I tend to think of the Art Institutes as diploma mills.
LA has a lot of good art & design schools. Off the top of my head, CalArts, Otis, and the Art Center College in Padadena come to mind. I know someone with an art degree from Long Beach State, and she loved their program. I’d suggest you keep looking, and only seriously consider the Art Institutes if you absolutely can’t find the equivalent programs elsewhere.
Here are a couple of forums that could probably give you more specific advice -
http://talk.collegeconfidential.com/visual-arts-film-majors/