In: Wagner W., Sz&cely, B. (eds.): ISPRS TC VII Symposium - 100 Years ISPRS, Vienna, Austria, July 5-7, 2010, IAPRS, Vol. XXXVIII, Part 7B 
330 
Figure 9. Extracted straight primitives (building 6) 
Figure 10. Extracted straight primitives (building 7) 
registration process. Figures 4 to 10 show the results of 
extracted straight lines primitives for each building in the image. 
3.3 Back projection 
Optimal building primitives were back projected into image 
space and figure 11 illustrates the result of each building. 
Figure 12 shows a closed-up view of the back-projection on the 
image of building 4. In this figure, the red lines represent the 
optimal building primitives. Column 2 in Table 1 presents the 
image coordinates of the optimal building primitives after back 
projecting them into image space. The back projection results 
show that there is a small difference in the image coordinates 
between optimal building primitives projected into image and 
the building image because of errors contained in the initial EO 
parameters. 
Figure 11. Results of back projecting into image space 
Figure 12. Enlarged image of back-projected building 4 
3.4 Similarity measurement and matching 
Similarity measurement was carried out with a 10 pixel buffer 
zone in search area. 30 pairs of coordinates corresponding to the 
vertices of the optimal building primitives are automatically 
obtained by computing the intersections of the new straight 
lines after finding new location of optimal building primitives. 
Table 1, column 3, shows the results of image coordinates 
corresponding to the extracted optimal building primitives. 
Table 1. Quantitative assessment with optimal building primitives 
Optimal building primitives 
(Object space) 
Image coordinates 
extracted manually(l) 
Coordinates of Building 
primitives projected into 
image space(2) 
Automatically extracted 
coordinates by similarity 
measurement^) 
X(m) 
Y(m) 
Z(m) 
X(pixel) 
Y(pixel) 
X(pixel) 
Y(pixel) 
X(pixel) 
Y(pixel) 
Building 1 
620217.24 
4848040.89 
167.15 
2916 
5547 
2921.22 
5544.96 
2915.14 
5544.35 
620146.18 
4848017.03 
167.15 
3098 
6094 
3103.56 
6091.23 
3098.17 
6092.96 
620168.29 
4847951.20 
167.16 
3604 
5925 
3609.60 
5922.73 
3607.72 
5923.29 
620239.31 
4847975.04 
167.16 
3425 
5380 
3427.44 
5376.69 
3424.78 
5374.92 
Building 2 
620285.81 
4847945.87 
175.68 
3635 
5032 
3640.03 
5027.56 
3634.55 
5031.68 
620297.64 
4847909.79 
175.74 
3915 
4939 
3919.02 
4936.86 
3914.40 
4940.70 
620350.87 
4847927.55 
174.70 
3778 
4526 
3783.92 
4524.45 
3778.02 
4524.42 
620338.85 
4847963.57 
175.75 
3498 
4619 
3503.87 
4617.28 
3497.11 
4617.53 
Building 3 
620386.56 
4847837.71 
174.96 
4476 
4252 
4478.37 
4250.46 
4475.77 
4251.39 
620406.61 
4847776.84 
175.01 
4951 
4096 
4949.13 
4096.63 
4952.36 
4095.65 
620442.84 
4847788.77 
175.05 
4858 
3814 
4857.49 
3816.35 
4860.45 
3814.55 
620422.79 
4847849.64 
174.82 
4384 
3970 
4386.87 
3970.20 
4384.00 
3970.30 
Building 4 
620550.63 
4848063.44 
169.83 
2739 
2980 
2746.82 
2980.75 
2738.37 
2980.45 
620504.54 
4848048.32 
169.88 
2855 
3336 
2862.55 
3336.07 
2854.51 
3337.03 
620519.95 
4848002.25 
169.96 
3209 
3218 
3217.41 
3218.14 
3208.79 
3219.29 
620565.94 
4848017.63 
169.92 
3092 
2863 
3099.65 
2863.53 
3090.62 
2863.43 
Building 5 
620753.79 
4847797.58 
176.63 
4795 
1406 
4793.49 
1408.54 
4794.11 
1407.82 
620675.77 
4847771.87 
176.59 
4992 
2008 
4991.26 
2013.39 
4990.29 
2007.80 
620705.72 
4847682.57 
176.74 
5682 
1777 
5683.18 
1782.69 
5680.77 
1777.59 
620783.60 
4847708.69 
176.61 
5482 
1178 
5482.31 
1179.05 
5481.51 
1178.80 
620563.73 
4847602.66 
188.92 
6306 
2872 
6304.02 
2876.78 
6307.17 
2872.21