Patent ID: 6023056
Filing Date: 2000-02-08
Classification: G02B

Abstract:
A method of determining focus in an image capture system of the type having an image sensor, optics for forming an image of a scene on the image sensor, and an image processor for determining the best focus, comprising the steps of:a) acquiring an image such that the focus of the image changes continuously, line by line, across the image;b) detecting a plurality of edges in the image that are above a predetermined magnitude;c) measuring the sharpness of the detected edges;d) detecting sharpness of the sharpest edge in each line of the image;e) plotting the sharpness of the sharpest edge in each line versus the location of the line in the image;f) fitting a curve to the plot of sharpness versus location; andg) determining the best focus of the imaging system from the peak of the curve fit.