Registration is also performed manually in stereoscopes and stereo com 
parators but transformations in these cases are generally confined to simple 
translations and rotations of the images. 
6. Automatic Registration 
Automatic registration refers here to the electronic sensing of image 
parallaxes and the automatic feedback adjustment of prime transformations 
toward registration. There are several examples of automatic registration 
instruments, all of them rather recently devised and some of which may at 
this time be productively operative. These instruments vary widely in the 
number of transformations subject to automatic registration as may be seen 
in Table I. 
TABLE I 
AUTOMATIC REGISTRATION INSTRUMENTS 
Device 
Transformations automated 
Stereomat III (Hunting Survey 
Corp.) 
X and Y translations, first-order 
transformations for X parallax only 
Stereomat IV (Hunting Survey 
Corp.) 
Translations and first-order trans 
formations for X and Y parallaxes 
Universal Map Compilation 
Equipment (Ramo-Wooldridge) 
X translation, first-order transforma 
tions for X parallax. 
Automatic Photo Mapper (Ramo- 
Wooldridge and others) 
X translation, one first-order trans 
formation (X scale). 
ARES (Itek Corp.) 
All zero-, first-, and second-order 
transformations.