How can i highlight the wrinkles in the image?

[PeterChang]

I am extremely new to ImageJ, I have no clue where to start.

Say i have a image of a thumb with wrinkles. How can i pick out the wrinkles and calculate the pixels of those wrinkles.

what will I need to do? Maybe LoG filter?

http://i.imgur.com/lkFGwbh.jpg

Thank You