Locating the end points of a bridge-like structure in an image

Hi All, This is my first time posting this kind of question in this part of the stackexchange, so forgive me and correct me if this is not the right place to ask such question. In fact, i cant find any platform that is closely related to image processing on stackexchange yet.

Image is here: http://i.stack.imgur.com/goVxE.png

I have a set of images that look like what you see on the left hand column as shown in the above picture. What I am trying to detect/locate is actually the two endpoints that are shown on the right hand column in the above picture. It's quite like locating the "two ends points" of the 'bridge'.

I sincerely would like to seek for your advice and recommendation to achieve such goals. I have applied some basic morphological operations; however, either im doing it wrong or those basic morpological operations aren't working in this scenario. (i have tried making it into skeletons; however, once the skeletons are formed, I can't seem to detect the cross with 3 edges). Thanks very much.

Answer 1

[Wolfgang Schwanghart]

Hi G,

you might identify these two points by calculating a skeletonization of your BW-image.

SK = bwmorph(BW,'skel',inf);

then, calculate the branchproints with the same function. This might give you what you want.

BP = bwmorph(SK,'branchpoints');

Cheers, W.