Hi Ella,<br><br>The Fast Marching Filter takes two inputs.<br><br> A) A list of set points<br><br>and <br><br> B) A speed image<br><br><br>The input (A) is required, while the input (B) is optional.<br>
<br><br>When (B) is not provided, the FastMarching filter assumes<br>that the a uniform speed field is to be used, and therefore<br>it computes the equivalent of a distance map to the set of<br>seed points.<br><br><br>What you need to pass as input to the GeodesicActiveContour<br>
filter is a level set image. Such input can be generated by the<br>FastMarching filter, among many other methods. If you choose<br>to use the FastMarching filter to generate the input of the <br>GeodesicActiveContour you should make sure that the zero<br>
set of the output in the FastMarching filter is close enough<br>to the shape that you are trying to segment.<br><br>One way to verify this is by thresholding the output of the<br>FastMarching and visualizing it with your favorite viewer<br>
program.<br><br><br> Luis<br><br><br>------------------------------------------<br><div class="gmail_quote">On Mon, Feb 14, 2011 at 8:33 AM, Ella Maria Kadas <span dir="ltr"><<a href="mailto:ella_kadas@yahoo.com">ella_kadas@yahoo.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;"><table border="0" cellpadding="0" cellspacing="0"><tbody><tr><td style="font: inherit;" valign="top">
I still don't really understand what does FastMarchingFilter get as input. I tried the FastMarchingFilter example from ITK/Segmentation and i don't see how providing only the output of the Sigmoid Filter and seed points i only get a black image.<div>
I tried to use the SignedDanielssonDistanceFilter and the Image that i get from it looks pretty good. so i used</div><div><p style="margin: 0px; font: 11px Menlo;"><br></p><p style="margin: 0px; font: 11px Menlo;"><br></p>
<p style="margin: 0px; font: 11px Menlo;"> smoothing-><span style="color: rgb(61, 35, 128);">SetInput</span>([<span style="color: rgb(81, 129, 135);">itkImage</span> <span style="color: rgb(51, 89, 93);">itkImporter</span>]->GetOutput() );</p>
<p style="margin: 0px; font: 11px Menlo;"><span style="white-space: pre-wrap;"> </span>gradientMagnitude-><span style="color: rgb(61, 35, 128);">SetInput</span>( smoothing->GetOutput() );</p>
<p style="margin: 0px; font: 11px Menlo;"><span style="white-space: pre-wrap;"> </span>sigmoid-><span style="color: rgb(61, 35, 128);">SetInput</span>( gradientMagnitude->GetOutput() );</p>
<p style="margin: 0px; font: 11px Menlo; min-height: 13px;"><span style="white-space: pre-wrap;"> </span></p>
<p style="margin: 0px; font: 11px Menlo;"><span style="white-space: pre-wrap;"> </span>geodesicActiveContour-><span style="color: rgb(61, 35, 128);">SetInput</span>( distanceMap->GetOutput() );</p>
<p style="margin: 0px; font: 11px Menlo;"><span style="white-space: pre-wrap;"> </span>geodesicActiveContour->SetFeatureImage( sigmoid->GetOutput() );</p>
<p style="margin: 0px; font: 11px Menlo; min-height: 13px;"><span style="white-space: pre-wrap;"> </span></p>
<p style="margin: 0px; font: 11px Menlo;"><span style="white-space: pre-wrap;"> </span>thresholder-><span style="color: rgb(61, 35, 128);">SetInput</span>( geodesicActiveContour->GetOutput() );</p><p style="margin: 0px; font: 11px Menlo;">
and update the threshold.</p><p style="margin: 0px; font: 11px Menlo;">But the result is still a black image. Any ideea what am i still doing so wrong.</p><p style="margin: 0px; font: 11px Menlo;">Thanks in advance,</p><p style="margin: 0px; font: 11px Menlo;">
Ella</p><div><br></div><div><br></div></div></td></tr></tbody></table><br><br>_____________________________________<br>
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