Hi, 

I'm stocking with my contour extraction and I really need help. I've a grayscale picture of a deformed tissue we recorded with a camera. Now I have to extract the contour which is not always that easy. I decided to transform it into a black-white picture and calculate the gradient along definded radiation lines which start at the middle of the pictures to the edges. 

When I go from white to black I need to calculate the min of the gradient. But i want to get the latest min possible. how does it work? any idea?

thanks, 

sabrina