Since System Restore is for the Operating System, if this is not an OS issue but a lost item in the photo edit program, it should neither restore or lose what's in the photo edit program.
You didn't reveal much but if you don't want to lose files, keep backup copies.
Can system restore be undone?
I used it to go back 3 days and lost things I needed in a photo edit program. Will they still be there if I use sys restore again?