<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">I had a program which used larger values for the variance in the Canny edge filter algorithm. As I am updating the program to a newer version of the ITK library I had discovered that this is problematic with changes made in this algorithm. My observations can be observed with the Canny edge example program. With the following variance values I get the following:<br><br>~1 : good results<br>~2-4: warning of "itkGaussianOperator.txx", line 54 kernel being truncated. Results look plausible<br>~8+: the out put is an image full of nan (ugly!)<br><br>Looking at the CVS, and knowing I was using ITK version 2.8.1 or 3.0 before. I am really not sure where this problem came from. Perhaps there was a change to DiscreteGaussianImageFilter?<br><br>Any idea's why this class broke how I was using it?<div><br></div><div><div><div>Also the method CannyEdgeDetectionImageFilter::SetMaximumError has a small mistake in it.</div><div><br></div><div>if (m_Variance[i] != v)</div><div><br></div><div>should be:</div><div><br></div><div>if (m_MaximumError[i] != v)<br><br>Thank,<br>Brad</div></div><div><br></div><br><div apple-content-edited="true"><div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font face="Helvetica" size="3" style="font: normal normal normal 12px/normal Helvetica; ">========================================================</font></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font face="Helvetica" size="3" style="font: normal normal normal 12px/normal Helvetica; ">Bradley Lowekamp </font></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font face="Helvetica" size="3" style="font: normal normal normal 12px/normal Helvetica; ">Management Systems Designers Contractor for</font></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font face="Helvetica" size="3" style="font: normal normal normal 12px/normal Helvetica; ">Office of High Performance Computing and Communications</font></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font face="Helvetica" size="3" style="font: normal normal normal 12px/normal Helvetica; ">National Library of Medicine </font></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><font face="Helvetica" size="3" style="font: normal normal normal 12px/normal Helvetica; "><a href="mailto:blowekamp@mail.nih.gov">blowekamp@mail.nih.gov</a></font></div><div><br></div></div></div></div></div></body></html>