What is AA sampling?

[Force Flow]

What is the purpose of "sampling" a pixel in antialiasing?

Yes, it helps rid the image of jaggies in the end, but what exactly is sampling? Does it take an average of something to arrive at a pixel's color? Does it go by pixel to pixel seperately, or does it rely on groups of pixels to determine color?

 

[HOCP4ME]

I'm not sure, but I think it's something like this:

I don't think pixel color has anything to do with it. The purpose of AA is to reduce jagged edges and the dreaded "stairstep effect". To do this, the graphics card alters the HSB values of the pixels surrounding the actual edge. I'm not quite sure what sampling is, but I know that the more times a pixel is sampled, the smoother the edge becomes.

I think it's like the digitizing of a sound wave. Look at a sound wave after it's been sampled at 11,250Hz. It will look very jagged, like stairs going up and down. Then, look at a sound wave after being sampled at 44,000Hz. It will look very smooth. The same thing happens with AA, more samples = smoother lines/edges.

I could be completely wrong about this, someone please explain it in more detail.