DocumentCode :
1276427
Title :
Factorization of the coefficient variance matrix in orthogonal transforms
Author :
Akansu, Ali N. ; Haddad, Richard A.
Author_Institution :
Dept. of Electr. & Comput. Eng., New Jersey Inst. of Technol., Newark, NJ, USA
Volume :
39
Issue :
3
fYear :
1991
fDate :
3/1/1991 12:00:00 AM
Firstpage :
714
Lastpage :
718
Abstract :
The authors derive a matrix factorization of the coefficient variances for any fixed transformation. This factorization formulation provides a better framework for understanding the role of transform on the one hand, and the signal source model on the other. It also greatly simplifies the number of computational operations required for each variance calculation. A transform-specific matrix which links the transform to the signal correlation model is derived. This factorization provides a conceptual framework for understanding the behaviour of the transform for different source models. It also significantly simplifies the calculation of the variance of each transform coefficient from a quadruple sum over four indices to a double sum over two indices. This simplification can be used in adaptive transform coding which requires an estimate of the variances. Test results demonstrate that this mode-based variance calculation provides an accurate basis for adaptive transform coding, particularly at low bit rates
Keywords :
encoding; matrix algebra; picture processing; transforms; adaptive transform coding; coefficient variance matrix; image coding; matrix factorization; orthogonal transforms; signal correlation model; transform-specific matrix; Bit rate; Covariance matrix; Decorrelation; Discrete cosine transforms; Discrete transforms; Image coding; Signal processing algorithms; Speech coding; Testing; Transform coding;
fLanguage :
English
Journal_Title :
Signal Processing, IEEE Transactions on
Publisher :
ieee
ISSN :
1053-587X
Type :
jour
DOI :
10.1109/78.80889
Filename :
80889
Link To Document :
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