Application of Wavelet Transform Filtering for Processing Data Signals from Optical Data Storage Devices

Case ID:

Researchers at the James C. Wyant College of Optical Sciences at The University of Arizona have developed methods for processing data signals that significantly improve the capability of optical disc players to recover data from surface-damaged optical discs. The RF data signal from an optical data storage device is processed and filtered via wavelet transformation to reduce high-frequency noise and limit the effect of defects on the disc. The data signal is subsequently reconstructed with an inverse wavelet transform. As a result, the quality of the recovered signal is increased without altering the information contained in the signal. 


Optical media such as compact discs (CDs), digital versatile discs (DVDs), Blu-Ray discs (BDs) and HD-DVDs have flat, smooth and transparent plastic substrates that are manufactured to tight thickness and depth variance tolerances. Optical storage readout devices, such as CD/DVD players, are designed to be insensitive to fingerprints and minor surface scratches, but deeper surface scratches can damage an optical disc to the point where data are not recoverable in commercial players.


  • Reduces loss of data from previously unreadable optical discs
  • Reduces the number of errant frames when processing data signals
  • Provides a higher quality readout signal


  • Readout devices for CD, DVD, BD and HD-DVD optical disc media

Status: issued U.S. patent #7,974,170

Patent Information:
Contact For More Information:
Richard Weite
Senior Licensing Manager, College of Optical Sciences
The University of Arizona
Lead Inventor(s):
Thomas Milster
Swetha Kannan