Upgrading iTunes Artwork


I want to upgrade the quality of some of the cd artwork in my iTunes library but I cannot delete the old artwork without deleting all of the music tracks as well. How do I delete the existing artwork (not the music) so I can import (click and drag) better quality artwork in.
puerto
I know that this thread is almost dead but I have to add this information:

Originally after getting good advice herein on how to upgrade the iTunes artwork I went to work upgrading everything using Amazon Music. Then, as a back-up plan, I checked out seekacover.com. Well, let me tell you, the difference between Amazon and seekacover is like night and day. I just finished re-doing all of the artwork using click and drag from seekacover. Their stuff is first class quality.

Just wanted to share that with any readers that may still be checking in.
Best source for album artwork for me is: google images. Just type in a rough approximation of the album /artist name and search using google images. You'll get dozens of photos of the album cover in varying sizes and quality. I prefer to keep data size down by going for images about 300 x 300 but you can go higher resolution if you like.
Gdoodle: You're right - that is a great source for artwork. I am now a regular user. Thanks.
Will not let me drop album artwork in. Just added about a hundred albums. I go and do what I did before and try to add cover art and it will not let me drop it in the info page.

Highlighting all the songs in a album
Bring up file and get info. Page pops up
Find the image in goggle images
drag over and no go.

What the heck is happening.

Used the apple to get a bunch of artwork and most is OK, will have to change some
Highlighting all the songs in a album
Bring up file and get info. Page pops up
Find the image in goggle images
drag over and no go.

What the heck is happening.

Are the CD's you've ripped to iTunes formatted as .WAV files? If so, per my response above, .WAV files will not support that method of drag-and-drop as other formats. If you want to rip in high-rez and use drag-and-drop I'm pretty sure AIFF would work. Apple Lossless certainly works.

The only way I know of to get iTunes to associate artwork to .WAV files is to have iTunes fetch the available artwork via the software. The actual .WAV files do not support metadata the same way the other formats can. iTunes does a sort of runaround of this by creating some sort of path to the artwork via the softare. Unfortunately it does not support drag-and-drop for .WAV