If I understand well, pstopdf uses ghostscript .
"luafication" will use ghostscript again ?

sure, what else ... actually, pstopdf started out as some perl script long ago (when we started using pdftex) and we needed it not only in order to convert to pdf, but also to clean up some mess in eps files that interfered with the process

So what about a lua wrapper of libgs.so libgs.dll ?
code should be not complicated
http://wiki.contextgarden.net/User:Luigi.scarso/luatex_lunatic#Ghostscript

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luigi