I use MP3Tag. I have a Sansa Fuze.
I noticed that some of my album art wouldn’t appear on the Fuze. On my PC, I checked out the tags, and found some of the JPGs as large as 500KB!!! In fact, a lot of them are 170x170 pixels and 255KB!!! It doesn’t make sense!
Now, I used to use MusicMatch Jukebox to tag files, and thought that perhaps it had inflated those JPGs somehow. But, I stopped using that software a long time ago, and there are still other weird things going on:
I recently noticed that if I copy a 200x200 or 240x240 JPG from the Internet onto the Windows Clipboard, then paste that JPG into MP3Tag, my album art runs 30-50KB. However, if I first save that JPG to my hard drive, then use the Add Cover option in MP3Tag, the same JPG will be half the size—about 15 to 25KB.
Remember, the JPG size in KB determines whether or not the album art appears on my Fuze; although these are just kilobytes, they still matter.
Does anyone understand why JPGs are enlarged when using the Windows Clipboard? Is there some kind of hidden watermarking going on or something?