Image Processing Reference
In-Depth Information
Figure 8.4
Design of stacking logic. (a) Truth table for generation of threshold levels
x
i
from
binary data
I
i
. (b) Example of K map for variable
x
3
. In the example,
x
3
is designed and the
function is therefore
x
3
=
I
2
+
I
1
I
0
. (c) The remaining functions.
derived. The K map for the function corresponding to
x
3
has been derived as an ex-
ample and is shown in Fig. 8.4(b). It can be seen that this corresponds to
x
3
=
I
2
+
I
1
I
0
. The remaining functions may all be derived in a similar way and are shown in
Fig. 8.4(c).
The
filtering
part of the structure consists of delayed versions of the threshold
variables
x
i
, written as
x
t
i
. These are produced by cascading sequentially clocked
D-type flip-flops.
Implementation of specific filters is carried out by forming functions
i
of these
signals
x
t
i
derived from the input and creating threshold output variables
y
i
, i.e.,
ψ
)
(
i
0
1
1
2
L
−
1
y
=
ψ
x
,
x
,
x
,
x
,
x
,
(8.3)
i
0
0
1
1
T
−
1
where
T
is the maximum number of delays.
