Method and apparatus for selectively reducing noise in a digital signal
US8443025B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 8, 2008 |
| Grant date | May 14, 2013 |
| Priority date | — |
| Expiry date | Sep 12, 2030 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T2207/20064
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Wavelet thresholding using discrete wavelet transforms is a sophisticated and effective approach for noise reduction. However, usage of integer arithmetic implies that not the full range of input values can be used. A method for selectively reducing noise in a digital signal having a first range of values comprises steps of decomposing the digital signal to a plurality of frequency sub-bands, wherein before, during or after the decomposing the digital signal or at least one sub-band is expanded by one or more bits to a second range of integer values, removing in at least one of the frequency sub-bands values that are below a threshold, re-combining the frequency sub-bands, after removing said values that are below a threshold, into an expanded output signal, and de-expanding the expanded output signal, wherein a signal having the first range of values is obtained.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.