how to find border irregularity of skin lesion?

I have determined other features of skin lesion except this. Please help me out with this feature extraction

[Image Analyst]

OK. We'll try.

[joynob ahmed]

what are the ways of finding this? i have learned about drawing best suited ellipse,area to perimeter ratio and compactness index.which is preferable?

[Hank]

If there is strong contrast between the lesion and the surrounding skin this assisted freehand tool may help. Can you attach an example image?

[joynob ahmed]

As i have to perform this operation on more than 200 images it is not possible to do this by hand drawing.Though I didn't understand your answer I have attached an image.

Answer 1

[Ralf U.]

A simple (not necessarily robust) way to do this is to convert the image to B/W (threshold after Gauss filtering) and use the bwtraceboundary function to determine the boundary.