Restore photos from iTunes backup
Step 1. Scan and extract the iTunes backup file
Download iPhone Data Recovery software and install it on your computer. Launch the program and move to the mode "Recover from iTunes Backup File". All the iTunes backup files on your computer will be displayed at list on the interface. Select the one including your iPhone photos and click the button "Start Scan" to extract the iTunes backup file.
Step 2. Retrieve photos from iPhone backup
When the scan completed, the program will display all found data from the iTunes backup file on the window. At the left column, choose Camera Roll, Photo Stream, App Photos under the Photos & Videos category, then you can check all the photos including the deleted photos one by one. Select the one you desire and click the button "Recover" to save them on your computer.
Just two simple steps as above, you can extract pictures from iPhone backup easily. If you have the habit of backuping files to iCloud, to retrieve photos from iCloud, read the relevant article for help.