I use R for my stats analyses and I am trying to use it as well to do some image analyse. I am doing some staining to potato slices, the staining turns my potato slices dark brown in the parts where is the compound I want to see. So I used package "jpeg" and "lessR" so I could have a section of my image analyse to get the RGB values. But I just can make a rectangular section, and like that, I lose parts of my stained image. Is there a way where I can "tell" R to analyse all the slice?

Attached is an example of my images. Thank you in advance.

Claudia