ALIASING AND ANTI-ALIASING

Aliasing:
Aliasing is generation of a false (alias)  frequency along with the correct one when doing frequency sampling .

Ex: For images, this produces a jagged edge, or stair-step effect. For sound, it produces a buzz.



Anti-Aliasing:
1.Anti-Aliasing means smoothing of the image  or sound roughness  caused by aliasing.
2.Anti-Aliasing is a technique to reduceing jaggies and stairsteps from signal.



Why Anti-Aliasing ?

Because, The output devices like Monitor or Printer doesn't have high enough resolution to represent a smooth line.



How Anti-Aliasing working ?

Anti-Aliasing reduces the Jaggies by surrounding the stair-steps with intermediate shades of gray on signal or aliased  image or aliased image.