General :: How To Recover Corrupted Photos

My mother-in-law ran out of space on her Samsung Galaxy S3 GT-I9300, 32GB (note that she has no microSD, only internal memory), and requested that I get everything onto a DVD to clear up some space. I initially copied and pasted 3 folders of her photos (approximately 800+ files) into a re-writable DVD successfully and she was happy with it. She got me to delete those folders on her phone. Following that, she decided that she needs more space so she wanted me to do a cut and paste into the DVD instead. Since a cut and paste is much faster than a copy and paste, I very much obliged. There were up to 12 folders containing 4,000-5,000 photos from her various trips around the world. The estimated time to completion was around 2-3 mins, so I decided to surf the internet a little while waiting. To my dismay, I realized that my mother-in-law was looking through her photos "one last time" before it disappears from her phone - But I couldn't do anything else to salvage what she did at that point of time. Unsurprisingly, the photos were all corrupted and although they managed to fit into my DVD (total of 2.02GB), each of the corrupted file was 3.2-3.5GB in size!! I have no idea how that is possible, but it still says that when I look in its properties. No clue how all of that can fit in a tiny DVD, but I guess the corrupted photos were presenting inaccurate information. Anyways, surprise surprise, no photos in her phone as well. I ensured that she did not use her phone at all since, to make sure any existing memory of the photos will not be overwritten. She has never ever backed up her phone since buying it last year - I just did one with Keis that took 4.5 hrs.

I have since tried several of the top data recovery software on both the phone and DVD with no luck at all. With regards to the S3, it is on Jelly Bean 4.1.2 and has no USB mass storage capabilities (no "USB Utilities" option in settings). I have tried looking at apps to unlock UMS, but none works with internal memory for the S3. Also, most programs require rooting of the phone which I cannot risk voiding her warranty with. Furthermore, who knows what will happen to the memory of the lost photos when I root the phone and rollback the version (was planning to get it back to ice-cream sandwich so that I can access UMS). Tried using flashtool to downgrade the phone as well, but can't find a suitable ROM (again, not confident of keeping lost photo memory by doing that - don't wanna risk it).