A web-based image to PTC QR generator for Petit Computer. Choose a file from your computer (again, this is image > GRP, not the other way around) and generate QR codes directly.
This won't suffer from the same problems as PTCUtilities, but it can only be used to edit/create GRP files.
See also PetitEditor
(Created by OBONO. See http://petitcomputer.wikia.com/wiki/Japanese_User%27s_Link "OBONO's Dairy / Petitcom (by OBONO)" )