Patent Number: 6,307,950

Title: Methods and systems for embedding data in images

Abstract: A method and system for embedding signatures within visual images in bothdigital representation and print or film. A signature is inseparablyembedded within the visible image, the signature persisting through imagetransforms that include resizing as well as conversion to print or filmand back to digital form. Signature points are selected from among thepixels of an original image. The pixel values of the signature points andsurrounding pixels are adjusted by an amount detectable by a digitalscanner. The adjusted signature points form a digital signature which isstored for future identification of subject images derived from the image.In one embodiment, a signature is embedded within an image by locatingrelative extrema in the continuous space of pixel values and selecting thesignature points from among the extrema. Preferably, the signature isredundantly embedded in the image such that any of the redundantrepresentations can be used to identify the signature. Identification of asubject image includes ensuring that the subject image is normalized withrespect to the original image or the signed image. Preferably, thenormalized subject image is compared with the stored digital signature.

Inventors: Powell; Robert D. (Issaquah, WA), Nitzberg; Mark J. (Cambridge, MA)

Assignee:

International Classification:

Expiration Date: 10/23/2013