Patent ID: 7013024

Claim:
A method for detecting a copy of a composite image that includes a first image and a second image that has information embedded in the second image that will change in appearance when the first and second images are scanned or photocopied, comprising the steps of: scanning the first and second images, wherein the information contained in the second image is produced by the steps of: representing the information contained in the second image by a two-dimensional bar code; filtering the two-dimensional bar code with a spread spectrum algorithm that scrambles the information represented by the two-dimensional bar code; splitting the filter bar code into an equal first part and an equal second part, wherein each first part and each second part will contain an upper portion and a lower portion such that the lower portion of the first cart and the upper portion of the second part will be white or empty space; and detecting a change in appearance of the second image that indicates the first and second images were scanned or photocopied.