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?

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

Answer 1

[Michael]

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".

[Image Analyst]

LowLow, and HighHigh. Wavelet terminology. Sounds a lot like she's using the wavelet toolbox, though she didn't mention it. Pammy, if this is a wavelet question, please list the Wavelet Toolbox in the Products list above. I know Wayne looks for posts labeled like that.

[pammy]

sir m using the wavelet toolbox.

i've to use the dyadic(undecimated) wavelet transform (DyWT).like dwt2 decompose the image into 2 parts low frequency and high frequency

[LL,HH]=dwt2(image,'haar');

but i want to use dyadic wavelet transform as it does not involve downsampling whereas DWT involves downsampling..and also DyWT is shift invariant....

i've read the tutorial there i found

   dyaddown(image);  %for downsampling the image
   dyadup(image);    % for upsampling the image

can u tell me how this is to be done as i've to divide my input image into approximation(low pass) and detail (high pass) part using Dyadic Wavelet Transform

[pammy]

plz help me

[Image Analyst]

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.

[pammy]

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

   dyaddown(inputImage);
  dyadup(inputImage);

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?

[Image Analyst]

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.