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Z !-
r7 Sa
t
t E272 7 Xo4f
Ya. =f ry — rof (84)
3277 33
Once all the vanishing point coordinates are found, the orientation matrix can
be determined using equations (35) through (46).
Relationships Between Camera Station Coordinates and Object Point Coordinates
Once the elements of the interior orientation and exterior orientation matrix
are known, positions and dimensions in the object space can be determined, provided at
least one dimension in the object space is known. The relationships between the camera
station coordinates and the object point coordinates play an important role in this part
of the analysis.
The fundamental projective equations have already been expressed by matrix
equation (1). Premultiplying both sides of equation (1) by 0s juif, in which 9; = il à
and noting that [M]T [M] z [I], we obtain: r
N X 22 Na
T
= = ^ = 8
Y 7 Yc 0, [M] X TV. (85)
Zr - Ze -f
Letting
E M TAX
i i o
|F,| = [M]? y, - y (86)
i à O >
e. -f
[1
equation (85) becomes: d
XC > Xe By
-— = 8
Yr Ye 9; F; (87)
-7
[Zr C e
from which the following collinearity equations are obtained:
Py
= = = — 88
o Xe) (a, 2 G, (se)
i
F
Gi cx uu oO e (89)
Equations (88) and (89) relate the camera station coordinates (Xe: Ye Ze) to the object
point coordinates (Xj, Yr Zp. The quantities Els F; and A are considered known since
they can be determined from the image coordinates (x, > y, and the known elements of the
= 19 -