Graphics Reference
In-Depth Information
Fig. 10.6
Detection rate versus number of scan bands for scan band width = 10 and 5
(which we consider as failed detection). Therefore, having more scan bands increases
the detection rate as seen in Fig.
10.6
for both cases of the scan band width, i.e., 10 and
5 pixels. The detection accuracy with 8 scan bands is over 90% in all test datasets.
This is an important observation because this implies that for the IPM images of
size 360
500, processing just 8 scan lines with 10 pixels each is sufficient to get a
detection rate of 95%, instead of processing the entire 360
×
500 sized image (which
is usually the case in most conventional methods). This figure also plots the detection
accuracy for varying scan band width, i.e.,
w
B
=
×
10 and 5 in Fig.
10.6
. A higher
scan width captures more information, implying better detection rate. Therefore, it is
expected that bands with width of 5 pixels have lesser detection rate. However, it is
noteworthy that as the scan lines increase to 8, the detection rate is nearing 90-95%
in both the cases of scan band width. The implication of this on computation cost
will be discussed later.
It can also be seen that for a band width of 10 pixels, the difference in accuracy
between
n
B
=
8 and 4 is less than 20% in each dataset. Therefore, one can decide
to go for 4 scan bands instead of 8, trading off accuracy by less than 20% for half
the number of processors.
10.4.2 Computational Complexity Analysis
Let us now consider the main operations involved in the proposed method. Each
k
×
k
filtering operation involves
k
2
multiplications,
k
2
1 additions and 1 comparison.
Assuming all operations are of equal complexity (simplified model), the total number
−
