Patents by Inventor Frank Thomson Leighton

Frank Thomson Leighton has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5664018
    Abstract: A watermarking procedure wherein each of a set of copies of the work has a slightly-modified form of a "baseline" watermark that is placed within a critical region of the data. The slight variations in the watermarks, however, are not perceptually visible and do not interfere with the work. If multiple persons collude to attempt to create an "illicit" copy of the work (i.e., a copy without a watermark), however, at least one of the modified watermarks is present in the copy, thereby identifying both the illicit copy and the copier.
    Type: Grant
    Filed: March 12, 1996
    Date of Patent: September 2, 1997
    Inventor: Frank Thomson Leighton