Selection within circle

selection

#1

Hi all!

I am trying to analyze the area colored white within a circle with the rest
colored black.

I draw a circle of specified measurements, clear outside and set the
threshold to make the selection but the selection keeps selecting the white
background with the white area within the circle. How could I only measure
the white area in the circle I drew, please?
Thanks!


#2

Which program are you using?