Signafy, Inc.

Jeffrey A Bloom

Matthew Lynn Miller

Ingemar J Cox

Min Wu

Ching-Yung Lin

Yui Man Lui

A method for data preparation and watermark insertion. The method includes the step of preparing the data at a first time by manipulating at least one set of the data characteristics for subsequent insertion of a first watermark. In a preferred embodiment of the method of the present invention the method further includes the step of inserting the first watermark by manipulating the set of data characteristics at a second time subsequent to the first time. In still yet another preferred embodiment of the method of the present invention, the method further includes the step of inserting a second watermark at a third time, before, during, or after the first time, by manipulating at least one set of the data characteristics. In a variation of the present invention a method for inserting a watermark into compressed data is provided. The compressed data has sets of data characteristics. The method includes the steps of inserting a watermark by manipulating the set of data characteristics; and optimizing the manipulated data by modifying the compressed data characteristics subject to a set of constraints.

Method for data preparation and watermark insertion

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.

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Plainsboro, NJ, United States of America

Jeffrey A Bloom