Constrained wavelet packet for tree-structured video coders
US6625217B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 15, 1999 |
| Grant date | Sep 23, 2003 |
| Priority date | — |
| Expiry date | Oct 15, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/645
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method for optimizing a wavelet packet structure for subsequent tree-structured coding which preserves coherent spatial relationships between parent coefficients and their respective four offspring at each step. A valid frequency tree is defined by a wavelet packet decomposition algorithm. Constraints are placed on the pruning of the frequency tree in order to select valid frequency trees as each step. These constraints include considering any four offspring sub-bands as candidates for pruning only when their current frequency decomposition level is the same as that of their respective spatially co-located parent sub-band, and pruning the spatially co-located offspring sub-bands when pruning only the parents results in an invalid wavelet packet structure.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.