Call bwmorph() to get the branchpoints then use that to erase the branch points. Then label each curve and call bwmorph() to get the endpoints to get the straight line distance. Pretty easy, in fact you've probably already done it by now. You might have gotten something like (untested):
bp = bwmorph(mask, 'branchpoints');
mask(bp) = false; % Erase branchpoints.
[labeledImage, numRegions] = bwlabel(mask);
for k = 1 : numRegions
thisRegion = ismember(labeledImage, k);
endpoints = bwmorph(thisRegion, 'endpoints');
% Get coordinate
[r, c] = find(endpoints);
euclideanDistance(k) = sqrt((r(end)-r(1)).^2 + (c(end)-c(1)).^2);
area(k) = sum(thisRegion);
tortuosity(k) = area(k) / euclideanDistance(k);
end
How does that compare to your code?
