Comment 1 for bug 141326

I can confirm this, and that the visual artifacts only occur under certain circumstances.

On the screen of my 6 month old laptop the image was dark, with a near yellow-green tint, and appeared heavily artifacted, while others liked how chocolate-like it was and couldn't discern any visual artifacting at all. On top of that, to be sure that this wasn't a common image problem that I somehow wasn't aware of before I scrutinized the older Ubuntu default wallpapers, and about ten of my other wallpapers of similar hues and found none that suffered from similar problems.

I ultimately decided to calibrate my monitor with GAMMApage and various visual guides, and ending up with with an overall Gamma of around 2.0 - the difference was night and day. If you have a well calibrated monitor and want to see how the wallpaper looked like on my - and from the looks of things on the Ubuntu forums - many other laptop lcds, see the attachment here:

http://ubuntuforums.org/showpost.php?p=3406285&postcount=108

Unless your intention is to scare off laptop users, the wallpaper really needs to be refactored to not depend so finely on monitor calibration or, failing that, replaced with a more suitable entry from the Gutsy art wiki.