| 摘要 |
PURPOSE:To improve the extracting efficiency of a singular point by increasing the extracting frequency of the singular point when a rectangular mask is used. CONSTITUTION:A large mask 6A having a rectangular viewfield of longitudinal A bit and lateral B bit are set on a screen 60 including a shadow picture together with a small mask 6B having a rectangular viewfield of longitudinal (a) bit (a<A) and lateral (b) bit (b<B) which is included within the viewfield of the mask 6A. Then both masks 6A and 6B are scanned in a body in the lateral direction. If a character/picture part 7 having a singular point is detected within the viewfields of the masks in a scanning process, a scan is carried out within the mask to detect the position of a singular point P.
|
