Patents Examined by II Grant
  • Method for high-quality compression of binary text images
    Patent number: 5204756
    Abstract: The invention relates to a method for the compression and decompression of binary test images. The method distinguishes between large low-frequency areas and small high-frequency areas in the original frame. For the low-frequency areas, a scheme for lossy compression is used, whereas for the high-frequency areas, a scheme permitting lossless compression is applied. The compression/decompression process involves five stages; namely prefiltering to remove all black patches (e.g.
    Type: Grant
    Filed: July 30, 1990
    Date of Patent: April 20, 1993
    Assignee: International Business Machines Corporation
    Inventors: Dan S. Chevion, Ehud D. Karnin, Eugeniusz Walach
  • Image processing apparatus
    Patent number: 5200840
    Abstract: An image processing apparatus comprises an image-area discriminating circuit for discriminating the attribute of an image, such as whether it is a character/line image or a dot image or whether or not it is an isolated point noise, and outputting a discrimination result, an enlargement/reduction processing circuit for performing enlargement/reduction processing on an image, and a filtering circuit for controlling the spatial frequency response of an image in accordance of a discrimination signal.
    Type: Grant
    Filed: July 6, 1990
    Date of Patent: April 6, 1993
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yuzo Koike, Hidekazu Sekizawa, Naofumi Yamamoto