Cross sectional area of nanowire

[gnicholl]

Hey, I am trying to find the CSA of a silver nanowire. I have AFM images, and in that program I can find CSA, but only on a specific line that I draw, not for the entire length. Is there a way to input the maximum light intensity of the image and associate that with a specified height? If so, how would I pair this with the width as well on the same plot?