Aliasing and antialiasing

CS 248 - Introduction to Computer Graphics
Autumn Quarter, 2008
Marc Levoy
Lecture notes for Tuesday, October 7

Table of contents:

• Frequency domain analysis of sampling (a quick tour)
  • Spectral representations
  • Fourier series: periodic functions
  • Example: sum of sines
  • Spectra: a pair of graphs
  • Representation using complex exponentials
  • Fourier integral: aperiodic functions
  • Fourier transform
  • Example of a transform: box and sinc
  • Dualities
• What's the best way to prevent aliasing?
  • Raising the sampling rate versus filtering
  • Problem: fixed resolution displays
• Supersampling followed by resampling
  • The resampling pipeline
  • Preconvolving r and g
  • Approximations
  • Supersampling versus filtering
  • What supersampling and averaging down accomplishes

I don't have time in this course to show you what supersamping and averaging down looks like in the frequency domain. If you're interested, look at this handout from CS 348B.