Where are built in sound file images (album art) showing in music player? (path)

Hi and thanks in advance Samsung Galaxy S 3 Mini, gt-i8190n, android 4.1.2 **My problem:** there are preinstaled/default/built in images for sound files that appear in Music Player (they're ugly for me) That's what I write about. **My question:** where can I find them, what is the path to the folder with them, can they be accessed without rooting, can they be switched? I don't need to nor I want to change album artwork with any app, I don't need to have album artwork matched with every sound file, I'd just like to switch up those random built in images to some that don't hurt my eyes with their ugliness :P And I'd really, really like to know where they are and what is path to them, even if I won't be able to change them, but at least to satisfy my curiosity, and I'd appreciate an answer with those informations the most. Please and thank You :)