is there a way to extract image information in text format?

Hi there-

I work in the architecture field and I'm interested in just processing the
raw data that radiance generates instead of looking at images that might be
generated. I want to build my own spatial mapping of illuminance values in
another visualization tool. Sorry for the newbie question!

How would I do that? Can anyone lend some hints of where I would look to
see this, files, etc?