What are differences between aliasing and anti aliasing?

Answer 1

I'll take a shot at this, though it's a bit difficult to explain. OK.

Let's say you've got an array of pixels:

12345

67890

ABCDE

If you try to draw a single black pixel line at 45 degrees on

a white background it's going to hit parts of, say,

45

89

AB

But pixels are indivisable, so each of those pixels is either on

(white) or off (black). Anti-aliasing attempts to correct for this

by painting the various pixels touched by the line in various

shades of grey. When viewed from a distance, the greys blend

nicely and the line appears much closer to the desired result.

This approach minimizes the "jagged line" affect when lines or

edges are at some angle other than horizontal or vertical.

So..."aliasing" is just what happens if you don't have some sort

of "anti-aliasing" technology to solve the problem.

All in all, a relatively simple concept...but difficult to explain!

Dave