| 摘要 |
PURPOSE:To improve a detection reliability by preparing a detection area within a monitoring area, and providing an external sensor which generates a detection signal other than a picture signal. CONSTITUTION:After the picture signal at the monitoring area obtained by an image pickup device 1 is converted to a digital signal at an A/D converter, luminance data at a present image memory 21 and a reference image memory 22 are subtracted between picture elements at a difference absolute value circuit 23 with an image processing means 2, then being made into an absolute value, and it is binary-coded at a binarization circuit 24, and an image consisting only of the picture element in which a luminance change exceeding over a prescribed threshold value is recognized can be obtained. Next, an abnormality is detected by an abnormality decision means 3, and also, by referring a bit of distance detection information from a distance sensor 51, an abnormality decision is performed. In other words, when an invader appears, a luminane difference is not generated between a background, but, an obvious difference in a distance between the background occurs. Therefore, it is decided as abnormal when a distance difference is present, and as normal when no distance difference is present.
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