| 摘要 |
<p>PURPOSE:To evade misinformation due to a single phenomenon and to improve the reliability by sending out a detection signal only when the frequency of continuous moving body detection based upon a brightness difference output exceeds a specific value. CONSTITUTION:The latest digital image signal B is compared with an image A which is stored 4 and a specific time before in picture element units to calculate the gradation difference C (brightness difference output), which is compared with the gradation difference (j) which is the threshold value of the brightness difference to remove picture elements which are less than the gradation difference (j) as brightness variation which is irrelevant to a moving body. Then brightness variation detection outside an area to be monitored is made ineffective by using an optionally set mask area map M and the misinformation is evaded. Then the number En of picture elements which vary in brightness by more than the gradation difference (j) in the area to be monitored is counted 6 and an alarm signal AL is outputted only when the counted number of picture elements exceeds the alarm lower-limit number (k) of picture elements which is its threshold value; and an alarm counter 7 counts the signal AL and sends an alarm for a moving body detection signal when the signal AL is outputted continu ously by more than the number l of continuous times, thereby indicating the detection.</p> |
