Method and apparatus for encoding-decoding a digital signal
US5363096A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 21, 1992 |
| Grant date | Nov 8, 1994 |
| Priority date | — |
| Expiry date | Apr 21, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F17/147
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
After a windowing operation h(n) performed by space-time weighting of the samples, a method and an apparatus for encoding-decoding a digital signal comprising a sequence of samples x(n) consists in performing a modified discrete cosine transform of the samples to calculate the even order transformation coefficients: ##EQU1## for k .epsilon.[0, . . . , N/2-1] with YN-k=-Yk-1 The coefficient Y2k are expressed in the form of an invertible complex transformation: ##EQU2## for k=0, . . . , N/4-1 with y'n=x2n.h2n y"n xN-2n-1.hN-2N-1 W4N=cos(2.pi./4N)+j.sin(2.pi./4N) The invertible comples transformation is calculated using an auxiliary calculation equation: ##EQU3## with: zn=(y2n-yN/2-1-2n)+j(yN-1-2n+yN/2+2n) The invention is applicable to encoding and decoding digital audio or video signals.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.