I want to make a backup on my pc of the photos because I want to finally reset it and update it. I already tried the sc way, but there was too much quality loss on my photos. The itunes way isn't viable, because for some reason my backup gets encrypted, I already searched online, the password is the first password of your itunes account. Too bad I changed it years ago. I tried SC on an Ubuntu 16.10 pc, but I also have access to a mac (10.12.3) and a Windows 10 machine.
Use the Image Capture application on the Mac to export all of your photos. It will export the original qualities of all your photos. However, I'm not sure how it works out with "Optimize Photo Storage" on your device turned on. I'd suggest you to use this method only if you don't use iCloud's optimize storage option.
This should work on any OS, but I am sure it works in *Nix/OS X.
Essentially, we're going to manually copy the photos folder from the iPad to your computer.
If you plug the iPad into your computer with the USB cable, you should be able to mount it as a disk drive (there should be an Autoplay option in Windows, on Ubuntu it should automatically mount). Then, if you open the mounted folder, there should be a folder (which might be under some other folders) called
DCIM. This folder should contain all of the pictures you have taken and/or saved on the iPad. Copy this folder your preferred way (Cmd/Ctrl-C, cp, rsync...) from the folder to your PC, and you'll have the folders backed up.
I will update this with the exact paths by the end of the day.