03/18/2003
15-462 Graphics I
19
Linear and Shift-Invariant Filters
•Linear with respect to input signal
•Shift-invariant with respect to parameter
•Convolution
in 1D
–a(t)
is input signal
–b(s)
is output signal
–h(u)
is filter
–Shorthand:
b = a h ( = h a, as an
aside)
•Convolution
in 2D
