Method and device for selecting transform matrices for down-sampling DCT image using learning with forgetting algorithm
US7995850B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 4, 2008 |
| Grant date | Aug 9, 2011 |
| Priority date | — |
| Expiry date | Mar 29, 2030 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/60
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Down-sampling of an image may be performed in the DCT domain. A multiple layered network is used to select transform matrices for down-sampling a DCT image of size M×N to a DCT image of size I×J. A spatial domain down-sampling method is selected and applied to the DCT image to produce a down-sampled DCT reference image. A learning with forgetting algorithm is used to apply a decay to the elements of the transform matrix and select a transform matrices which solve an optimization problem. The optimization problem is a function of the visual quality of images obtained using the transform matrices and the computational complexity associated with using the transform matrices. The visual quality is a measure of the difference between the down-sampled DCT image obtained using the transform matrices and the visual quality of the DCT reference image obtained using a spatial domain down-sampling method.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.