| 摘要 |
PURPOSE:To detect a position of a target in high precesion by a method wherein a memory of a limited capacity is effectively utilized to obtain an approximate position of the target from an image pattern of a wide visual field in rough picture element density and after then, an image of a narrow visual field including the target in high picture element density. CONSTITUTION:Commands of a computer 8 make a circuit 5 issue signals H1-H3, V1, V2 and control a timing for an A/D converting operation 6 of an image pick-up unit 3. When the image is extracted covering the whole range of a pattern image A, the good timing is thinned out, and the extraction is made in the low picture element density and partially in the high picture element density according to an extraction characteristic of the converter 6 only in the specific time-zone as the signals V2H2, V3H3. The total number of the picture element for the selective extraction is determined and the pattern image in the wide range is written-in in the low density and the wide range density. An outline of the position in a desired detection-zone is detected from the pattern image in the wide range, and subsequently, the target is position-detected in the high precesion according to the pattern image in the high picture element density and in the narrow range. Thus, since the signals in the broad region are processed in the low picture element density, the device is made simple and speeding up. |
