Aliasing

Aliasing is a phenomenon that occurs when sampling a continuous function with insufficient resolution.

Antialiasing

Antialiasing is the application of techniques that reduce or eliminate aliasing

Antialiasing: Increasing Resolution

This method only lessens the problem

• Costs 4 times memory, memory bandwidth and scan conversion time

Antialiasing: Unweighted Area Sampling

Drawing a line as a 1-pixel width rectangle

• For now pixel is unit square centered on x-y intersection
• Midpoint algorithm: pick single pixel closet to center line of rectangle. This is a form of point sampling

Antialiasing: Unweighted Area Sampling

Set each pixel’s intensity value proportional to its area of overlap covered by primitive

• Note more than one pixel/column for lines of 0<slope< li="">

Antialiasing: Unweighted Area Sampling