If the photos were saved to the SD card, look there. Otherwise, if you do not have the camera settings on your phone set to save pictures to the SD card and you factory reset, then they are most likely gone.
I am with darkbreeze. Unless you saved them elsewhere like an SD card, online account, computer, etc., if you wiped the device, they are gone. Had it just be you accidentally deleted them, then you could try recovery software (which even then is not guaranteed to work), but with a reset that really isn't an option.
frederick.joe, not really. This will only occur if you have it set to do so. There are those of us that don't use that option, lots of people, so unless you have it set to sync to said account, then it won't be there. Also, syncing doesn't always upload everything, nor keep everything once uploaded. Seen way to many people who lose their phone or it dies, yet their files that should have been saved (as they synced the phone) weren't. It has flaws, this is why I prefer regular backups to say a computer.