Hi, there
If you didn't back it up or extract it to your computer in between the time you created it and the time you deleted it, it is gone. Permanently. There is no "undo".
If you have the backup data then you can recover the deleted photos in iphone 4s.For recover deleted photos follow the below steps.
Steps to follow to recover deleted photos from iPhone 4S :
1. First of all turn on the iphone 4S.
2. After turn on locate the backup application where you got stored.
3. So,open it by double tap on it.
4. Now find and go to the photos folders.
5. Here select the photos which you want to recover.
6. After selecting tap the options and click the restore option.
7. After restore check the photos recovered or not in your iphone 4S.
Thank you.