Juan Vuletich wrote:
... I believe that existing rasterizers for 2d graphics use either pixel coverage or super sampling. Please point me to some reference if I'm wrong.
Applying a real filter to a continuous ("analog") function and then sampling is something quite different.
Not really. Pixel coverage is just applying a very simple filter. Super sampling is approximating such a simple filter. Admittedly they might not be the best filters possible, but for vector graphics it often doesn't make sense to use filters of very high orders, as that usually introduces ringing. Note that Inkscape could do with a slightly better filter though. It more or less uses a box filter now, using a tent function would probably be better (no ringing, smoother result).
For most renderers the main problem is combining different layers in such a way that no seams appear. I've thought of some solutions that involve adding another channel that more explicitly records the shapes. And if you do super sampling all the way the problem is also reduced. But if you have a method that can eliminate the seams which has the following properties I'll be first in line to see it implemented in Inkscape: - No seams! - Allow compositing AFTER rasterizing, still without seams. - Rasterization not much slower than normal rasterization. - Compositing not much slower than normal compositing. - No or very little additional memory usage.
As for subpixel rendering with Inkscape, you could just export to an image with three times the width and apply some postprocessing. Not perfect, but it would allow a more or less fair comparison.