setting --png in an .ly file (without using command line)?

[Mark Polesky]

When I want .png output, I usually type something like this
in the command line:

lilypond -dbackend=eps -dno-gs-load-fonts -dinclude-eps-fonts
--png my_file.ly

Is it possible to do all of this from inside the .ly file?
Using the ly:set-option command, I can do most of it:

#(ly:set-option 'backend 'eps)
#(ly:set-option 'gs-load-fonts #f)
#(ly:set-option 'include-eps-fonts #t)

But I can't figure out how to set --png from within the file.
Can I?

Thanks,
Mark