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and what about Similarity2dTransform and AffineTransform??<BR>
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what are teh differences??<BR><BR>
Thanks!<BR>
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Date: Tue, 14 Jul 2009 12:02:21 -0400<BR>From: luis.ibanez@kitware.com<BR>To: mort.motes@gmail.com<BR>CC: insight-users@itk.org<BR>Subject: Re: [Insight-users] RigidTransform vs AffineTransform?<BR><BR><BR><BR>Hi Motes:<BR><BR><BR> A Rigid Transforms is not<BR> just an Affine centered Transform.<BR><BR><BR>1) A Rigid Transform supports:<BR> Translations and Rotations<BR><BR>2) An Affine Transform supports:<BR> Translations, Rotations, Scaling and Shearing.<BR><BR><BR>In ITK, both the Rigid and Affine transforms are "centered".<BR>Which means that you can specify what point of space should<BR>be used as the center of rotations.<BR><BR><BR>Yes, there is something unique that is accomplished by using<BR>a Rigid Transform:<BR><BR><BR> Managing Translations and Rotations, by only optimizing<BR> in an space of Six dimensions, instead of the space of <BR> 12 dimensions where you have to optimize an Affine Transform.<BR> (this for the case of 3D images).<BR><BR><BR><BR> Regards,<BR><BR><BR> Luis<BR><BR><BR>--------------------------------------------------------------------------------------------<BR>
<DIV class=EC_gmail_quote>On Sun, Jul 12, 2009 at 3:14 PM, motes motes <SPAN dir=ltr><<A href="mailto:mort.motes@gmail.com">mort.motes@gmail.com</A>></SPAN> wrote:<BR>
<BLOCKQUOTE class=EC_gmail_quote style="PADDING-LEFT: 1ex">In the itkSoftwareGuide an examples is walked through using a RigidTransform. But is a RigidTransform not just a centered AffineTransform? I am a bit confused that a RigidTransform exists, as I understand rigid and non-rigid are concepts that includes transforms. Something like:<BR><BR>Rigid:<BR> - Translation<BR> - Affine<BR><BR>Non-Rigid<BR> - BsplineDeformableTransform<BR><BR><BR>Or are there something unique about a RigidTransform that is not accomplished using eg. translation or Affine transforms?<BR><BR>_____________________________________<BR>Powered by <A href="http://www.kitware.com/">www.kitware.com</A><BR><BR>Visit other Kitware open-source projects at<BR><A href="http://www.kitware.com/opensource/opensource.html">http://www.kitware.com/opensource/opensource.html</A><BR><BR>Please keep messages on-topic and check the ITK FAQ at: <A href="http://www.itk.org/Wiki/ITK_FAQ">http://www.itk.org/Wiki/ITK_FAQ</A><BR><BR>Follow this link to subscribe/unsubscribe:<BR><A href="http://www.itk.org/mailman/listinfo/insight-users">http://www.itk.org/mailman/listinfo/insight-users</A><BR><BR></BLOCKQUOTE></DIV><BR><br /><hr />Charlas más divertidas con el nuevo <a href='http://download.live.com' target='_new'>Windows Live Messenger</a></body>
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