Due to background difference the animal body field selection manner

摘要

PURPOSE: To stably extract a moving object such as a human or a vehicle even in a condition such as outdoors frequently generating variation in illumination or a condition moderately changing a background by executing difference processing between an input image in a required area and a background image to be sequentially updated. ;CONSTITUTION: Monochromatic continuous frame pictures are obtained from a camera 001 and the luminous values of respective small areas a_k are obtained equally to the number of frame pictures during the period of t₀. In a small area a₁, frequency distribution 213 is obtained and the statistic degree of dispersion σ indicates a small value. On the other hand, a moving object is photographed in a small area a₂, so that its luminance value is sharply changed during the period of t₀ and expresses dispersion like frequency distribution 214 and the degree of dispersion σ indicates a large value. Accordingly, the degree of dispersion obtained when illumination is sharply changed, is set up as σ₀, the value σ₀ is compared with the value σ and when the σ is smaller, it is regarded as change in the luminance value due to the variation of illumination and the value of the small area of the background is updated. When the value σ is larger, it is judged as a change in luminance due to a factor such as the appearance of a moving object other than iiiuminance variation and the value of the small area in tlxe background image is not updated.;COPYRIGHT: (C)1995,JPO