1. Simple guide for you to solve this problem

2.  PAY ATTENTION: Don’t add any new files to
your phone’s memory card, you still can
recover deleted photos successfully.

3.  Choose a right Recovery software to recover
deleted photos from Samsung galaxy s3.
 The software I choose is Stellar Phoenix
Photo Recovery. This one can recover lost,
deleted or formatted music, video files and
other multimedia files from digital camera,
external hard drives, laptops and desktop,
USB Drives, and memory cards.

4.  After install the Photo Recovery, connect
your galaxy s3 with computer, launch the
photo recovery software, and click on the
Recover Photo, Audio, & Video button.

5.  In the “Select Media for Recovery” window,
you will notice that the SD card and the
internal storage are allocated with a drive
letter. If not so, make the setting in Samsung
Galaxy S3: Settings -> Wireless & Wifi -> USB
Tools -> Connect USB mass storage to PC, and
then plug Samsung Galaxy device into the PC.

6.  Select drive and click “start scan” at right
bottom. Scanning process may take a while if
the library is stacked with files, photos or
videos. After the scanning, the software lists
the deleted files by file type and file
extension, check out the recovered photos in
the preview window.

7.  Finally, Locate the photos you’d like to
recover, and click “Recover” button to save
the recovered files to a specified destination.
 And then what you need to do is just wait for
a while to get the files you want them back.

8. Hope this helps for you.