Efficient coding of digital media spectral data using wide-sense perceptual similarity
US7460990B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 29, 2004 |
| Grant date | Dec 2, 2008 |
| Priority date | — |
| Expiry date | Dec 15, 2026 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG10L19/0204
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Traditional audio encoders may conserve coding bit-rate by encoding fewer than all spectral coefficients, which can produce a blurry low-pass sound in the reconstruction. An audio encoder using wide-sense perceptual similarity improves the quality by encoding a perceptually similar version of the omitted spectral coefficients, represented as a scaled version of already coded spectrum. The omitted spectral coefficients are divided into a number of sub-bands. The sub-bands are encoded as two parameters: a scale factor, which may represent the energy in the band; and a shape parameter, which may represent a shape of the band. The shape parameter may be in the form of a motion vector pointing to a portion of the already coded spectrum, an index to a spectral shape in a fixed code-book, or a random noise vector. The encoding thus efficiently represents a scaled version of a similarly shaped portion of spectrum to be copied at decoding.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.