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<font size="-1"><font face="Courier New, Courier, monospace">Hello,<br>
<br>
with regards to this e-mail to the mailing list which unfortunately did
not get any feedback:<br>
<br>
</font></font>
<pre wrap=""><a class="moz-txt-link-freetext"
href="http://www.nabble.com/funning-observation-regarding-SetMatrix%28%29-in-VersorRigid3DTransform-class--tp20409801p20409801.html">http://www.nabble.com/funning-observation-regarding-SetMatrix%28%29-in-VersorRigid3DTransform-class--tp20409801p20409801.html</a>
I am writing to the mailing list hoping to get some more insight into the problem.
Using Rigid3DTransform and the Amoeba optimizer for registration of 2 volumes (one was manually rotated by 5 degrees around the x axis) seems to be quite challenging to me. Unfortunately I can't initialize my registration in a way which makes it compute any iterations. I do get the error "Attempting to set a non-orthogonal rotation matrix" mentioned in the subject everytime. As pinpress guessed right, there is a test for the identity matrix.
<blockquote type="cite"><pre wrap="">My guess is that in ITK library somewhere, there is a check (e.g., to check
if determinant of the matrix is exactly 1, because it is a "rigid"
transform), but the tolerance is not set properly which caused the problem
that I experience.</pre></blockquote>This test is implemented in itkRigid3DTransform.txx line 77.
I am using the following parameter values for Rigid3DTransform:
- first 9 rotation parameters are set to 0.1
- the three translation parameters are set to 0.001
And the simplex delta parameter values for the optimizer:
- first 9 values set to 5
- the last 3 values set to 0 (as there is no translation)
My question is now as pinpress already asked
<blockquote type="cite"><pre wrap="">However, is such checking necessary?</pre></blockquote>Thanks in advance for any help,
Matthias
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<pre class="moz-signature" cols="72">--
| Dipl.-Ing. Matthias Keil
|
| Fraunhofer Institute for Computer Graphics (IGD)
| Cognitive Computing & Medical Imaging
| Fraunhoferstraße 5, 64283 Darmstadt, Germany
|
| phone : +49 6151 155 212
| fax : +49 6151 155 480
| mobile : +49 173 5709746
| e-mail : <a class="moz-txt-link-abbreviated" href="mailto:matthias.keil@igd.fraunhofer.de">matthias.keil@igd.fraunhofer.de</a>
| skype : matthias.keil.office
| web : <a class="moz-txt-link-freetext" href="http://www.igd.fraunhofer.de/~makeil">http://www.igd.fraunhofer.de/~makeil</a></pre>
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