| 摘要 |
PURPOSE:To obtain a correct approximate equation by judging whether or not each point is located at a straight line from the relative relation of each point in sequence of points representing the contour of a graphic targeted to process. CONSTITUTION:The start point of the contour of the graphic 21 is set as a remarked point (i), and a point (i-n) separated from the remarked point (i) by (n) in a direction opposite to a tracking direction and a point (i+n) separated from the point (i) by (n) in the tracking direction are set, respectively, and a segment connecting both points to the remarked point (i) is set. Thence, an angle formed between both segments is calculated, and relation 0 deg.<=theta<=180 deg. can be obtained assuming the segment with a smaller angle as theta, and both segments comprise the straight line when it is theta=180 deg.. However, the threshold value theta th within the allowable range of theta capable of assuming that both segments comprise the straight line is set in advance within the range of 0 deg.<=thetath<=180 deg.. Therefore, it is judged that both segments comprise no straight line when it is theta <thetath. Thereby, the correct approximate equation can be found. |
