The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences. Vol. XXXVII. Part B5. Beijing 2008 
764 
D - is a diameter of broadening ring 
As a consequence we obtain modified formula of resolving 
power: 
W 
it ■ 2r 
sUSX 
(20) 
4. RESULTS AND CONCLUSION 
The part of results in table 1 is representative for all test. 
Visually, best of all is to compare both methods in the lens 
resolution map, presented in the figure 4. 
Star 
number 
R 
[L/mm] 
Rw 
[L/mm] 
Star 
number 
R 
[L/mm] 
Rw 
[L/mm] 
1 
45,56 
37,10 
49 
48,03 
47,31 
10 
37,83 
28,69 
58 
44,30 
43,87 
19 
26,31 
16,88 
67 
23,46 
13,09 
28 
18,63 
8,43 
76 
16,54 
8,19 
37 
15,60 
8,78 
85 
13,31 
7,50 
46 
12,11 
7,32 
94 
12,39 
6,22 
145 
45,61 
44,03 
97 
47,81 
38,44 
154 
35,10 
27,19 
106 
38,58 
29,72 
163 
28,85 
18,45 
115 
27,25 
16,97 
172 
18,24 
9,56 
124 
20,46 
12,50 
181 
15,18 
9,22 
133 
14,88 
8,26 
190 
13,50 
9,11 
142 
12,92 
8,86 
Table 1. Results of resolution in classical and my own approach 
in four circumradial directions. 
It is worth to notice, that there is a place in the lens, where 
distortion influence is negligible (coefficient close to zero). 
Such place in classical cameras correspond to principal point of 
best symmetry (PPS). 
R [L/mm] 
Rw [L/mm] 
Mean value 
19,78 
12,18 
Median 
16,05 
9,18 
Standard deviation 
8,88 
8,19 
Min 
10,48 
3,18 
Max 
48,03 
47,31 
Variance 
78,92 
67,03 
Correlation 
coefficient 
0,95 
Tab. 2 Statistical comparison of results. Resolution can be 
present also as resolution map (figure 4). 
Figure 4 Comparison of resolution computed according to 
classical approach (right image) and according to discussed 
method (left image). 
5.CONCLUSION 
Computation of fisheye lens resolution according to proposed 
method enables elimination of geometric aberration influence 
on resolution (especially distortion). When absolute values are 
noticeable, distortion has a great influence in case fisheye lens 
cameras. Additionally, resolution map can be useful in 
designing calibration tests. Dependency of Cassini oval area and 
ellipse area of broadening can be used in lens distortion 
determination. 
REFERENSES 
K. R. Castelman, Digital image processing, Prentice Hull Upper 
Saddle River, New Jersay, 1996 
J. Wozniak, Podstawowe techniki przetwarzania obrazów, 
WKL, Warszawa 1996