When Batman Arkham City first came out, I bought it for PS3 and beat the game while finishing a few extra side missions. Since then, I've gotten rid of my PS3 copy and got a steam version. I still have the saved file on my PS3. I wanted to know if I could somehow transfer my game saves from my PS3 to my steam account?
The PS3 save files are stored in a proprietary format which is not designed to be handled or integrated by any other software than Sony's own software. This makes all of the PS3 save files unusable by any other system.
Any software can potentially be reverse engineered to fit another system than what was originally intended, but this would also mean breaking a host of copyright laws.
If there exists a third party software that opens up the PS3 save files, I don't know of it, but it would definitely not be legal.