film Co., Ltd.
    Inventor: Takeshi Katayama
  • Patent number: 5524070
    Abstract: In a mail sorting system 10, output pixel intensities of an optical scanner 18 have their contrast locally enhanced. A contrast enhancer 24 uses statistical methods (averaging, standard deviation) coupled with empirical stretch and offset data stored in a ROM 25, to enhance pixel contrast in a pipelined processing operation.
    Type: Grant
    Filed: August 15, 1994
    Date of Patent: June 4, 1996
    Assignee: The Research Foundation of State University of New York
    Inventors: Yong-Chul Shin, Ramalingam Sridhar, Sargur N. Srihari, Victor Demjanenko
  • Patent number: 5506917
    Abstract: In a thresholding method for segmenting gray scale image which is less dependent on the concentration distribution of the input image, the threshold in determined as a zero-cross point of a histogram difference between the concentration histograms for the gray scale image within the window at a window position at which the window contains more high concentration region and at a window position at which the window contains more low concentration region. Also, in a method of determining a background concentration distribution from an image having an arbitrarily distributed pattern, the background concentration level is determined as a peak concentration or a mean value concentration of a low concentration section of the histogram difference of the concentration histograms for two associated windows. Also.
    Type: Grant
    Filed: July 11, 1991
    Date of Patent: April 9, 1996
    Assignee: Nippon Telegraph and Telephone Corporation
    Inventors: Minoru Ito, Toshifumi Watanabe
  • Patent number: 5481628
    Abstract: An adaptive spatial filter for digital image processing selectively performs spatial high pass filtering of an input digital signal to produce an output pixel value having an enhanced signal level using a gain factor that effects a variable degree of enhancement of the input pixel, so that pixels whose activity values are close to an iteratively adjustable activity threshold level will be emphasized significantly less than pixels whose associated activity values are substantially above the threshold level. The activity threshold level is selectively updated at the end of a scan line in accordance with prescribed spatial activity criteria, so as to effectively prevent discontinuities in the threshold level during line-by-line adjustment and to take into account how `noisy` the background is.
    Type: Grant
    Filed: March 9, 1993
    Date of Patent: January 2, 1996
    Assignee: Eastman Kodak Company
    Inventor: Mohsen Ghaderi
  • Patent number: 5454049
    Abstract: In a machine vision system, a pixel-discrimination threshold level, for determining whether pixels are to be assigned one or the other of two values, is established according to parameters obtained in an initialization procedure. During initialization, a test set of items is assembled and data is entered representing indicia appearing on each item of the test set. It is then determined, for each of a range of possible threshold levels, whether the machine vision system correctly recognizes the indicia on the respective test items. Based on the thresholds which permitted correct recognition, threshold parameters are calculated for each test item and average parameters are calculated from the test item parameters. The average parameters are used to set pixel-discrimination thresholds for subsequent recognition operations.
    Type: Grant
    Filed: June 21, 1993
    Date of Patent: September 26, 1995
    Assignee: Sony Electronics, Inc.
    Inventors: Toru Oki, Marcel M. Lissinna