<DIV>Hello Luis,</DIV>
<DIV> </DIV>
<DIV>What are the ITK filters other than Sigmoid that can be used to generate speed images?</DIV>
<DIV>In some cases, gradient magnitude + sidmoid filter is not helping me due to gaps produced on boundaries of gradient magnitude. This leads to leackage in the final output. </DIV>
<DIV> </DIV>
<DIV>Thanks,</DIV>
<DIV>Conn</DIV>
<DIV> </DIV>
<DIV><BR><BR><B><I>Luis Ibanez <luis.ibanez@kitware.com></I></B> wrote:</DIV>
<BLOCKQUOTE class=replbq style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #1010ff 2px solid"><BR><BR>Hi Conn,<BR><BR><BR>The speed image computation starts in :<BR><BR>Insight/Code/Algorithms/<BR>itkSegmentationLevelSetimageFilter.txx<BR><BR>The computation is delegated to the SegmentationFunction<BR>by invoking its method:<BR><BR>CalculateSpeedImage();<BR><BR>This method is implemented in the file<BR><BR>Insight/Code/Algorithms/<BR>itkCannySegmentationLevelSetFunction.txx<BR><BR>in lines 30-38.<BR><BR><BR>The speed image is computed as a distance map to the Canny<BR>edges in the method CalculateDistanceimage() in lines 81-102<BR>of the same file.<BR><BR><BR><BR><BR>Regards,<BR><BR><BR><BR>Luis<BR><BR><BR><BR>-----------------------------------------------------------------------------<BR>conn sullivan wrote:<BR><BR>> Hello Luiz,<BR>> <BR>> I appreciate your reply. I get the speed image now. I have one more <BR>> question. Are speed values taken directly from
these speed image. Also, <BR>> what is z(x) computed for canny edge filter. What part of code from <BR>> .cxx file performs this calculation?<BR>> <BR>> Thanks,<BR>> Conn.<BR>> <BR>> */Luis Ibanez <LUIS.IBANEZ@KITWARE.COM>/* wrote:<BR>> <BR>> <BR>> Hi Conn,<BR>> <BR>> <BR>> Thanks for posting the output of the two readers.<BR>> <BR>> We tracked this problem down and found that what you are missing is<BR>> to invoke the "GenerateSpeedImage()" method in the Canny level set<BR>> filter before you invoke GetSpeedImage().<BR>> <BR>> Note that the GenerateSpeedImage() method must be called after<BR>> runninig the filter with Update().<BR>> <BR>> <BR>> For your convinience we added this code to the example in<BR>> <BR>> Insight/Examples/Segmentation/<BR>> CannySegmentationLevelSetImageFilter.cxx<BR>> <BR>> <BR>> <BR>> In order to get the new version simply update your CVS checkout of ITK,<BR>> or
go to the CVS-Web portal and download the new version of this file:<BR>> <BR>> http://www.itk.org/cgi-bin/viewcvs.cgi/Examples/Segmentation/CannySegmentationLevelSetImageFilter.cxx?rev=1.27&root=Insight&view=log<BR>> <BR>> <BR>> <BR>> <BR>> Regards,<BR>> <BR>> <BR>> <BR>> Luis<BR>> <BR>> <BR><BR><BR><BR></BLOCKQUOTE><p>__________________________________________________<br>Do You Yahoo!?<br>Tired of spam? Yahoo! Mail has the best spam protection around <br>http://mail.yahoo.com