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<p class=MsoNormal><span lang=EN-GB>Hi itk users,<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-GB><o:p> </o:p></span></p>
<p class=MsoNormal><span lang=EN-GB>I am trying to write an algorithm to trace
centre line of a tube shape in 3D CT image.<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-GB><o:p> </o:p></span></p>
<p class=MsoNormal><span lang=EN-GB>I am using the hessian matrix to get the
direction of the tube shape.<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-GB><o:p> </o:p></span></p>
<p class=MsoNormal><span lang=EN-GB>The Eigen values and vector of hessian
matrix for coordinate [9,5,2]:<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-GB><o:p> </o:p></span></p>
<p class=MsoNormal><span lang=EN-GB>Eigen value: -560.862 -1022.66
12.2557 (not in any order)<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-GB><o:p> </o:p></span></p>
<p class=MsoNormal>Eigen vectors: 0.701 0.708 0.078<o:p></o:p></p>
<p class=MsoNormal>
-0.702 0.705 -0.092<o:p></o:p></p>
<p class=MsoNormal> -0.120 0.010 0.992<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal><span lang=EN-GB>When arranged in |Lambda1| < |Lambda2|
< |Lambda3| , i get 12.2557 as Lambda1.<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-GB>If my understanding of literature is right,
then the direction of the tube centre line will<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-GB>point in the direction of eigenvector corresponding
to 12.2557 which is 0.992.<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-GB><o:p> </o:p></span></p>
<p class=MsoNormal><span lang=EN-GB>If i am right so far, then my question is :<o:p></o:p></span></p>
<p class=MsoListParagraph style='text-indent:-18.0pt;mso-list:l0 level1 lfo1'><![if !supportLists]><span
lang=EN-GB><span style='mso-list:Ignore'>1.<span style='font:7.0pt "Times New Roman"'>
</span></span></span><![endif]><span lang=EN-GB>how to calculate the next coordinate
to which i have to move from [9,5,2]?<o:p></o:p></span></p>
<p class=MsoListParagraph style='text-indent:-18.0pt;mso-list:l0 level1 lfo1'><![if !supportLists]><span
lang=EN-GB><span style='mso-list:Ignore'>2.<span style='font:7.0pt "Times New Roman"'>
</span></span></span><![endif]><span lang=EN-GB>Is there any literature to
refer to ?<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-GB> <o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-GB>Help to solve this problem will be highly
appreciated.<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-GB><o:p> </o:p></span></p>
<p class=MsoNormal><span lang=EN-GB>Thank you,<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-GB>Regards,<o:p></o:p></span></p>
<p class=MsoNormal>Kana<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
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