Is there a way to download all of the album artwork from my current library?

Hello,

I'm trying to optimise my iTunes music library by editing and compressing album artwork. I have a lot of artwork of different sizes, some downloaded, some scanned, some of it is even custom stuff I made for my own amusement. Anyways, the image editing is not the part I'm having problems with, it's getting access to the artwork files. I tried accessing all the artwork in the iTunes folder, but it seems to be encrypted and inaccessible. My question — is there a way I can download/access all of the album artwork from my current library at once, so I don't have to go through the insurmountable task of clicking on every single one of my +1500 albums and drag-and-dropping the artwork outside?

To be clear, I am NOT interested in those applications that "fix" mislabeled music and download artwork automatically. As I stated before, some of my artwork is custom and I purposefully don't want to replace it, I just want to edit all of the image files I already added as artwork.

I'm running iTunes 12.8.2.3 on High Sierra 10.13.6.

Thanks in advance!