(9)
A r Sr ( \ I Sr / n H 2 X , N2 ;
Ar ‘= s (Xl_X ° )+ 8^ (yi “ y » ) + 2 8xï (X ' “ Xo) +
I 1 S 2 r \2 I r / \ ( \ I
+ 2 V (y ‘ “ yJ + ^ (X| “ xJ (y,_yJ + -
A Ss , v , Ss x . 1 8 2 s . . ,
A S| = 8x (Xr " Xo) + Sy (y ‘ “ yJ + I S? (X ‘ “ Xj_ +
+ 15 (yi_ y » )2 + (xi_ ° (y ‘ - yj+ -
we can in fact, after determining the ^ X { and Ay. with the (5), go
by means of the (6) to the known terms A?'; and As ; and arrive
through the (8), stopped each at the n' term, at the two solving
systems — each made out of n equation in n unknown quantities —
generalically expressed by the above mentioned (9), allowing to define
Sr Sr S 2 r S 2 r S 2 r , Ss Ss S 2 s S 2 s S 2 s
Sx Sy Sx 2 Sy 2 SxSy
the 2n coefficients
, Ss
and —,
Sx Sy
Sx 2 Sy 2 Sx Sy
After determining the said coefficientes, we immediately find out
how to search for the values to be given the r and i - parameters to
be introduced in turn into the final transformation computation which
is performed with the (3).
In order of succession, the operations realizing the analytical pro
cedure in question require a first phase concerning: the determination
of constants r ol s Qi a and b relating to the intial stereogram; the com
putation of the X*, Y* coordinates of the known points along the
strip and in the end stereogram; a comparison of the latter coordinates
with the known ones X, Y to find out the discrepances XX, Al 7 ;
the calculation of the increments X r , Xj- relative to the previously
determined discrepancies and the consequent solution of the two systems
of equations determining the numerical coefficients of the expres
sions of r and The process of course ends in the second phase
realizing the transformation required, once we have interpolated the
values r { and to be given each point on the basis of the relative
coordinates x { and y { .
The above described process was already largely experimented in
works of the type mentioned, and its appliance appeared useful also
7