Patent ID: 7127106

Claim:
A method for fingerprinting an image comprising the steps of: a. transforming said image to a gradient image; b. while the resolution of said gradient image is greater than a predetermined final resolution, iteratively: i. detecting features in said gradient image; ii. creating a set of selected features from said detected features using a predetermined selection algorithm; iii. associating said set of selected features with the current resolution gradient image; iv. saving said set of selected features and said associated current resolution as a resolution specific image feature set; and v. decreasing the resolution of said gradient image; c. comparing said sets of saved selected features in at least one of said resolution specific image feature sets; d. assigning weights to said selected features in said resolution specific image feature sets using a predetermined weight setting algorithm; and e. sorting said selected feature points in said resolution specific image feature sets; wherein said resolution specific image feature sets now comprise a fingerprint for said fingerprinted image.