<div class="gmail_quote">On Tue, Feb 3, 2009 at 10:26 AM, Yogish Mallya <span dir="ltr"><<a href="mailto:mallyayogish@yahoo.co.in">mallyayogish@yahoo.co.in</a>></span> wrote:<br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<table border="0" cellpadding="0" cellspacing="0"><tbody><tr><td style="font-family: inherit; font-style: inherit; font-variant: inherit; font-weight: inherit; font-size: inherit; line-height: inherit; font-size-adjust: inherit; font-stretch: inherit;" valign="top">
<div>Dear Karthik,</div>
<div> </div>
<div>I have attached an image in the mail to give you further clarifications on the problem. I want to warp contour B on to contour A </div>
<div> </div>
<div>I gone through some of the publications on robust point matching. Looks like point matching technique may be overkill for my problem. I was wondering can't we use ordering of the points for both the contour ? Is there any functionality to fit b-spline functions to these two contours and then evaluate at different points for estimating deformation ?</div>
</td></tr></tbody></table></blockquote><div><br>You can certainly fit a BSpline curve / bezier curve etc to the two point sets. <br><br>The classes to do so are (vtkBezierContourLineInterpolator / itkBSplineScatteredDataPointSetToImageFilter)<br>
<br>However, by volunteering to take the approach of sampling the two curves you'll be assuming that the sample points do form a good point correspondance:<br><br>You can then use TPS or one of the other kernel splines in ITK to find the transform that maps .<br>
<br>-------<br><br>Are you sure RPM is an overkill for your problem ? I doubt if the algorithm will mess up your point ordering. <br><br>RPM (vtkpxTPSRPMRegistration) class minimizes<br>- Distance between the deformed (TPS) points and the target point set<br>
- magnitude of affine + magnitude of non-rigid component of the TPS (regularization).<br><br>The latter will be high if point ordering is messed up (the curve loops over itself etc).<br><br></div><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<table border="0" cellpadding="0" cellspacing="0"><tbody><tr><td style="font-family: inherit; font-style: inherit; font-variant: inherit; font-weight: inherit; font-size: inherit; line-height: inherit; font-size-adjust: inherit; font-stretch: inherit;" valign="top">
<div></div>
<div> </div>
<div>Thanks in advance</div><div class="Ih2E3d">
<div>Yogish<br><br>--- On <b>Tue, 3/2/09, Karthik Krishnan <i><<a href="mailto:karthik.krishnan@kitware.com" target="_blank">karthik.krishnan@kitware.com</a>></i></b> wrote:<br></div>
</div><blockquote style="border-left: 2px solid rgb(16, 16, 255); padding-left: 5px; margin-left: 5px;"><div class="Ih2E3d">From: Karthik Krishnan <<a href="mailto:karthik.krishnan@kitware.com" target="_blank">karthik.krishnan@kitware.com</a>><br>
Subject: Re: [Insight-users] aligning two contoursets<br>To: <a href="mailto:mallyayogish@yahoo.co.in" target="_blank">mallyayogish@yahoo.co.in</a><br>Cc: <a href="mailto:insight-users@itk.org" target="_blank">insight-users@itk.org</a><br>
Date: Tuesday, 3 February, 2009, 9:10 AM<br><br></div><div><div></div><div class="Wj3C7c"><pre>Yogish:
You should take a look at the Robust Point Matching algorithm from Chui and
Anand Rangarajan:
H. Chui and Anand Rangarajan, "A new algorithm for non-rigid point
matching", CVPR, 00
It solves the alignment problem with both rigid and non-rigid variants for
arbitrary number of source and target points, with point correspondances being
unknown. It is also fairly resilient to outliers. If you are looking for readily
available source code, its available as a part of the BioImageSuite, in the form
of a VTK algorithm. Look for source files of hte form vtk*RPM* and produces a
vtkTransform for you.
-- Karthik Krishnan
R & D Engineer,
Kitware Inc,
Ph: 518 371 3971 x119
Fax: 518 371 3971
Yogish Mallya wrote:
> Hi,
>
> I have to write an application in which I need to align two contours
(open)having different number of control points. In other words one of the
contours has more number of points compared to other. Is there any class in ITK
to warp a contour on to another?
>
> Best Wishes
> Yogish
>
>
> ------------------------------------------------------------------------
> Unlimited freedom, unlimited storage. Get it now
<<a href="http://in.rd.yahoo.com/tagline_mail_2/*http://help.yahoo.com/l/in/yahoo/mail/yahoomail/tools/tools-08.html/" target="_blank">http://in.rd.yahoo.com/tagline_mail_2/*http://help.yahoo.com/l/in/yahoo/mail/yahoomail/tools/tools-08.html/</a>>
> ------------------------------------------------------------------------
>
> _______________________________________________
> Insight-users mailing list
> <a href="mailto:Insight-users@itk.org" target="_blank">Insight-users@itk.org</a>
> <a href="http://www.itk.org/mailman/listinfo/insight-users" target="_blank">http://www.itk.org/mailman/listinfo/insight-users</a>
>
</pre></div></div></blockquote></td></tr></tbody></table><br>
<hr size="1"> Add more friends to your messenger and enjoy! <a href="http://in.rd.yahoo.com/tagline_messenger_6/*http://messenger.yahoo.com/invite/" target="_blank"> Invite them now.</a></blockquote></div><br><br clear="all">
<br>-- <br>Karthik Krishnan<br>R&D Engineer,<br>Kitware Inc.<br>Ph: 518 371 3971 x119<br>Fax: 518 371 3971<br>