When your iPhone suddenly corrupted, you may want to recover the photos backed up with iTunes. iBackup Viewer is the right app you are looking for. With iBackup Viewer, it is easy to extract photos from iPhone backup files in 3 simple steps
When the downloading finishes, go to downloads folder, find and open the downloaded zip file, you will get a DMG installer file. Mount the installer and finish installation. (You can run the app from the installer, but not recommended).
Run iBackup Viewer after installation, the app will load all available backups automatically.
You can switch among those backups by click the corresponding thumbnail, generally the wallpaper of the iPhone will be used as thumbnails for unencrypted backups.
Click on "Photos" icon,
photos in backup were listed as thumbnails.
You can save either selected photos or the whole backed up photos to disk from the drop down menu "Export".