Tracking-frame initial-position setting device and method of controlling operation of same

A method of controlling operation of a tracking-frame initial-position setting device for specifying a target image, which is to be tracked, contained in a subject image obtained by imaging a subject continuously, comprising:

• a display unit displaying a subject image obtained by imaging;
• a distance information generating device generating distance information representing distance to a subject contained in an imaging zone or a distance value which is a value corresponding to this distance;
• a tracking target decision device for deciding a target image to be tracked;
• and
• a decision device calculating an amount of high-frequency component per prescribed area in an image portion, which is within the subject image obtained by imaging, representing a subject having a distance value identical with a value of distance to a subject represented by the target image to be tracked decided by said tracking target decision device, and deciding that the position of an area in which the calculated amount of high-frequency component is equal to or greater than a prescribed threshold value or is maximum is the initial position of the tracking frame.