<div class="gmail_quote">On Fri, Oct 22, 2010 at 12:58 AM, Erik Türke <span dir="ltr"><<a href="mailto:tuerke@cbs.mpg.de">tuerke@cbs.mpg.de</a>></span> wrote:<br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
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Am 21.10.2010 19:17, schrieb Torsten Rohlfing:
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Hi guys -<br>
<br>
This is more of a question than a suggestion: does ITK currently
support "pixel padding"? That is, can we currently define a value
in the image data that serves as a marker for pixels that aren't
really there? Think of it as a binary mask coded into the image
itself.<br>
<br>
</div></blockquote><br>
Well i think extracting a region of interest which should be
considered during the registration is possible by passing a mask to
the image metric. So the challenge is to define this mask
automatically. I am first thinking of an Otsu filter to define such
a mask.<br>
A second possibility would be to use the "<a href="http://www.itk.org/Doxygen318/html/classitk_1_1ImageToImageMetric.html#ae56734d7cc4bb45a6ba462e56f260546" target="_blank">SetUseFixedImageSamplesIntensityThreshold</a>"
method or</div></blockquote><div><br><br>On that note, it appears that the Mattes metric in Review/ does not use this threshold when computing the bin size in its Initialize() method. There'd be a lot of bins in the joint histogram wasted needlessly.<br>
<br>Secondly its nice to have a pixel padding value option in the fixed/moving images. CT scans have with this value outside the gantry; typical values of ~32768. The above method would suffice for these scans, but its going to throw the binning off.<br>
<br>thx<br>--<br>karthik</div></div><br>