The vanishing index, N, controls how many vanishing moments the analyzing and synthesizing wavelets will have. In general, The higher the number of vanishing moments, the sharper the rolloff of the associated high and low pass analyzing and synthesizing filters. However, due to the limitations of the lifting scheme with interpolating wavelets, boundary artifacts become more prevalent for denoising with more vanishing moments. Processing time is also significantly increased for denoising with more vanishing moments. The audio libraries libaudio.a and libaudiofile.a, available in standard releases of the Irix operating system, are required for compilation.
Circular convolution is used to deal with the boundaries.
The program's structure is flexible, however, and the user may easily adopt any set of perfectly reconstructing analysis and resynthesis filters if he wishes to recompile the code. This program can denoise any AIFF file of any AIFF-standard sample rate, number of channels, and sample bitwidth. Written by Corey Cheng, Winter 1996. The input and output files are the filenames of AIFF files of the source and destination files. If the destination file already exists, it is erased and replaced with the output of the denoising process.