Snake Algorithm - opencv active contour - not working so well

Question

I\'m actually working on a contour detection for head side. As pictures are taken in front of a white wall, I decided to run a snake (active contour model algorithm) on the

Answer 1

If you want to implement by yourself, I recommend the paper "Everything you always wanted to kwon about snakes (but were afraid to ask)", By Jim Ivins and John Porrill.

About the OpenCV implementation, I don't know it very much, but I would you suggest you to:

• Reduce beta, so that the curvature may be stronger

• Check the image energy. Maybe the last parameter of the function (scheme) is wrong. There are two possible values: _CV_SNAKE_IMAGE and _CV_SNAKE_GRAD. You set it to 0, if I'm not wrong, and I think 0 means _CV_SNAKE_IMAGE. So, the function will assume the input image is the energy image. Again, I'm not sure how OpenCV implements this function, but I think that when you use _CV_SNAKE_IMAGE the function assumes the input image is a gradient module image. In your case, it could make the snake avoid black regions (interpreted as low gradient module) and seek bright regions. So, try to use _CV_SNAKE_GRAD as your last parameter.

I hope it can help you. Good luck!