There's a thread somewhere on the forum with a number of such pictures. Both US and elsewhere I believe. Some really impressive works.
At least two... http://www.ww2f.com/threads/only-now-did-i-appreciate-large-scale-camouflage.58958/ and www.ww2f.com/threads/whats-there-camoflauge.34825/
I'll see what I can find. Seem to remember one of a field with sheep grazing on it over one plant in Germany. It may have been covered in a thread on the Axis History forumm