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<DIV><FONT face=Arial size=2>Hi All,</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>I realized that the transform in optimization is
the one mapping from fixed image space into the moving image space.
</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>But I think the transform result computed by the
registration framework should transform the moving image into the fixed
image space, this means the parameters got from the method </FONT></DIV>
<DIV><FONT face=Arial
size=2>registration->GetLastTransformParameters()</FONT></DIV>
<DIV><FONT face=Arial size=2>should be in different direction from the transform
direction in optimization. Am I right?</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>I want to compute the joint histogram after
registration, so I have to use the transform computed by registration to get
overlapped points. Can I do it in the way as the following?</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>1. Walk through all the voxels in the fixed
image,</FONT></DIV>
<DIV><FONT face=Arial size=2>2. transform each voxel index in the fixed image
into a physical point (inputPoint)</FONT></DIV>
<DIV><FONT face=Arial size=2>3. transform the point "inputPoint" using the
transform parameters got from the method "<FONT face=Arial
size=2>registration->GetLastTransformParameters()", and get
the "transformedPoint" in the moving image space;</FONT></FONT></DIV>
<DIV><FONT face=Arial size=2>4. transform the "transformedPoint" into an index
of the moving image, and compute the grey value by interpolation;</FONT></DIV>
<DIV><FONT face=Arial size=2>5. add frequency to histogram according the grey
value pair in the fixed and moving image;</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>I want to know if I used the correct tranform
parameters - mapping from fixed image space into moving image space, is
"registration->GetLastTransformParameters()" the right one?</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Many thanks,</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Yan</FONT></DIV></BODY></HTML>