Yes, I left out the whole subpixel thing from my explanation, as that makes things considerably more complicated. It's still a major factor though, and in some cases it makes for some really odd results. For instance, with the barcodes I was talking about before, they were pure black on a pure white background. As such, you would expect any interpolation artifacts to be some shade of grey (R=G=B), but that was not the case. Some lines would have red or blue shadows at the edges, due to subpixel positioning.