Graphics Reference
In-Depth Information
Figure 21.10.
Reconstruction of finitely-sampled functions.
function that has only been sampled over a finite range. No function that is nonzero
over only a finite interval can be band-limited and, conversely, any band-limited func-
tion is nonzero over an unbounded domain.
To summarize, in the context of computer graphics, what typically happens is that
we start with a signal (the signal derived from a scene that we are trying to display)
and then this signal is passed through a sequence of filters before it ends up on the
display. (A
filter
means simply anything that modifies a signal.) Multiplying a function
by another, such as a box function, is an example of filtering. We can apply a filter
either in spatial or frequency domain. The latter is common. Some standard types of
filters are
