About alternatives to Matlab

sturlamolden sturlamolden at yahoo.no
Sat Nov 18 19:57:00 CET 2006


Filip Wasilewski wrote:

> Actually you have not. The algorithm you presented gives completely
> wrong results. Have a look at quick&dirty(TM) implementation bellow.

God grief. I followed the implementation in Ingrid Daubechies' and Wim
Sweldens' original wavelet lifting paper  (J. Fourier Anal. Appl., 4:
247-269, 1998). If you look at the factorized polyphase matrix for D4
(which gives the inverse transform), their implementation of the
lifting steps the original paper is incorrect. That is scary.

A free PDF or PS of the paper is available here:

http://cm.bell-labs.com/who/wim/papers/factor/index.html



Thanks a lot!


Sturla Molden




More information about the Python-list mailing list