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Two-dimensional code recognition method

  • US 5,616,905 A
  • Filed: 02/16/1995
  • Issued: 04/01/1997
  • Est. Priority Date: 02/24/1994
  • Status: Expired due to Fees
First Claim
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1. A two-dimensional code recognition apparatus comprising:

  • an image reading section for optically reading an image including a rectangular two-dimensional code figure and for converting the read image into image information of a dot matrix form corresponding to coordinates of reading points;

    an image memory section for storing the image information produced by said image reading section;

    an image processing section for extracting a part of the image information stored in said image memory section which corresponds to the two-dimensional code figure, and for detecting two-dimensional code data from the extracted part of the image information;

    wherein said image processing section includes;

    (i) edge point detecting means for detecting edge points forming an outline of the two-dimensional code figure by scanning rows and columns of the image information which are respectively separated by a predetermined number in column and row directions, (ii) straight line approximating means for performing an approximating operation of obtaining straight lines corresponding to the detected edge points by Hough transform and for determining two perpendicularly intersecting straight lines within a result of the Hough transform by a least square approximation, and (iii) specifying means for specifying the part of the image information corresponding to the two-dimensional code figure based on positions of the determined two perpendicularly intersecting straight lines.

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