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<P class=MsoNormal style="MARGIN: 0cm 0cm 0pt"><SPAN lang=EN-GB><FONT
face="Times New Roman">Thank you to all how respond to my last
email</FONT></SPAN></P>
<P class=MsoNormal style="MARGIN: 0cm 0cm 0pt"><SPAN lang=EN-GB><FONT
face="Times New Roman"></FONT></SPAN> </P>
<P class=MsoNormal style="MARGIN: 0cm 0cm 0pt"><SPAN lang=EN-GB><FONT
face="Times New Roman">However I still got stuck developing my spatial-object to
point-cloud registration.</FONT></SPAN></P>
<P class=MsoNormal style="MARGIN: 0cm 0cm 0pt"><SPAN lang=EN-GB><FONT
face="Times New Roman">I moved to another approach using a spatial object
(cylinder) and a point cloud generated by picking points in 3D within
vtk.</FONT></SPAN></P>
<P class=MsoNormal style="MARGIN: 0cm 0cm 0pt"><SPAN lang=EN-GB><FONT
face="Times New Roman"></FONT></SPAN> </P>
<P class=MsoNormal style="MARGIN: 0cm 0cm 0pt"><SPAN lang=EN-GB><FONT
face="Times New Roman">I convert the point cloud using itkPointSetToImageFilter,
getting a binary image of the point cloud, so I can plug it in the
model-to-image registration example from the itk book. However, when I look at
the resulting image volume within vtk, I get very strange pictures. I think that
is due to the parameters: spacing, origin and size, used for the
PointSetToImageFilter. This it what I thought it should be:</FONT></SPAN></P>
<P class=MsoNormal style="MARGIN: 0cm 0cm 0pt"><SPAN lang=EN-GB><FONT
face="Times New Roman"></FONT></SPAN> </P>
<P class=MsoNormal style="MARGIN: 0cm 0cm 0pt"><SPAN lang=EN-GB><FONT
face="Times New Roman">The volume within vtk I pick the points on is 50mm x 50mm
x 50mm. Originally the volume was represented by voxels of 0.25mm x 0.25mm x
0.5mm. </FONT></SPAN></P>
<P class=MsoNormal style="MARGIN: 0cm 0cm 0pt"><SPAN lang=EN-GB><FONT
face="Times New Roman">So this is why I choose the following size fore the
itkPointSetToImageFilter</FONT></SPAN></P>
<P class=MsoNormal style="MARGIN: 0cm 0cm 0pt"><FONT
face="Times New Roman">50mm/0.25 -> 200 pixel (x)</FONT></P>
<P class=MsoNormal style="MARGIN: 0cm 0cm 0pt"><FONT
face="Times New Roman">50mm/0.25 -> 200 pixel (y)</FONT></P>
<P class=MsoNormal style="MARGIN: 0cm 0cm 0pt"><SPAN lang=EN-GB><FONT
face="Times New Roman">50mm/0.25 -> 100 slices (z)</FONT></SPAN></P>
<P class=MsoNormal style="MARGIN: 0cm 0cm 0pt"><SPAN lang=EN-GB><FONT
face="Times New Roman">As for the spacing I took the spacing from the original
image volume</FONT></SPAN></P>
<P class=MsoNormal style="MARGIN: 0cm 0cm 0pt"><SPAN lang=EN-GB><FONT
face="Times New Roman">0.25 - 0.25 - 0.5.</FONT></SPAN></P>
<P class=MsoNormal style="MARGIN: 0cm 0cm 0pt"><SPAN lang=EN-GB><FONT
face="Times New Roman">The origin is defined as (0,0,0), indicating the lower
left corner of the volume. </FONT></SPAN></P>
<P class=MsoNormal style="MARGIN: 0cm 0cm 0pt"><SPAN lang=EN-GB><FONT
face="Times New Roman"></FONT></SPAN> </P>
<P class=MsoNormal style="MARGIN: 0cm 0cm 0pt"><SPAN lang=EN-GB><FONT
face="Times New Roman">Defining itkPointSetToImageFilter for the registration in
the way I did should result in a transformation I could transform directely
within my vtk-volume-space (hope so) !?</FONT></SPAN></P>
<P class=MsoNormal style="MARGIN: 0cm 0cm 0pt"><SPAN lang=EN-GB><FONT
face="Times New Roman"></FONT></SPAN> </P>
<P class=MsoNormal style="MARGIN: 0cm 0cm 0pt"><SPAN lang=EN-GB><FONT
face="Times New Roman">Unfortunately the filtering of the point cloud to an
image volume does not work as I expected. </FONT></SPAN></P>
<P class=MsoNormal style="MARGIN: 0cm 0cm 0pt"><SPAN lang=EN-GB><FONT
face="Times New Roman">Maybe someone used a similar approach and can show me how
to do it the right way?</FONT></SPAN></P>
<P class=MsoNormal style="MARGIN: 0cm 0cm 0pt"><SPAN lang=EN-GB><FONT
face="Times New Roman"></FONT></SPAN> </P>
<P class=MsoNormal style="MARGIN: 0cm 0cm 0pt"><SPAN lang=EN-GB><FONT
face="Times New Roman">Regards, Peter.</FONT></SPAN></P>
<P class=MsoNormal style="MARGIN: 0cm 0cm 0pt"><SPAN lang=EN-GB><FONT
face="Times New Roman"></FONT></SPAN> </P>
<P class=MsoNormal style="MARGIN: 0cm 0cm 0pt"><SPAN lang=EN-GB><FONT
face="Times New Roman">PS: does the cylinder spatial object respresents a filled
cylinder or does it represent an empty one?</FONT></SPAN></P></FONT></DIV>
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