| 摘要 |
PURPOSE:To reduce the missing region of appearance inferiority, in an image pick-up sensor such as an image sensor, by counting a number of picture elements in a mask exceeding a threshold level. CONSTITUTION:A video signal 9 is converted by an A/D converter circuit 3 to be binarized and inputted to brightness comparing circuits 11-1n to be compared with the threshold level from a threshold level generation circuit 2 by a comparator 4 while the output thereof is inputted to an AND circuit 6. The address of each picture element is successively scanned by an address generation circuit 8 and the data are inputted to mask memory 5. A number of picture elements present in a predetermined mask exceeding the threshold value in the AND circuit 6 are counted by a counter 7. If the number of counted picture elements exceed a number of comparing picture elements 11, inferiority is judged. Because a plurality of masks having the same shape,wherein brightness threshold levels and a number of comparing picture elements optimum to said threshold levels were determined and set, a large number of inferiority detection regions are overlapped and inferiority detection capacity can be enhanced. |
