| 摘要 |
PURPOSE:To detect a projection without requiring a good pattern to be compared and bulky hardware by operating a pattern image and a mask image and extracting a characteristic point to detect the projection. CONSTITUTION:An external mask subtraction circuit 1 receives the input of a binary image signal (h) showing the image of a pattern by '1,0' in a pixel unit and, after '1,0' of the image is reversed to '0,1', the circuit 1 subtracts the image of an external mask M1 to output a subtraction image signal (i). A characteristic point extraction circuit 2 receives the signal (i) to apply thinning processing thereto and detects an end point to output a characteristic point signal (j). In a normal pattern having no projection, no end point is detected. An internal mask confirming circuit 3 receives the signals (j), (h) to set the detected end point as a candidate point showing the projection of the pattern and confirms the genuineness thereof to output a projection detection signal (k). |
