[Matlab] [Image Processing] Snakes algorithm on image with sharp corners

[vegardkt]

Hi all!

I'm trying to implement the snakes algorithm which can be found here :

https://www.mathworks.com/matlabcentral/fileexchange/28149-snake-active-contour

I have been successful in getting it up and running, however i am having some problems making it work with my specific problem. What i want to do is identify the contour of a wind turbine blade for a series of images, which can be seen here :

https://imageshack.us/g/1/9975486/

Before anyone asks, i have already tried with various edge detectors and the seem to be a poor choice due to the need of a varying threshold in each image, and this process is needed to be automatic.

Now, the snakes function works well for objects who are not occluded and contain no sharp edges. But as you can see. My images contain sharp edges because only parts of the blade is in each image.

My question is therefore: How can i make the snakes function work on my images?
If you are reading this far I assume you have some sort of knowledge with this algorithm. My idea so far is to manipulate the external force field map and the external energy map. I am however having a hard time doing so.

If you have ANY tips, hints or suggestions for other algorithms that can be used, i highly appreciate it.

Thank you in advance

Edit : I am probably not going to have time to check this post until tomorrow. just FYI, thank you.

 

[vegardkt]

Im going to go ahead and bump this. Im still having trouble segmenting the blade. I have tried snakes a lot now and it doesnt seem like it works when the blade is cut of by the image. I have tried using standard edge detection along with edgelinking, but im still having trouble.

Are there no edge detection methods where you know the endpoints of the edges? cant seem to find any.

Any tips or hints are warmly welcomed!!