Improvement of accuracy for distance measurement method by using movable CCD

We propose a method that measures a distance by using a camera with a fixed lens and movable CCD. For the image sequence obtained by moving the CCD along the optical axis at constant intervals, we extract some images with a focused small area corresponding to each part in the range of the camera. It is important to select the focused small area, so we propose a method to do this accurately. Our method has the advantage that it is easy to correct the size change by movable CCD. The validity of this method is verified in experimental results.