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<p class=MsoNormal>Hi,<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>I have a question on the model to image registration example
ModelToImageRegistration1.cxx. I am using ITK 3.8.0.<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>The example defines its own metric. One that is
designed to maximize the sum of the pixels in the image that the model overlaps
with.<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>This metric overrides the SetMovingSpatialObject
function. This function appears to be doing the following:<o:p></o:p></p>
<p class=MsoListParagraph style='text-indent:-.25in;mso-list:l0 level1 lfo1'><![if !supportLists]><span
style='mso-list:Ignore'>1)<span style='font:7.0pt "Times New Roman"'>
</span></span><![endif]>Take every pixel location in the image.<o:p></o:p></p>
<p class=MsoListParagraph style='text-indent:-.25in;mso-list:l0 level1 lfo1'><![if !supportLists]><span
style='mso-list:Ignore'>2)<span style='font:7.0pt "Times New Roman"'>
</span></span><![endif]>Add it to a list if it lies within the object.<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>The GetValue function then only uses those points to
optimize the metric. In the GetValue function the transform is applied to
these points and uses where the points currently get mapped to calculate the
metric value.<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>Does this make sense? Only the points where the object
and image initially overlap are used in the registration process. Isn’t
the object of the registration to increase this overlap. If the model and
image have no overlap, but an appropriate initial transform parameter set is
provided, then no points will get selected in the SetMovingSpatialObject
function, and registration will not occur.<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>Am I missing something?<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>Thanks<o:p></o:p></p>
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