Filter banks for enhancing signals using oversampled subband transforms
US8620979B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Dec 26, 2007 |
| Grant date | Dec 31, 2013 |
| Priority date | — |
| Expiry date | Jun 30, 2030 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H2222/06
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
For subband decomposition of a d-dimensional input signal (S) into a number K of subband components (F1-F4), a filter bank has a filtering module (801) transforming the input signal (S) into 2d components including a low-frequency component (L) and 2d−1 higher-frequency components (F1), The 2d−1 higher-frequency components are oversampled, typically by a factor 2, compared to the low-frequency component. The low-frequency component can be further decomposed by means of another filtering module having a similar structure, and the process can be iterated over any number of scales. The reconstruction filter bank has a symmetric structure, with filtering modules adapted to the oversampling of the higher-frequency components. Such filter banks are well suited to various enhancement processing applied to the subband components such as thresholding, reduction of compression distortion, reduction of measurement noise, sharpness enhancement.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.