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<DIV><SPAN class=560193915-17102002><FONT color=#0000ff size=2>After adding
another to my pipeline (to flip and image), it appears that some filter
is not </FONT></SPAN></DIV>
<DIV><SPAN class=560193915-17102002><FONT color=#0000ff size=2>passing the
spacing and origin through. Once I track this down, I'll verify whether
this was the cause</FONT></SPAN></DIV>
<DIV><SPAN class=560193915-17102002><FONT color=#0000ff size=2>of my original
problem.</FONT></SPAN></DIV>
<DIV><SPAN class=560193915-17102002><FONT color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=560193915-17102002><FONT color=#0000ff
size=2></FONT></SPAN> </DIV>
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<DIV class=OutlookMessageHeader dir=ltr align=left><FONT face=Tahoma
size=2>-----Original Message-----<BR><B>From:</B> Lisa S. Avila
[mailto:lisa.avila@kitware.com]<BR><B>Sent:</B> Thursday, October 17, 2002
10:02 AM<BR><B>To:</B> Miller, James V (Research); Vtk Developers
(E-mail)<BR><B>Subject:</B> Re: [vtk-developers] Should
ImageViewer2/ImageActor using "Spacing"<BR><BR></FONT></DIV>Hello
Jim,<BR><BR>vtkImageActor does take into account the spacing of the image. How
is this being lost in the vtkImageView2?<BR><BR>Lisa<BR><BR><BR><BR>At 09:04
AM 10/17/2002, Miller, James V (Research) wrote:<BR>
<BLOCKQUOTE class=cite cite="" type="cite"><FONT size=2>I spent a few hours
last night tracking down a problem with my use of ImageViewer2. Since
ImageViewer2 uses the 3D rendering pipeline, I was tricked into thinking it
would be trivial to use the ImageViewer2 to show an intensity image and I
could simple add another actor to the ImageViewer2's renderer to display a
segmentation overlaid on the intensity image. The segmentation
technique uses level sets so I used Marching Squares to extract the zero set
as PolyData to overlay on the image. </FONT><BR> <BR><FONT
size=2>Now, the output of Marching Squares did not line up properly with the
original image. I believe the issue is that Marching Squares took into
account the data spacing while the ImageViewer2/ImageActor combination does
not take into account the data spacing.</FONT><BR> <BR><FONT size=2>I
know that we have struggled with this in the past, but should the ImageActor
use the pixel spacing to determine the "bounds" (and hence the projection)
of the image? 'Course sometimes you do want to view an image as if the
pixels were isotropic or unit size. Perhaps it could be a mode to turn
on/off pixel spacing.</FONT><BR> <BR><FONT size=2>I has a number of
options to get around this issue, scaling my polydata actor, using
ImageChangeInformation, etc. so it wasn't too hard to get around.
However, it did take me awhile to determine the use and lack of use of the
data spacing was what was causing my grief (I had assumed the problem was
with my multi-resolution scale space, not with the
rendering...)</FONT><BR><BR> <?xml:namespace prefix = o ns =
"urn:schemas-microsoft-com:office:office" /><BR><BR><B>Jim Miller</B>
<BR><B><I>_____________________________________</I></B><BR><I>Visualization
& Computer Vision<BR>GE Research</I><BR><I>Bldg. KW, Room
C218B</I><BR><I>P.O. Box 8, Schenectady NY 12301</I><BR><BR><I><U><A
href="mailto:millerjv@research.ge.com">millerjv@research.ge.com</A><BR></U></I><BR><I><U>james.miller@research.ge.com</U></I><BR><I>(518)
387-4005, Dial Comm: 8*833-4005, </I><BR><I>Cell: (518) 505-7065, Fax: (518)
387-6981</I> <BR><BR> <BR> </BLOCKQUOTE></BLOCKQUOTE></BODY></HTML>