[Qgis-developer] Meaning of Georeferncer transformation types
eko at lanet.lv
Sun Mar 11 10:48:56 EDT 2012
Please correct if I'm wrong.
The formulae for the Affine transformation can be expressed as follows:
Xc = r5 + Xp * r1 + Yp * r3
Yc = r6 + Xp * r2 + Yp * r4
(Xc, Yc - new coordinates;
Xp, Yp - pixel location;
r1 .. r6 - coefficients.)
In Quantum GIS Georeferencer the meaning of different transformations
are as follows:
Linear - special case of Affine transformation where r3 = 0 and r2 = 0.
Helmert - special case of Affine transformation where r3 == r2.
Polynominal 1 == Affine transformation.
Thank You for Your time.
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