The Aliasing Problem in Computer-Generated Shaded Images
Certain defects, such as jagged edges and
disappearing detail, have long been an annoyance 
in digitally generated shaded images.  Although increasing
the resolution or defocusing the display can 
attenuate them, an understanding of these defects leads
to more effective methods.  This paper explains 
the observed defects in terms of the aliasing phenomenon
inherent in sampled signals and discusses prefiltering 
as a recognized cure.  A method for evaluating filters
is presented, the application of prefiltering 
to hidden-surface algorithms is discussed, and an implementation
of a filtering tiler is shown accompanied 
by examples of its effectiveness.
CACM November, 1977
Crow, F. C.
