what is the compression ratio?? if i compare 'db' compression ratio with my designed filter..is it should be low or high to be efficient?
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Wayne King
on 30 May 2013
The compression ratio in the wavelet domain is usually expressed as the number of wavelet coefficients that are zero divided by the total number of wavelet coefficients.
This means that the closer the ratio is to 1, the better. If for some reason you're taking the log of that the the closer the log is to 0, the better.
You can use wdencmp() to obtain the compression score, the output argument PERF0.
More Answers (1)
Wayne King
on 30 May 2013
No, Unfortunately, the db4 wavelet filters is doing much better than yours.
A compression ratio of 0 means that none of the wavelet coefficients are being set to zero, which means you have no compression. That finding is backed up by the fact that you have retained all the energy. In compression you should not retain all the energy.
On the other hand, with the db4 wavelet filter, you have more than 1/2 the wavelet coefficients being set to zero.
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