Patents Examined by J. Wu
  • Color image data compressing apparatus
    Patent number: 6266440
    Abstract: A color image data compressing apparatus comprising a color space converting section for receiving RGB data and outputting data for lightness and chromaticity, a plurality of space converting sections each for converting the data from actual space to a coefficient in each specified transform space, a plurality of quantizing sections each for quantizing the coefficient, and a coding section for coding the quantized data, in which the degree of quantization of the coefficient data is changed according to data for lightness.
    Type: Grant
    Filed: November 3, 1998
    Date of Patent: July 24, 2001
    Assignee: Ricoh Company, Ltd.
    Inventor: Shogo Oneda