| 摘要 |
PURPOSE:To remove branch noises and to speed up a processing by extracting a black picture element group on the outer periphery of a tracking frame in a specific shape which has sampling points internally, and expanding the tracking frame until two black picture element groups are obtained and extracting the sampling points. CONSTITUTION:An optional point i(x1, y1) in the chart of a graphic form is regarded as a sampling point to detect a dotted pattern on the outer periphery of the square tracking frame which includes the point i(x1, y1) internally, and a black picture element group present among the white picture elements of the detected pattern is extracted. When there are two extracted picture element groups, a group having longer distance to a last sampling point is selected. When the number of extracted picture element groups is not two, the size of the tracking frame is increased until two black picture element groups are obtained, and the black picture element groups on the outer periphery of the tracking frame are extracted. The two black picture element groups in the tracking frame before the expansion are selected based on the two detected black picture element groups and a group having longer distance to a last sampling point is extracted as a new sampling point. |
