how to use code 'improfile'?

I use the code 'improfile' to find the threshold values of specific the crack in my picture.

like the picture below,

and then i get the figure that show the threshold graph values in my picture.

but I can do this one graph per one time.

If I want to find the threshold values in 50 graph in my picture for average them.

How should I do?

Thank you ^^