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i've an gray scale image I to be decomposed...i want to extract the low frequency and high frequency component out of it...can anybody help me?

Asked by pammy
on 12 Apr 2013

i want to extract the low frequency component(approximate) LL1 and high frequency component (detail) HH1 at scale one.

can anybody tell me how this is to be done....

reply soon




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1 Answer

Answer by Michael
on 12 Apr 2013

I don't know what LL1 or HH1 are but the 2D discrete Fourier transform should find you the frequency components of the image, in MATLAB it's "fft2".


No answer from any wavelet experts yet. Hmmm... I wonder why you didn't list the wavelet toolbox like I recommended. Did you see the "Products box right underneath your original question? Again, I'm not the wavelet expert.

on 13 Apr 2013

sir i've posted my question second time earlier my question was not answered by anyone about an month ago...the toolbox is the wavelet toolbox... there are many inbulit function on wavelet like discrete wavelet transform it is dwt2,fft2,dct2 and so on but i want the inbuilt function for dyadic wavelet transform

i got two function


but this includes upsamplindg and downsampling...i use Dyadic wavelet transform because it is shift invariant and does not involve downsampling.

nobody is responding on my question.m feeling helpless and in a trouble..

can u tell me the email id of experts who are involve in wavelets?

If you have a support contract, you can call the Mathworks and ask for help from someone such as Wayne King, otherwise you'll have to try in this Answers forum. Search the Answers forum and File Exchange for Wavelet and you'll find lots of people you can contact.

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