Identifying gradient direction of edge (inwards\outwards)
 

I am trying to find whether the gradient of an edge is pointing inwards or outwards (out of image) in order to identify tumors. Any ideas on how to do this elegantly?

[URL="http://i.stack.imgur.com/s8SI5.png"]boundaries image example[/URL]

Thanks!



[url=https://stackoverflow.com/questions/37905063/identifying-gradient-direction-of-edge-inwards-outwards]更多...[/url]