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<body class='hmmessage'>Hi,<BR> <BR> I've been using vtkThinPlateSplineTransform and have been successful to get a result applied to landmarks, but have a question for transforming a volume. <BR>
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First, is there a way to force connectivity between points in a volume?<BR> <BR>More specifically this is what I have done and where is my problem:<BR> <BR>- I created a thin plate spline transform with source points (from an MR volume) and target points (from a CT volume).<BR>- To apply the transformation to the points, I used <FONT size=2>vtkTransformPolyDataFilter and specified a vtkPolyData structure with positions (vtkPoints) and connectivity (using <FONT size=2>vtkCellArray).</FONT></FONT><BR><FONT size=2><FONT size=2>- The resulting displacement for the source points is valid and they are now moved to the target points.</FONT></FONT><BR><FONT size=2><FONT size=2></FONT></FONT> <BR><FONT size=2><FONT size=2>I want to apply this exact transformation to a volume that contains only intensities. I can use <FONT size=2>vtkImageReslice and specify the transform from vtkThinPlateSplineTransform but the volume intensities do not seem to move exactly as the landmarks do and I wonder if the problem might not be the connectivity that is not respected in the final displacement. I cannot use vtkTransformPolyDataFilter with a volume image. Does anyone have an idea what I could do to specify a connectivity constraint?</FONT></FONT></FONT><BR><FONT size=2><FONT size=2><FONT size=2></FONT></FONT></FONT> <BR>
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I have another question regarding inverse. In some examples (but not all) on the web, I see that the transform is inversed before using reslice. In what situation does the inverse need to be used?<BR>
<BR><FONT size=2><FONT size=2><FONT size=2>Thanks in advance for you help!</FONT></FONT></FONT><BR><FONT size=2><FONT size=2><FONT size=2>Pascale<BR><BR></FONT></FONT></FONT><br /><hr /> <a href='' target='_new'></a></body>
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