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Last Post 14 Dec 2017 03:04 AM by  Owen Roberts
WV_FN_HAAR
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anon



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04 Feb 2017 03:41 PM
    I am trying to use HAAR function to decompose an image and the coefficients, I have read the documentation but I didn't yet understood how to use it, how to get the 4 image components after decomposition with HAAR with order 1.

    Vanc



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    10 Oct 2017 02:14 PM
    I am also interested in this. Were you able to figure this out? I am trying to use the WV_CWT with the haar function but even with the documentation I am not able to call it correctly.

    David Starbuck



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    12 Oct 2017 03:12 PM
    I think you call WV_FN_HARR with the desired order and then you use the results with the WV_DWT function. For example:

    res = wv_fn_haar(1,scaling,wavelet,ioff,joff)
    d = dist(64)
    part_wv = wv_dwt(d, wavelet,scaling,ioff,joff, N_LEVELS=3)

    Ben Castellani



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    16 Oct 2017 02:31 PM
    Just another note ....

    The issue is that the Haar wavelet family is of type discrete. WV_CWT is for continuous wavelets only. You will want to use WV_DWT for discrete.

    You need to run WV_FN_HAAR separately first to create your coefficients based on the order you define.
    Then you input all that information into WV_DWT to create wavelet transform. David's code example is what you need, OP


    Does this make sense? For continuous families, you can use WV_CWT directly. For discrete families, you must wave the WV_FN_FAMILYNAME function first, then WV_DWT.

    ============

    Hope this helps.

    P.S. I will look into making this more clear in the IDL Documentation Center.


    Ben Castellani
    IDL Team
    Harris Geospatial Solutions

    David Starbuck



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    16 Oct 2017 03:17 PM
    It appears the WV functions that will not work with WV_CWT are (most likely because of the reasons Ben C. stated in his post):

    WV_FN_COIFLET
    WV_FN_DAUBECHIES
    WV_FN_HAAR
    WV_FN_SYMLET

    -David S.

    Owen Roberts



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    14 Dec 2017 03:04 AM
    I am also interested in this. Using the code above you get an array of the same size as the input , not like with a wv_cwt where you get a complex array with variations in time and also scale. How can I use the haar wavelet to get a scaleogram as you get easily with wv_cwt?
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