Intensity over specific range using MATLAB app

So I'm trying to create an app that imports an image. In that image u can draw vertical lines and in between those lines you can get the intensity of that area. Is there something out there that does this? or help on how to get started on this.

Thank you.

Answer 1

[Walter Roberson]

https://www.mathworks.com/help/images/ref/imcrop.html

If you call imcrop() without passing in a rectangle, it will provide an interactive cropping rectangle that the user can change.