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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 type=cite class=cite 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>
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