<br>Hi Erik,<br><br>We may have to search for the Nifti gurus...<br><br>or even post the question to the Nifti mailing list...<br><br> <a href="http://nifti.nimh.nih.gov/board/list.php?f=1">http://nifti.nimh.nih.gov/board/list.php?f=1</a><br>
<br><br>In the meantime, <br>the CVS commit logs may give us some hints.<br><br>For example:<br><br><a href="http://public.kitware.com/cgi-bin/viewcvs.cgi/Code/IO/itkNiftiImageIO.cxx?root=Insight&r1=1.77&r2=1.78">http://public.kitware.com/cgi-bin/viewcvs.cgi/Code/IO/itkNiftiImageIO.cxx?root=Insight&r1=1.77&r2=1.78</a><br>
<br>Indicates that the "if" checks were added recently.<br><br><br>and <br><br><a href="http://public.kitware.com/cgi-bin/viewcvs.cgi/Code/IO/itkNiftiImageIO.cxx?root=Insight&r1=1.48&r2=1.49">http://public.kitware.com/cgi-bin/viewcvs.cgi/Code/IO/itkNiftiImageIO.cxx?root=Insight&r1=1.48&r2=1.49</a><br>
<br>says that<br><br>"ENH: When reading in NIfTI files, preserve rotation information from header instead of setting Dir Cosines to the nearest canonical orientation"<br><br><br>I would guess that you concern is more about the<br>
minus sign in the [1] direction, than about the<br>"if" conditions. Is that right ?<br><br><br>Please let us know<br><br><br> Thanks<br><br><br> Luis<br> <br><br>-----------------------------------------------------------------------------------------------<br>
<div class="gmail_quote">On Tue, Apr 13, 2010 at 2:51 PM, Erik Tuerke <span dir="ltr"><<a href="mailto:tuerke@cbs.mpg.de">tuerke@cbs.mpg.de</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;">
Hi<br>
<br>
In the itkNiftiImageIO.cxx i discovered something what is kind of inconclusively to me.<br>
<br>
line 1533, itk version 3.16<br>
<br>
m_Origin[0] = -theMat.m[0][3];<br>
if(dims > 1)<br>
{<br>
m_Origin[1] = -theMat.m[1][3];<br>
}<br>
if(dims > 2)<br>
{<br>
m_Origin[2] = theMat.m[2][3];<br>
}<br>
<br>
When writing a nifti file from an external source (not red by the itkImageFileReader), i noticed different orientation in both the input image (which was red by a not-itk-reader) and the output image (what was written by an itk-writer).<br>
When reading the image with the itkReader this difference does not occur. So i think those negation is done by the reader as well (unfortunately did not find the code for this, yet).<br>
What is the sense of this? Why is itk internally using different orientation then stored in the file?<br>
<br>
Thanks in advance<br>
<br>
cheers<br>
<br>
--<br>
Erik Türke<br>
Department of Neurophysics<br>
Max-Planck-Institute for Human Cognitive and Brain Sciences<br>
Stephanstrasse 1A<br>
04103 Leipzig<br>
Germany<br>
Tel: +49 341 99 40-2440<br>
Email: <a href="mailto:tuerke@cbs.mpg.de">tuerke@cbs.mpg.de</a><br>
<a href="http://www.cbs.mpg.de" target="_blank">www.cbs.mpg.de</a><br>
<br>
<br>
_____________________________________<br>
Powered by <a href="http://www.kitware.com" target="_blank">www.kitware.com</a><br>
<br>
Visit other Kitware open-source projects at<br>
<a href="http://www.kitware.com/opensource/opensource.html" target="_blank">http://www.kitware.com/opensource/opensource.html</a><br>
<br>
Kitware offers ITK Training Courses, for more information visit:<br>
<a href="http://www.kitware.com/products/protraining.html" target="_blank">http://www.kitware.com/products/protraining.html</a><br>
<br>
Please keep messages on-topic and check the ITK FAQ at:<br>
<a href="http://www.itk.org/Wiki/ITK_FAQ" target="_blank">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" target="_blank">http://www.itk.org/mailman/listinfo/insight-users</a><br>
</blockquote></div><br>