Patent ID: 6753919
Filing Date: 2004-06-22
Classification: G06K,H04N

Abstract:
A method of assessing the focus of an image, comprising the steps of:convolving the image with a convolution kernel comprising: (a) isolating one portion of a plurality of portions of said image; (b) summing a central group of pixels of said portion to obtain a first sum; (c) summing a plurality of outer pairs of rows and columns outside said central group of pixels to obtain a second sum; (d) combining said first sum and said second sum in a predetermined ratio; and (e) squaring the convolution result; determining a spectral energy of said convolved image comprising: (f) repeating steps (a)-(e) for further portions of said plurality of portions of said image and accumulating each said convolution result to generate a summation representative of said spectral energy; and determining a focus score responsive to said spectral energy, said focus score being indicative of the focus of the image.