in which all points not shown have value 0. Similarly, computing g
—
V
2
g is
the same as convolving g with A
D
, defined by
-1
-1 5-1
-1
248
6 Enhancement
Fig. 15 (a) High-emphasis filtering using a logarithmic transformation, (b) Results of
filtering. (From [43].)
These space-domain convolution operations can also be performed in the
frequency domain, by multiplying the discrete Fourier transform H
L
(or H
D
)
by G and then inverse transforming
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month, and much more.