I saw an interesting paper in 1999 (very cutting edge !) Genetic Snakes for Image Segmentation that might be of interest as a starting point : http://link.springer.com/book/10.1007/10704703/page/1#page-1 in Evolutionary Image Analysis, Signal Processing and Telecommunications

Lecture Notes in Computer Science Volume 1596, 1999, pp 59-73

Thank you for the replay. Indeed, it is an interesting starting point.

I'm dealing with different complex shapes. I found that graph cut method can solve this problem. any suggestions?

I think that SVM should be useful in your case. AAM and ASM might be useful also.

Thank you Sidi

You are welcome Amine