<div class="gmail_quote"><br>Hi Wen,<br><br>Thanks for the clarification.<br><br>If the images look fine after visual inspection,<br>we probably can discard the sub-sampling from<br>the list of suspects.<br><br>It is more likely that the problem is in the <br>
configuration of your image registration <br>process.<br><br><br>Tell us more about the registration:<br><br><br>What components are you using ?<br><br> 1) Image modality ?<br> 2) Transform ?<br> 3) Optimizer ?<br> 4) Metric ?<br>
5) Interpolator ?<br><br><br>Have you connected an Observer to it ?<br><br>How many iterations is running ?<br><br><br>Does it produces any error messages ?<br><br>How are you initializing the Transform parameters ?<br>
<br>
Have you set the OptimizerScales ?<br>
If so, to what values ?<br>
<br>
<br><br> Thanks<br><br><br> Luis<br><br><br>------------------------------------------<div><div></div><div class="h5"><br><div class="gmail_quote">On Fri, Jul 10, 2009 at 10:36 AM, kevin cavin <span dir="ltr"><<a href="mailto:beibeiwen2003@yahoo.com" target="_blank">beibeiwen2003@yahoo.com</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>Hello, Luis: </div>
<div> </div>
<div> I immdiate show the down sampling result after the down sampling . the images of the volume are just half smaller, which look good. I do not whether the bad registeration result come from low resolution of the volumes. Do you have any experiences with that ? Thanks ! </div>
<div> </div>
<div>Kind regards </div>
<div> </div>
<div>Wen</div>
<div> </div>
<div> </div>
<div><br><br>--- On <b>Fri, 7/10/09, Luis Ibanez <i><<a href="mailto:luis.ibanez@kitware.com" target="_blank">luis.ibanez@kitware.com</a>></i></b> wrote:<br></div>
<blockquote style="border-left: 2px solid rgb(16, 16, 255); padding-left: 5px; margin-left: 5px;"><br>From: Luis Ibanez <<a href="mailto:luis.ibanez@kitware.com" target="_blank">luis.ibanez@kitware.com</a>><br>Subject: Re: [Insight-developers] down sampling<br>
To: "kevin cavin" <<a href="mailto:beibeiwen2003@yahoo.com" target="_blank">beibeiwen2003@yahoo.com</a>><br>Cc: <a href="mailto:Insight-developers@itk.org" target="_blank">Insight-developers@itk.org</a>, "itk" <<a href="mailto:Insight-users@itk.org" target="_blank">Insight-users@itk.org</a>><br>
Date: Friday, July 10, 2009, 10:07 PM<div><div></div><div><br><br>
<div><br>Hi Kevin,<br><br>Have you saved the images just after down-sampling<br>and looked at them ?<br><br><br>How do they look ?<br><br><br>Please let us know,<br><br><br>------<br><br>BTW: Please submit questions to the itk-users list.<br>
The Developers list is dedicated to discussions related<br>to code added to ITK or modifications to ITK code.<br><br><br> Thanks<br><br><br> Luis<br><br><br>----------------------------------------------------------------------------------<br>
<div class="gmail_quote">On Fri, Jul 10, 2009 at 9:19 AM, kevin cavin <span dir="ltr"><<a href="http://us.mc347.mail.yahoo.com/mc/compose?to=beibeiwen2003@yahoo.com" rel="nofollow" target="_blank">beibeiwen2003@yahoo.com</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">
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<div>Hello, </div>
<div> </div>
<div> I am using Resamplefilter to downsampling my 3D volume in order to register two volumes. Without downsampling and with less slices , I get two volume registered. With downsampling, the registered result is non sense (empty image). I am woderning where goes wrong? Maybe somepeople can help me. Thanks!</div>
<div> </div>
<div>wen </div>
<div> </div>
<div> I attach part of code </div>
<div> </div>
<div>factorX = 2<br>factorY = 2<br>factorZ = 1</div>
<div>inputSpacing1 = windowing1.GetOutput().GetSpacing()<br>inputSpacing2 = windowing2.GetOutput().GetSpacing()<br>resampler1 =itk.ResampleImageFilter.IF3IF3.New()<br>resampler2 =itk.ResampleImageFilter.IF3IF3.New()</div>
<div>transform=itk.IdentityTransform.D3.New()<br>transform.SetIdentity()<br>resampler1.SetTransform( transform.GetPointer() )<br>resampler2.SetTransform( transform.GetPointer() )</div>
<div>interpolator1=itk.LinearInterpolateImageFunction.IF3D.New()<br>resampler1.SetInterpolator( interpolator1.GetPointer() )<br>resampler1.SetDefaultPixelValue( 0 )</div>
<div><br>interpolator2=itk.LinearInterpolateImageFunction.IF3D.New()<br>resampler2.SetInterpolator( interpolator2.GetPointer() )<br>resampler2.SetDefaultPixelValue( 0 )</div>
<div><br>spacing1=itk.Vector.D3()<br>spacing2=itk.Vector.D3()</div>
<div><br>spacing1.SetElement(0,inputSpacing1.GetElement(0) * factorX)<br>spacing1.SetElement(1,inputSpacing1.GetElement(1) * factorY)<br>spacing1.SetElement(2,inputSpacing1.GetElement(2) * factorZ)</div>
<div>spacing2.SetElement(0,inputSpacing2.GetElement(0) * factorX)<br>spacing2.SetElement(1,inputSpacing2.GetElement(1) * factorY)<br>spacing2.SetElement(2,inputSpacing2.GetElement(2) * factorZ)</div>
<div><br>resampler1.SetOutputSpacing( spacing1 )<br>resampler1.SetOutputOrigin( windowing1.GetOutput().GetOrigin() )<br>resampler1.SetOutputDirection( windowing1.GetOutput().GetDirection() )</div>
<div>resampler2.SetOutputSpacing( spacing2 )<br>resampler2.SetOutputOrigin( windowing2.GetOutput().GetOrigin() )<br>resampler2.SetOutputDirection( windowing2.GetOutput().GetDirection() )</div>
<div><br>inputSize= windowing1.GetOutput().GetLargestPossibleRegion().GetSize()</div>
<div>print "X size : %f" % (inputSize.GetElement(0), )<br>print "Y size : %f" % (inputSize.GetElement(1), )<br>print "Z size : %f" % (inputSize.GetElement(2), )</div>
<div>size=itk.FixedArray.D3()</div>
<div>new_x=inputSize.GetElement(0)/factorX<br>new_y=inputSize.GetElement(1)/factorY<br>new_z=inputSize.GetElement(2)/factorZ </div>
<div><br>inputSize.SetElement(0, int(new_x))<br>inputSize.SetElement(1, int(new_y))<br>inputSize.SetElement(2, int(new_z))</div>
<div>resampler1.SetSize( inputSize )<br>resampler1.SetInput( windowing1.GetOutput() )</div>
<div>resampler2.SetSize( inputSize )<br>resampler2.SetInput( windowing2.GetOutput() )<br></div></td></tr></tbody></table><br><br>_______________________________________________<br>Powered by <a href="http://www.kitware.com/" rel="nofollow" target="_blank">www.kitware.com</a><br>
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