[NTG-context] How do I compile a "flat" pdf?

Hi guys, I am trying to create a pdf which contains some graphics that I created. I want to pass my PDF digitally but I don't want users to be able to right-click on a gfx and save it. I think this is called "flattening". Is there a way in CTX to create such a file or do I have to recompile the PDF with 3rd party software? Is there maybe even a way to flatten only specific objects like, only one picture of many or all, and leave form fields unflattened? Thanks, Sebastian