Target tracking apparatus, image tracking apparatus, methods of controlling operation of same, and digital camera

摘要

A detection area is decided in a case where a target has gone out-of-frame. If a target is being imaged by a camera continuously, it is determined whether the target has gone out-of-frame. If the target has gone out-of-frame, then the magnitude and direction of motion of the camera are detected. If camera motion is large, it can be concluded that the camera user is imaging the target while tracking it. Accordingly, it can be concluded that the target will again be imaged at the center of the imaging zone. An area defined as a region in which the target will be detected is set at the center of the imaging zone. If camera motion is small in a case where the target goes out-of-frame, it can be concluded that the user is waiting for the target to re-enter the imaging zone and therefore the edge of the imaging zone is set as the detection area.

主权项

1. A target tracking apparatus comprising:
a target detecting device for detecting a target, which is to be tracked, within a detection area of a subject image represented by image data which
is obtained by imaging a subject continuously andis displayed on a screen of an imaging device; a detection area updating device, responsive to detection of the target by said target detecting device, for updating the detection area in such a manner that the detected target will occupy the center thereof; a motion detecting device, wherein said motion detecting device is responsive to the target no longer being detected by said target detecting device in one frame and the motion detecting device detects magnitude and direction of motion of the overall subject image in which the target is no longer detected, wherein said motion of the overall subject image in which the target is no longer detected represents a motion of the imaging device; a detection area setting device for setting the detection area in a following frame when the target is no longer being detected by said target detecting device in said one frame, wherein
if the motion of the imaging device detected by said motion detecting device is equal to or greater than a prescribed magnitude, the imaging device is following the moving target, and the detection area setting device then sets the detection area at a central portion of the subject image in said following frame, andif the motion of the imaging device detected by said motion detecting device is less than the prescribed magnitude, the imaging device is not following the moving target, and the detection area setting device then sets the detection area, whose size differs from the size of the detection area set at the central portion, at an edge of the subject image in a direction opposite the direction of motion of the overall subject image which has been detected by said motion detecting device; and a control device for controlling said target detecting device, said detection area updating device, said motion detecting device and said detection area setting device so as to repeat processing for detecting the target, processing for updating the detection area, processing for detecting the magnitude and direction of the motion, and processing for setting the detection area.