<p dir="ltr">Hi Roman,</p>
<p dir="ltr">This can be achieved with Fast Marching: the start front image will be your trial points, and the obstacle image the speed function (0.0 for obstacles, 1.0 for areas the front can expand).</p>
<p dir="ltr">You may be interested in the following Insight Journal publication: Fast Marching Minimal Path Extraction<br>
<a href="http://www.insight-journal.org/browse/publication/213">http://www.insight-journal.org/browse/publication/213</a></p>
<p dir="ltr">One of the examples shows how to extract a continuous directed path front a starting point and avoiding obstacles.</p>
<p dir="ltr">HTH</p>
<p dir="ltr">Cheers, Dan</p>
<div class="gmail_quote">On 16 Aug 2013 22:46, "Dr. Roman Grothausmann" <<a href="mailto:grothausmann.roman@mh-hannover.de">grothausmann.roman@mh-hannover.de</a>> wrote:<br type="attribution"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
Dear mailing list members,<br>
<br>
<br>
Starting with two binary images, I want to compute a distance-field image in a way that the first binary image is regarded as the start front and the second binary image represents obstacles in the way of the propagation front. From what I've read about similar problems either fast-marching or geodesic filters can supply the output I'm looking for.<br>
What itk-filter do I need for that? The itkReconstructionByDilationIma<u></u>geFilter seems only to take one input image although in the description a marker and a mask image are mentioned. The itkFastMarchingImageFilter seems to need a speed image, can that be constant, i.e. can it be the binary image containing the obstacles or would I have to supply a distance-map of the obstacle image?<br>
<br>
In a second step I'd like to normalize the absolute distance field image of the previous result. For that I want to supply a third binary image. The normalization should be done in a way that the abs. distance field image is adjusted such that it contains relative distance, i.e. between 0 and 1. The values of the abs. distance field should be adjusted such that the pixels of the shortest paths from any of the pixels making up the propagation start front to the finish front (contained in the third binary image) should linearly increase from 0 to 1. I'm not sure if this can be done because possibly the solution is not well/uniquely defined.<br>
Any ideas or comments on this are very welcome.<br>
<br>
Thanks for any help or hints<br>
Roman<br>
<br>
<br>
<br>
-- <br>
Dr. Roman Grothausmann<br>
<br>
Tomographie und Digitale Bildverarbeitung<br>
Tomography and Digital Image Analysis<br>
<br>
Institut für Funktionelle und Angewandte Anatomie, OE 4120<br>
Medizinische Hochschule Hannover<br>
Carl-Neuberg-Str. 1<br>
D-30625 Hannover<br>
<br>
Tel. <a href="tel:%2B49%20511%20532-9574" value="+495115329574" target="_blank">+49 511 532-9574</a><br>
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