Publisher's Synopsis
Provided is a technique for, even when the lightness of an image contained in a video changes, accurately separating the background of the image and an object in the background and thus efficiently collecting images that contain a target object to be detected, and also suppressing the amount of data communicated between a terminal device and a server. In the present invention, a terminal device accurately separates the background of an image and an object (i.e., a target object to be detected) in the background so as to simply detect the object in the background, and transfers to a server only candidate images that contain the detected object. Meanwhile, as such simple target object detection may partially involve erroneous detection, the server closely examines the candidate images to identify the target object to be detected, and thus recognizes the object.