Patent ID: 7590343
Filing Date: 2009-09-15
Classification: G01S,H04N

Abstract:
1. An autofocus system, comprising: an imaging device which captures a subject image formed by an optical system; a frame operation device that sets an autofocus frame within the captured image, the autofocus frame including an image of a target subject; an image processing device that stores the target subject as a reference pattern image; a matching image detection device which detects an image that most matches the stored reference pattern image from subsequently captured images captured by the imaging device; a determining device that determines that the image of the target subject was detected among the subsequently captured images when a correlation value which indicates a degree of matching of an image detected by the matching image detection device with respect to the reference pattern image is equal to or greater than a predetermined threshold value and determines that an image of the target subject was not detected among the subsequently captured images when the correlation value is less than the threshold value; a changing device which changes the threshold value in the determining device; an autofocus device which, only in a case where the determining device has determined that an image of the target subject was detected, takes a position, on a screen showing captured images, of an image that was detected by the matching image detection device as a position of the target subject to focus on and performs focus adjustment of the optical system such that a target subject in the position is in focus; and an updating device that updates a position of the autofocus frame based on the position of the image.