CC = bwconncomp(~BW);
[junk, idx] = min(cellfun(@numel,CC.PixelIdxList))
[r c] = ind2sub(size(BW),CC.PixelIdxList{idx});
%How do you want to define vertical position? Middle, top bottom
mean(r); %middle by weight
min(r); %top point
max(r); %bottom point
