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3.2 AP/C Software Improvem ents 
This existing real time software can be considerably improved; 
a) Flexibility of Programming 
First of all it is virtually impossible for someone attempting 
to change portions of the two man year real time program without 
intensive, timeconsuming analysis of the existing program. 
In order to achieve this programming flexibility it would 
therefore be necessary to reprogram it in modular form. 
aa) A common area should contain all data to be transferred 
anywhere, 
¿ib) the common area should also contain all input-output 
values, 
ac) all other program parts can remain in independent subroutines 
which may be exchanged at will, but which are linked by a 
control program, 
ad) such a program is of course usable for additional 
input-output devices. 
b) Improved Formulations 
♦n. 
The existing mathematical formulations are also in need of 
improvements. The implementation of such simple mathematical 
reformulations has sofar been severely handicapped by the 
non-modular program structure. 
bl) First of all an improved interior orientation procedure, 
calculating not only the fiducial mark translations for the 
principal point, but also a k 0 rotation referring the stage image 
coordinates conventionally used to real image coordinates 
necessary for point transfer. 
Also desirable is the transformation of image coordinates to 
the image deformation values obtained by the four fiducial 
positions.