Digital BW, The Print

> Then how is grayscale handled? Are every 4 sensors averaged into
> one,

No, not typically...

> or is
> interpolation done for each sensor individually?

Yes.

It's not a straight forward problem.  Remember, each sensor from a quad RGBG
isn't looking at the exact same thing...so they are measuring different
"space", so to say.  That means you just can't necessarily "combine" the
four (three) color values...but on the other hand, none of the values are
really complete unto themselves.  Answer is, no matter what is done, it's
got to be processed...and in doing so, it makes it more so not reality,
though it may look great.

Austin