It is possible to directly recover lost media files for Samsung Galaxy , but you should make sure have backup files somewhere.
1.
Google account, if you have a google account for your android phone and
open the automaticalli sync, you can try to recover from google
account.
2. Offical PC software, generally speaking, an
android phone need to upgrade in computer via a official PC software,
such as Samsung PC studio, and this applicaiton have a automatically
backup function, when you connect the phone to computer and launch the
application, it will make a backup for your phone data, thus you can try
to find the backup from PC studio.
3. 3rd-party android assistant - MobiKin Doctor for Android, which is similar with PC studio, and it is more convenient, and the backup is more obvious.Follow some steps recover lost media files from Android phone
Step 1: Connect Android phone with computer via usb data cable, and run the program. It will automatic detect and scan your Android phone device.
Step 2: Preview and mark the media files of you need.
Step 3: Click "Recover" button restore lost media files from Android phone.