Min Wu

US Patent:

6456726, Sep 24, 2002

Filed:

Oct 26, 1999

Appl. No.:

09/427321

Inventors:

Hong Heather Yu - Plainsboro NJ
Min Wu - Princeton NJ
Xin Li - Princeton NJ
Alexander D. Gelman - Brooklyn NY

Assignee:

Matsushita Electric Industrial Co., Ltd. - Osaka

International Classification:

G06K 900

US Classification:

382100, 713176, 348463

Abstract:

A data hiding system and method for providing a method of embedding multiple layers of hidden data into multimedia data. First, a media unit of the multimedia data is evaluated to determine an appropriate embedding procedure. Next during a first embedding pass, a ruling layer of primary hidden data is embedded into the media unit. In another embedding pass, a governing layer of secondary hidden data is embedded on top of the ruling layer. The secondary hidden data provides control information for controlling the primary hidden data and the host data. Control information such as error correction data, synchronization data, decoding data, and authentication data is embedded in the governing layer. Embedding schemes such as base domain and spectrum domain embedding are employed.

US Patent:

62823000, Aug 28, 2001

Filed:

Jan 21, 2000

Appl. No.:

9/489752

Inventors:

Jeffrey A. Bloom - Plainsboro NJ
Ingemar J. Cox - Lawrenceville NJ
Matthew L. Miller - Princeton NJ
Min Wu - Princeton NJ
Ching-Yung Lin - New York NY
Yui Man Lui - Middle Island NY

Assignee:

Signafy, Inc. - Princeton NJ

International Classification:

H04K 100

US Classification:

382100

Abstract:

A method for detecting a watermark signal in digital image data. The detecting method includes the steps of: computing a log-polar Fourier transform of the image data to obtain a log-polar Fourier spectrum; projecting the log-polar Fourier spectrum down to a lower dimensional space to obtain an extracted signal; comparing the extracted signal to a target watermark signal; and declaring the presence or absence of the target watermark signal in the image data based on the comparison. Also provided is a method for inserting a watermark signal in digital image data to obtain a watermarked image. The inserting method includes the steps of: computing a log-polar Fourier transform of the image data to obtain a log-polar Fourier spectrum; projecting the log-polar Fourier spectrum down to a lower dimensional space to obtain an extracted signal; modifying the extracted signal such that it is similar to a target watermark; performing a one-to-many mapping of the modified signal back to log-polar Fourier transform space to obtain a set of watermarked coefficients; and performing an inverse log-polar Fourier transform on the set of watermarked coefficients to obtain a watermarked image.

Author:

Min Wu

ISBN #:

0387954260