To optimally extract edges of a picture taken by a camera and thereby exactly detects a target.
A target detector for extracting an edge picture from a picture taken by a camera to detect a target based on the edge picture, obtains an exposure control value (Ep) of the camera when extracting the edge picture and a required exposure control value (E0) of the camera for clearly extracting the edge picture about one or each of a plurality of edges contained in the extracted edge picture, obtains an exposure control variable value from the difference between one or each exposure control value (E0) and the exposure control value (Ep), and adds the obtained exposure control variable value to the exposure control value (Ep) to take a new exposure control value.
Jun Tsuruta
Tetsuro Shimada
Shimichi Akihisa
Masaya Nishiyama