| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem in an intrusion detection apparatus for forming range images by means of reflected laser beams that the accuracy of distance measurements decreases when the strength of the reflected beam decreases, leading to the possibility of errors or faults in the detection of intruders. SOLUTION: Based on the beam reflected to a laser pointed to a monitored space, a distance calculating part 16 calculates the measurement of a distance to an object in the monitored space, for every pixel. A reliability data generating part 34 determines the reliability of the distance measurement based on the amount of the reflected beam received. The higher reliability is obtained when the amount of the reflected beam received is larger. For every pixel, a background difference calculating part 22 corrects a distance difference between a background range image and the target range image being monitored, according to the reliability, and extracts pixels varied between the background range image and the target range image based on the fact that the distance difference value after the correction is equal to or greater than a predetermined threshold. An intruder determining part 24 determines whether or not there is an intruding object in the monitored space according to the pixels varied. COPYRIGHT: (C)2007,JPO&INPIT
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