iphone photo size inaccurate

Hi all,

I'm sure that this is a dumb one, but i can't figure it out. I'm trying to free up space on my 5s.

My phone is showing 4.41gb over 146 pictures in terms of memory usage. However, when i go to photos on the phone, it says that that i have none. Further when i connect to iTunes, i can verify that i am not syncing photos (iTunes summary at of memory usage matches my phone saying that i'm using 4GB of memory for pictures).

I've tried backing up the phone, doing a full reset and then restore, however the 4gb comes back over.

i'm running iOS 8.1.3. Is there a way to reset free up this memory without having to do a reset and then manually reloading all of my settings (which i assume would free up this space)?

Many thanks in advance!