Resources Contact Us Home
System and method of retrieving a watermark within a signal

Image Number 3 for United States Patent #7529941.

A system and method of retrieving a watermark in a watermarked signal are disclosed. The watermarked signal comprises odd and even overlapped blocks where the watermark is contained in the even blocks. The method comprises, for each k-th even block, subtracting the two adjacent odd numbered blocks from the k-th even block of the watermarked signal to retrieve s*.sub.k(n), transforming s*.sub.k(n) into the frequency domain to generate S.sub.k(f), calculating a phase of S.sub.k(f) as .phi.(f) and a phase of S.sub.k(f) as .phi.(f), calculating the difference .PSI.(f) between .phi.(f) and .phi.(f), unwrapping .PSI.(f) to obtain the phase modulation {tilde over (.phi.)}.sub.k(f), and using a Viterbi search to retrieve the watermark embedded in {tilde over (.PHI.)}.sub.k(f).

  Recently Added Patents
Blue box
Reception system including a mechanism countering pulsed interference
Post-processing including median filtering of noise suppression gains
Apparatus and method for weighing an item of mail during transport through a sorting installation and having an anti-vibration device
Terminal for flat test probe
Method of requesting CQI reports
Light irradiation element, image forming structure, and image forming apparatus
  Randomly Featured Patents
Test device and method for testing foam material
Aluminosilicate coating method, coated articles and organic substituted silicon-oxygen-aluminum oligomers
Circuit for storing the amplitude of the lower-frequency portion of a composite signal
Predicting energy consumption
Motor fuel composition
Nonvolatile semiconductor storage device
Etching method and etching apparatus
Machine for developing photographic material
Chimeric oligonucleotides for modulating gene expression