With a Bayer pattern it is possible to select 4 pixels bin them and create an image free of chromatic aberation caused by demosiacing algorithims. This is all obvious but I'm surprised all cameras don't have this option.
One Bayer cell can e.g. be:
[r g1
g2 b]
If you generate one full-color (co-sited) rgb triplet as :
ro = r
go = mean(g1, g2)
bo = b
Then you get a 1/2 x 1/2 resolution image where the red color plane is shifted slightly towards upper left, and the blue plane is shifted slightly towards lower right.
I think it makes more sense (for a simple algorithm) to interpolate/filter each plane separately (so as to generate full-resolution color planes). This still would not generate the highest possible luminance resolution, and would do nothing to reduce the impact of aliasing at the recording stage.
-h