1. A control apparatus comprising: an image inputting unit configured to input images from a camera; a region extracting unit configured to extract at least one object region in one of the images inputted by the image inputting unit; a region selection switching unit configured to switch a selected object region among the at least one extracted object region from a first object region to a second object region within the first object region, in a situation where a predetermined key of an operating unit is operated when the first object region has been selected; and a controlling unit configured to perform predetermined controls on the selected object region, wherein said units are implemented at least in part by a computer.