PURPOSE: To calculate a proper thresholding level by making a center area of an object coincident with an object at all times in the method and the circuit for calculating a thresholding level used for an object tracking device.
CONSTITUTION: Received processing area setting information is used to set respectively a processing area including an object, a center area of the processing area and a peripheral area of the processing area on a screen and a luminance level mean value of a displayed video image in the center area and the peripheral area is respectively calculated and the calculated luminance level mean value is used to calculate a thresholding level. In the thresholding level calculation method as above, a picture element position having a maximum luminance level is detected among all picture element luminance levels in the processing area including an object set on the screen and the processing area is set again so that the center area is made coincident with the detected picture element position.
NISHIUCHI HIDEKAZU
SHIBUYA HIROYUKI
