<div dir="ltr">Yes, it is unclear. I always end up getting it wrong even though I wrote the current version. FYI, the requirement is not really necessary for the current implementation, and was kept for compatibility with the original (slow) version. My preference would be to produce a marker that was the pixelwise min of the marker and mask, hence avoiding this issue. Also note that it is the Vincent algorithm that is being used.<div>
<br></div><div style>It is possible that the error message is back to front. For a reconstruction by dilation the marker should be <= mask.</div><div style><br></div><div style>The convention is that the Marker image is dilated, and then masked by the mask image, so the marker is the one that needs to be <= for a reconstruction by dilation. In the opening by reconstruction the marker is an eroded version of the original (always <= original) and the mask is the original.</div>
<div><br></div><div> </div></div><div class="gmail_extra"><br><br><div class="gmail_quote">On Tue, May 21, 2013 at 4:35 PM, Thomas Deschamps <span dir="ltr"><<a href="mailto:tdeschamps@lbl.gov" target="_blank">tdeschamps@lbl.gov</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">Hi<br><br>In ITK ReconstructionByDilationImageFilter it's specifically written <a href="http://www.itk.org/Doxygen/html/classitk_1_1ReconstructionByDilationImageFilter.html" target="_blank">in the documentation</a> that The marker image must be less than or equal to the mask image (on a pixel by pixel basis).<br>
But in SimpleITK I get the following error message with sitk.ReconstructionByDilationImageFilter: <br><br><blockquote style="margin:0px 0px 0px 40px;border:none;padding:0px">itk::ERROR: ReconstructionByDilationImageFilter(0x7fd6fc671ea0): Marker pixels must be >= mask pixels.</blockquote>
<br>So either the message means that some marker pixels have been found to be >= to mask pixels, or another convention as been chosen. Does anybody know the answer?<div><br></div><div>BTW, it is clearly not indicated in the documentation which image is the marker image and which one is the mask image. Is this documented anywhere?</div>
<div><br></div><div>Thanks for your help.</div><span class="HOEnZb"><font color="#888888"><div><br>TD.</div><div><br></div></font></span></div>
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