[Insight-users] sign changed while pointset to pointset registration

[David Macias Verde]

Hi all:

Maybe it's a silly question but, I'm doing a pointset to pointset
registration with itkPointSetToPointSetRegistrationTest.cxx, where I
have introduced changes in order to use my own images. The results I get
are sign changed. I mean, it comes up a solution which gives the
translation for the fixed image to go into the moving one. 

These are the results for ImageRegistration1 (just to test it):

Result =
 Translation X = 6.00169
 Translation Y = -1.00737


And those others are the ones I get with
itkPointSetToPointSetRegistrationTest:

Solution = [-5.97943, 1.30558]

I assume the values are right, but not the signs. Values change slightly
because I am doing Canny Edges and Danielsson Distance Map to enter to
data into my algotithm, and the original images are given to the first,
which can introduce the difference.

Of course I am sure that the fixed and the moving images are right
passed to both codes, and that they are not interchange.

Why should it be happening?

Thanks,

David Macias-Verde
Hospital de Gran Canaria Dr. Negrin
Spain