PURPOSE: To record only a required picture, to improve recording efficiency and retrieval collation ability and to record the picture of high picture quality by deciding possibility to record the photographed picture corresponding to the result of comparison between the photographed picture and a standard picture.

CONSTITUTION: The input picture photographed by a photographing device 1 is compared 5 with the standard picture, which is recorded to a file 3 in advance, and corresponding to whether the both pictures are coincident or not, the possibility to record the input picture is determined. Thus, without missing only a required still picture, a recording medium is economized and picture data can be efficiently and automatically stored into the file without human labor. Further, retrieval collation speed can be accelerated as well. Objects 10 such as entering persons, etc., near a gate are photographed and the obtained input picture is compared with the standard picture. When the both pictures are coincident, the gate is opened/closed. Then, the identity of the object can be correctly confirmed.