Is the Gallery app scanning my photos? The Gallery app is now using face recognition on my images. Is this sending my images to the Samsung server? Is Samsung stealing my pictures and uploaded them to their server? How do I uninstall this app? 

Here is the settings view per request below.
It will NOT send any picture to server, it is feature to easy you task in contacts and social platforms but some times quite annoying.
System apps cannot be uninstalled on Non-Rooted phone.
So to uninstall app you need to root your phone and use any other third party app manager. However rooting voids your warranty , as far I am aware of Samsung.
And there must be option to turn off Face Recognition.
Solution:-


Go in gallery
Open a picture
Open drop down /Tap menu key/ open setting
Tap on facetag
Turn it off.