Patent ID: 6804356
Filing Date: 2004-10-12
Classification: H04N

Abstract:
A method of creating an authentication signature corresponding to an image, comprising:partitioning at least a portion of an image into a selected number of first-level blocks of image information; determining a first-level block value corresponding to a characteristic of the portion of the image contained in each first-level block; processing the first-level block values for the first-level blocks and generating a first-level signature segment based on the first-level block values as a result of such processing; subdividing each first-level block into a selected number of second-level sub-blocks; determining a second-level sub-block value corresponding to a characteristic of the portion of the image contained in each second-level sub-block; processing the second-level block values for the second-level sub-blocks and generating a second-level signature segment based on the second-level block values as a result of such processing; and combining at least a portion of the second-level signature segment with at least a portion of the first-level signature segment.