I've been looking around, and I can find a few, simplistic, passing references to the idea that feathers evolved in part as camouflage, but these references either do not expound on the idea or suggest that coloration of the feathers served the camouflage purpose. See, e.g., http://www.evolutionary.org/talk.htm ; http://www.hras.org/sw/sciencedino3.html
I haven't found anything on your idea that feathers served to delay pattern recognition, which is really quite interesting. It certainly seems that simple light diffraction serving to "blur" the outline of prey would precede specific camouflage colorations.
I'll keep looking.
as sophisticated eyes and scaled hides long preceeded the development of feathers, presumably so to did sophisticated color camouflage patterns.
I'm given to understand that evidence suggests that early "feathers" were scales with "fringed" edges.
these do not seem to me to be likely to have much thermal insulation value, but I tend to think the "blur" they'd create would have been useful in recognition-denial - a major enhancement of earlier camouflage schemes.