<br>Hi Gen,<br><br><ol><li>As Cagatay pointed out, the Vesselness filter produces a scalar image<br>containing a "Vesselness" measure, which indicate how much every <br>pixel "looks like" being part of a Vessel. The filter is not intended to <br>
produce a binary image.<br>You could use the output of this filter as the input of a Thresholding<br>filter or the input of a region growing filter</li><li>The Sigma relates to the diameter of the Vessel that you are <br>
looking for. Larger sigmas will tune the filter for detecting larger vessels.<br>Please note that the units of Sigma in this filter are in physical units<br>(e.g. millimeters).</li><li>For good values of Alpha1 and Alpha2, please look at the LesionSizingToolkit<br>
<a href="http://public.kitware.com/LesionSizingKit/index.php/Main_Page">http://public.kitware.com/LesionSizingKit/index.php/Main_Page</a><br>It is based on ITK.<br>If you look at the subdirectory:<br>LesionSizingKit/Sandbox/Source/<br>
<br>You will find the file:<br>itkSatoVesselnessFeatureGenerator.h<br><br>The values we use there are:<br><br>Alpha1 = 0.1<br>Alpha2 = 2.0</li></ol><br><br> Regards,<br><br><br> Luis<br><br><br>---------------------------------------<br>
<div class="gmail_quote">On Sat, Feb 21, 2009 at 7:40 PM, Gen-Nan Chen <span dir="ltr"><<a href="mailto:gnchen@gmail.com">gnchen@gmail.com</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;">
Hi! All,<br><br>I tried to use Hessian3DToVesselnessMeasureImageFilter to segment vessel tree in the lung. I have a few questions here<br><br>1. The output Image of Hessian3DToVesselnessMeasureImageFilter is not a binary image as I thought. Can anyone tell me what those voxel value mean? Do I need to <br>
\<br>2. HessianRecursiveGaussianImageFilter's sigma. Anyone know what does this sigma value mean and for? Looks like I can get a biggger vessel by using a bigger sigma?<br><br>3. For thin tube like those vessels in the lung, what's the recommendation value for alph1 and alph2?<br clear="all">
<font color="#888888">
<br>-- <br>Gen-Nan Chen, <br>email: <a href="mailto:gnchen@gmail.com" target="_blank">gnchen@gmail.com</a><br>
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