How to crop an egg shape / oval from an image in C#

[anhtinh]

I can crop an image in a square, a rectangle and even an ellipse (circle). However, I need to be able to crop an egg shape / oval with the surrounding area as transparent.Now I have given myself a headache trying to find out if this is possible, and the commands needed. I dont mind if a third party DLL is needed, just as long as I can do this in C# quick, easy, and dirty.