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<DIV><FONT face=Arial size=2>Hi everyone,</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>I have a question about the
'MultiResMIRegistration' application provided by the Insight Applications
software.</FONT><FONT face=Arial size=2> </FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2> This application uses the ITK
registration framework with the following combination of
components:</FONT></DIV>
<DIV><FONT face=Arial size=2><BR> -
MutualInformationImageToImageMetric<BR>
- QuaternionRigidTransform<BR> -
QuaternionRigidTransformGradientDescentOptimizer<BR>
- LinearInterpolateImageFunction</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>I've noticed that the result returned after the
registration process is an affine matrix 'M * x + O', where:</FONT></DIV>
<DIV><FONT face=Arial size=2> </FONT><FONT face=Arial size=2></FONT></DIV>
<DIV><FONT face=Arial
size=2>
a) 'M' is a 3x3 rotation matrix representing the 3 rotation freedom
degrees. </FONT></DIV>
<DIV><FONT face=Arial
size=2> They
are calculated using the mutual information and multiresolution
registrator component;</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial
size=2>
b) 'O' is simply an offset, representing the 3 translation freedom
degrees, </FONT></DIV>
<DIV><FONT face=Arial
size=2> BUT
IT IS NOT CALCULATED BY THE MUTUAL INFORMATION MULTIRESOLUTION REGISTRATOR,
</FONT></DIV>
<DIV><FONT face=Arial
size=2>
because this offset is computed by the preprocessor component, before
calling the registrator.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>All of this leads to a great problem if we want to
registrate 2 images, where the size of their fields of view are different
(eg., a MR coronal image showing a brain slice and a second
coronal image (CT) showing a brain slice and part of the
neck).</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>IS THERE ANY OTHER MUTUAL INFORMATION REGISTRATION
APPLICATION THAT CALCULATES THE 6 FREEDOM DEGREES USING THE REGISTRATOR
COMPONENT?</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Thank you very much for your
attention.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>José Ángel Tavira Rodríguez de Liébana<BR><A
href="mailto:jat@navimetric.com">jat@navimetric.com</A><BR></FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
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