Recommend Software to Edit Images and CNC mill images

I would like to take a digitized file and be able to modify it using software. after modification I am looking to mill the shape into a block of foam. Does anyone do anything similar? What software are you using to do so and would you recommend it?

are you using a windows or macOS ? in my university they had freemill which was plugged into rhino so i guess it should work pretty well. didnt check recently if its still being used since i am not around in the computer lab much so i also have no experience with it.

but i am sure you can reshape, adapt your file in rhino accordingly. anything specific you want to work up?