Method and apparatus for evaluating defocus in an image of a scene

Abstract

A method of evaluating defocus in an image of a scene comprising; applying first modulation to incident light front the scene to generate a first image of the scene; applying second modulation to incident light from the scene to generate a second image of the scene; calculating first recovered image data from the first image using a first recovery kernel corresponding to the first modulation and specified defocus data; calculating second recovered image data from the second image using a second recovery kernel corresponding to the second modulation and specified, defocus data; and calculating defocus data based on comparison of the first recovered image data and the second recovered image data.