Does NI offer 3D deconvolution?
in [LabView]
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From: Bassett Hound on 20 Sep 2006 13:10 Hi Don, LabVIEW still only supports 2D convolution in 8.2. I would imagine that there should be a way to get from 2D to 3D as I found several sites (after a google search) regarding this. However I have not tried this out. Regards, Steve
From: DonRoth on 20 Sep 2006 16:10 Remember we are talking DEconvolution here, not convolution. In fact, there is no canned fx that I can find in LabVIEW 8.2 even for 2D deconvolution. You need to perform 2D FFTs on your inputs, divide them, and then do a 2D inverse FFT. I accomplished it using Vision 2D FFT functions (which I include as screenshot here). It is surprising to me that LabVIEW has the 2D convolution but not 2D deconvolution. Additionally, my experience with the 1D deconvolution function yielded a single scalar value (I expected a 1D array because that was the format for my inputs), so I used the FFT/Division/Inverse FFT strategy here as well. It is actually a good sanity check for me to post this here I still have some questions regarding 1D (waveform) deconvolution in terms of the final result. Reconvolving the result with the reference approximately gives the original response with some artifacts likely due to the math - but overall it looks correct. Sincerely, Don 2D deconvolution.png: http://forums.ni.com/attachments/ni/170/206494/1/2D deconvolution.png 1d deconvolution.vi: http://forums.ni.com/attachments/ni/170/206494/2/1d deconvolution.vi
From: DonRoth on 21 Sep 2006 12:10 I'll have to get more details for you on how the PSF for the (in this case, pulsed terahertz) system was physically obtained. I was sent the data to process. It is an impulse response function to the THz stimulation. I am attaching the tab-delimited text file here which you can plot in excel using one of the surface graph modes. Viewing it in 3D allows you to clearly see the center peak above the lower background. Don PSF3.dat.txt: http://forums.ni.com/attachments/ni/170/206673/1/PSF3.dat.txt
From: chilly charly on 5 Oct 2006 11:40 This is my attempt to deconvolute a blurred image. Since it does not give the expected result, I guess there is something wrong. :) Could some Fourrier transform expert give a look at the diagram and put me back on track please ? Deconvolution.zip: http://forums.ni.com/attachments/ni/170/208827/1/Deconvolution.zip
From: DonRoth on 7 Oct 2006 18:40 Yes, I ran it before I had looked at the diagram and used the browse buttons during the run instead of prior to running. I noticed your images did not show up as pure U8 grayscale. However, I came up with similar results to yours using recently new? LabVIEW FFT/Inverse FFT functions which will work on 2d array data (see attached).We need a math and imaging expert to help us now.Don deconvolve.zip: http://forums.ni.com/attachments/ni/170/209154/1/deconvolve.zip
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