Sorry to hear that but I doubt you can recover pics after a factory reset.
However, You can check any cloud services (Dropbox, onedrive, Google drive, Google photos, etc ) that you had on the phone earlier to see if they've backed up your data. Even certain cleaner apps back up data to a cloud. If you are lucky you just might find some app that backed up your pics without your knowledge (that you accidently enabled).
Happened to me once. Switching between my previous phone and the note, I switched from Dropbox to google photos. However, probably because of my prev setup, even on my new phone Dropbox was backing up my camera reel.