How to download my pictures from iTune Sync or backup?

Sorry, but you can't extract photos inside a backup created by iTunes on your computer.

Photos synced from your computer can't be transferred back either, they should still be on your computer in those folders you selected to sync to the iPhone.

However, you could restore your phone from that backup, and transfer the photos to your computer after that.

Transfer photos and videos from your iPhone, iPad, or iPod touch to your Mac or PC - Apple Support

If you create a backup in iCloud before you start restoring from the iTunes backup, you can get your data back by suing the iCloud backup to restore from.

You're welcome 🙂