I found out how to do a couple of different screen sizes and some filters or video modes through the SCUMM options menu, but that is not the same graphics options I encountered earlier.
I found the faq which says how to add the filter prefix to the game, but can't get that to work on PSP, and most of the instructions seem to be for pc. I had figured out how to alter the graphics filter and screen size, but can't seem to get the same options now. I have been using SCUMMvM on both my mac and PSP.