DEVICE AND METHOD FOR DETECTING PARALLEL LINE SEGMENTS AND RECORDING MEDIUM FOR RECORDING PARALLEL LINE SEGMENT DETECTION CONTROL PROGRAM

摘要

PROBLEM TO BE SOLVED: To provide a method which can detect parallel line segments which have a complex waviness or unspecified shape with a simple algorithm. SOLUTION: This device is a parallel line segment detection method for detecting the parallel line segments from a graphic element extracted from an edge picture obtained by differentiating a picked up image and is constituted so that it contains a binarization process (S16) for converting the graphic element to a binary picture of brightness and darkness, a thinning process (S17) for converting the binary picture only to a line segment which has a line width of one pixel, a direction distribution calculation process (S22) for calculating a distribution of a direction element of the line segment constituting each line segment mentioned above and a parallel line segment existence decision process for comparing the distribution of direction element of each line segment above and judges that both line segments are parallel when compared distributions of direction elements are similar to each other.