I have recently been trying to systematically extract album artwork from my iTunes library, such that I can use them elsewhere.
I understand that all the album artwork is stored in the
Album Artwork folder, inside iTunes-specific
.itc2 files. I have researched and found that these files are simply wrappers for PNG, JPG, and RAW image data.
Which is fine - I can extract those images as I wish - however, I cannot determine how iTunes knows which
.itc2 file belongs to each album. For playlist artwork, I have found that the second part of the file's name is equal to the
Playlist Persistent ID found under the corresponding playlist in the
iTunes Music Library.xml file. Yet it seems the same is not true for album artwork - there is nothing like an "Album Persistent ID" parameter.
So how does iTunes know which album each album artwork file belongs to?