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Speckle Autocorrelation

version 1.0.0 (3.09 MB) by Marcoleonetti1
Perform the Fourier transform based autocorrelation of grayscale frames to measure the speckle size. Also work with stacks of images

22 Downloads

Updated 24 Jun 2021

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Takes frame (or stack of frames organized in x-y-FrameIndex) as input and performs the autocorrelation in x-y employng the Fourier ranform apporach. The resulting autocorrelation frame is averaged out for each input frame of the stack. After autocorrelation maxima is found, I compute the radial averaging. On the radial average of the AC, I perform Guassian fit to extract sigma and from that the FWHM. Togheter with this software I also provide a couple of speckles realizations (in staks or single frame in the files "Frm_Stack_Trial.mat", and "Frm_Trial.mat") . This routine also needs the radial average function radial_avg2.m (included).
[Frm_stack] : the input is a 3-d or 2-d matrix containing the speckles in the format x,y,,frame-index.
[FWHM] : Full width at half maximum of the speckle size (obtained with Gaussian fitting)
[AC XX] : Profile of the autocorrelation of the speckle frame; "plot(XX,AC)" to visaulize it
[curve] : result of the fit.to visaulize it "hold on; plot(curve)"
See also https://mlphotonics.wordpress.com/

Cite As

Marcoleonetti1 (2021). Speckle Autocorrelation (https://www.mathworks.com/matlabcentral/fileexchange/94765-speckle-autocorrelation), MATLAB Central File Exchange. Retrieved .

MATLAB Release Compatibility
Created with R2019b
Compatible with any release
Platform Compatibility
Windows macOS Linux

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