On Mon, 09 Feb 2009 18:24:05 GMT, John A. wrote:

On a Bayer-filtered sensor 1/2 pixel = 1 photosite. In your sequence
remove step "0" (which is pretty much meaningless) and replace "pixel"
with "photosite" and you've pretty much got what I've described.

You still don't get it. First of all, the "0" step was only used
to identify the surrounding 4 pixels (sensels). Traversing from any
pixel to the next requires stepping the distance from one pixel to
another, which is *not* 1/2 the distance/size of a pixel. If it'll
help, place four hamburgers on a plate. How far is it from the
center of one hamburger to either of its adjacent neighbors (not the
diagonally opposite burger). If you say it's 1/2 of a hamburger's
diameter, you've bitten off more than you can chew.