Hi Waqas,
I understand that you want to calculate path from the given .MAT file. I see that your code was not working for this example due to some distortions.
One useful function to use here is bwareaopen() which removes all connected components (objects) that have fewer than P pixels from the binary image.
I am attaching a code snippet for better understanding.
Igray = mat2gray(dispfield);
th = multithresh(Igray,1);
Iseg = imquantize(Igray,th);
%imshow(Iseg,[])
se = strel('disk',1);
BW1 = bwperim(Iseg == 1);
BW1 = imdilate(BW1,se);
bwedge = bwareaopen(BW1, 100); % removes all connected components (objects) that have fewer than P pixels
[Y,X] = find(bwedge);
cracklinefit = fit(X,Y,'poly3','Normalize','on');
% cracklinefit = fit(X,Y,'poly3','Normalize','on','Robust','Bisquare');
outputArg3 = [1:size(bwedge,2)]';
outputArg2 = round(cracklinefit(outputArg3));
Hope this helps.
