The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 08, 1994
Filed:
Apr. 21, 1992
Pierre Duhamel, Issy les Moulineaux, FR;
Yannick Mahieux, Begard, FR;
France Telecom, Paris, FR;
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.