%0 Patent
%D 2001
%T Rotation, scale, and translation resilient public watermarking for images using a log-polar fourier transform
%A Bloom,Jeffrey A.
%A Cox,Ingemar J.
%A Miller,Matthew L.
%A M. Wu
%A Lin,Ching-Yung
%A Lui,Yui Man
%E Signafy, Inc.
%X 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...
%8 2001/08/28/
%G eng
%U http://www.google.com/patents?id=v4AIAAAAEBAJ
%N 6282300