<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div>Chapter 8 of the ITK Software Guide describes the registration framework in great detail (diagrams included!): <a href="http://www.itk.org/ItkSoftwareGuide.pdf">http://www.itk.org/ItkSoftwareGuide.pdf</a></div><div><br></div><div><div>On Sep 29, 2009, at 9:00 AM, kevin cavin wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><table cellspacing="0" cellpadding="0" border="0"><tbody><tr><td valign="top" style="font: inherit;">Hi, Markus: <br><br> Thanks for your reply. what your explanation is clear. Actually the reason I ask this question is just because I found that If I change the two images ( fixed and moving ) I could obtain different results. Therefore I come up the question. <br><br> It seems for me that if you want register one image with another one, and if you do not want the orginal one is modified , the you should set that one as fixed since the moving image will be resampled and interpolated. But sometime it seems that setting the orginal image as fixed image can not get registeration result as good as it has been set as moving image. <br><br> Maybe you have some extra thought about that. <br><br><br>Kind regards <br><br>calvin <br><br><br><br><br>--- On <b>Tue, 9/29/09, Markus Neuner <i><<a href="mailto:neuner.markus@gmx.net">neuner.markus@gmx.net</a>></i></b> wrote:<br><blockquote style="border-left: 2px solid rgb(16, 16, 255); margin-left: 5px; padding-left: 5px;"><br>From: Markus Neuner <<a href="mailto:neuner.markus@gmx.net">neuner.markus@gmx.net</a>><br>Subject: Re: [Insight-users] fixed and moving image<br>To: "kevin cavin" <<a href="mailto:beibeiwen2003@yahoo.com">beibeiwen2003@yahoo.com</a>><br>Cc: <a href="mailto:insight-users@itk.org">insight-users@itk.org</a><br>Date: Tuesday, September 29, 2009, 8:13 PM<br><br><div class="plainMail">Hi Calvin,<br><br>In general the goal of registration is to find the transform that will bring a moving image into alignment with a fixed image based on the used registration criteria (maximize/minimize).<br>The transform maps points from the fixed image space to the moving image space.<br><br>Fixed image:<br>One or more fixed images are the reference of registration. It remains unchanged. The moving image is registered to match the fixed image.<br><br>Moving image:<br>The moving image is re-sampled to match the fixed image. Interpolation is performed in the moving image.<br><br>Which image is used as fixed and moving image heavily depends on the application. What images do you register (Size, Spacing, ...), and what is the desired goal of your registration?<br>If you change the two images you could obtain different results, especially when the spacings/sizes of th e images differ.<br><br><br>Best Regards,<br>Markus<br><br><br><br><br>kevin cavin wrote:<br>> Hello,<br>> <br>> I am working with ITK at this moment. I have one question regarding the selection of fixed and moving images. Does it matter that which one is fixed and which one is moving. Are there any rules for that? I noticed normally the moving image will be interpolated. Thanks !<br>> <br>> <br>> sincerely<br>> <br>> calvin<br>> <br>> <br>> <br></div></blockquote></td></tr></tbody></table><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: http://www.itk.org/Wiki/ITK_FAQ<br><br>Follow this link to subscribe/unsubscribe:<br>http://www.itk.org/mailman/listinfo/insight-users<br></blockquote></div><br></body></html>