As I know, the deleted data still store in iPhone, if they are not be overwritten, you can restore iPhone data directly, but you need some iPhone Data Recovery
programs for help, this way is for the user have no backup, if you backup your data with iTunes before, then recover deleted photos from iPhone
will be simply, follow the step.
Click the File menu and select Devices > Restore from Back up.
Open the iOS device's Summary tab. There are two ways to access this:
Click the device button in the upper right corner. (If viewing the iTunes Store, click the Library button in the upper right corner. The device button will then be visible.)
From any view in iTunes, click the View menu and select Show Sidebar. Select your iOS device in iTunes under Devices.
Click the Restore Backup button.
Hope this helps!