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The parallax output signals from the parallax analyzer have a magnitude 
and polarity dependent upon the magnitude and direction of the parallax between 
th e left and right images at any instant. 
Under conditions of perfect registration or zero parallax, the signals 
from the parallax analyzer will, therefore, be zero. If registration is in 
complete, however, the parallax between the left and the right images will 
vary in both magnitude and direction from point to point depending upon the 
area being scanned at any instant and upon the nature of the mis-registration. 
Under these conditions the output from the parallax analyzer will fluctuate 
in a periodic manner as the scanning spot moves about the area of the image 
and such fluctuations will repeat themselves in detail as the spot scans the 
image area over and over again. 
Figure 10 is a block diagram of the registration analyzer. It is the 
function of the analyzer to sort out the fluctuating parallax signals delivered 
by the parallax analyzer and to derive from them separate error signals for 
each of the prime registrations to be applied. 
1ST ORDER TRANSFORMATION 2ND ORDER TRANSFORMATION 
ERROR SIGNALS OUT ERROR SIGNALS OUT 
Figure 10,- Registration analyzer (6.0). 
Multipliers numbered 1 to 4 sense each of the four first-order distortions 
and provide error signals suitable for the activation of the pattern transforma 
tion circuitry. Multipliers Nos. 5, 6, 7, and 8 perform similar functions ex— 
cept that the reference signal is squared in each case, enabling these multipli 
ers to sense X 2 and Y 2 components in the parallax signals, representing 
errors owing to second-order distortions containing X 2 and Y 2 terms.