<div dir="ltr">Thanks Karthik, I appreciate your help. It seems to be working at least in a simple test case.<div><br></div><div>The next step seems to be to get the WholeExtent of the data (so I can determine how to call SetUpdateExtent()). However, it seems I can't call GetWholeExtent() until after the Reader is updated? Ie, doing something like:<div style>
<div><div><span class="" style="white-space:pre"> </span>vtkSmartPointer<vtkXMLImageDataReader> reader = vtkSmartPointer<vtkXMLImageDataReader>::New();</div><div><span class="" style="white-space:pre"> </span>reader->SetFileName(inputFilename);</div>
<div><span class="" style="white-space:pre"> </span>reader->Update();</div><div><span class="" style="white-space:pre"> </span>int* we = reader->GetOutput()->GetWholeExtent();</div><div>defeats the purpose of a buffered read since the whole file is read.</div>
</div><div><br></div><div style>I was looking for a higher level method, but do I need to read the 'WholeExtent' attribute from the 'ImageData' XML element directly (ie, interact with the XML parser at a lower level)? Pardon me if I am missing something obvious.</div>
</div><div style><div><br></div><div><br></div></div></div></div><div class="gmail_extra"><br><br><div class="gmail_quote">On Tue, Apr 9, 2013 at 1:56 AM, Karthik Krishnan <span dir="ltr"><<a href="mailto:karthik.krishnan@kitware.com" target="_blank">karthik.krishnan@kitware.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">You can do a buffered reading with VTK xml image formats since a while in VTK, including 5.8... here's how. Turn off whole slices and set the update extent on the output.<div>
<br></div><div><span style="font-family:arial,sans-serif;font-size:16px">vtkXMLImageDataReader</span><span style="font-family:arial,sans-serif;font-size:16px"> *</span><span style="font-family:arial,sans-serif;font-size:16px">reader</span><span style="font-family:arial,sans-serif;font-size:16px"> = </span><span style="font-family:arial,sans-serif;font-size:16px">vtkXMLImageDataReader</span><span style="font-family:arial,sans-serif;font-size:16px">::New();</span><br style="font-family:arial,sans-serif;font-size:16px">
<span style="font-family:arial,sans-serif;font-size:16px">reader</span><span style="font-family:arial,sans-serif;font-size:16px">->SetFileName( "in.vti" );</span><br style="font-family:arial,sans-serif;font-size:16px">
<span style="font-family:arial,sans-serif;font-size:16px">reader</span><span style="font-family:arial,sans-serif;font-size:16px">->GetOutput()-></span><span style="font-family:arial,sans-serif;font-size:16px">SetUpdateExtent( 0, 799, 0, 599, 0, 499 );</span><br style="font-family:arial,sans-serif;font-size:16px">
<span style="font-family:arial,sans-serif;font-size:16px">reader</span><span style="font-family:arial,sans-serif;font-size:16px">->SetWholeSlices(0);</span><br style="font-family:arial,sans-serif;font-size:16px">
<span style="font-family:arial,sans-serif;font-size:16px">reader</span><span style="font-family:arial,sans-serif;font-size:16px">->Update();</span><br></div><div><span style="font-family:arial,sans-serif;font-size:16px"><br>
</span></div><div><font face="arial, sans-serif"><span style="font-size:16px">--</span></font></div><div><font face="arial, sans-serif"><span style="font-size:16px">karthik</span></font></div></div><div class="gmail_extra">
<br><br><div class="gmail_quote"><div><div class="h5">On Thu, Apr 4, 2013 at 8:10 PM, Kevin H. Hobbs <span dir="ltr"><<a href="mailto:hobbsk@ohio.edu" target="_blank">hobbsk@ohio.edu</a>></span> wrote:<br></div></div>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div><div class="h5">
<div>On 04/02/2013 08:52 PM, Grant McAuley wrote:<br>
> Ok, it seems that using vktXMLImageReader::SetUpdateExtent(int<br>
> extent[6]) requires vtk 6.0 ??? Unless I am missing something, the 5.10<br>
> docs show a SetUpdateExtent() method only available in data classes (as<br>
> a member of vtkDataObject) but not eg vtkXMLImageReader. I am using<br>
> 5.8, but could try 6.0.<br>
><br>
<br>
</div>Looks like you're right. SetUpdateExtent is defined in vtkAlgorithm in<br>
6.0 and not in 5.8.<br>
<br>
I've never set the extent on a reader anyway. I always do what I<br>
suggested in the first place:<br>
<br>
reader -> clip -> whatever<br>
^<br>
[extent]<br>
<br>
<br>
<br>
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<br></blockquote></div><span class="HOEnZb"><font color="#888888"><br><br clear="all"><div><br></div>-- <br>karthik
</font></span></div>
</blockquote></div><br><br clear="all"><div><br></div>-- <br>Grant McAuley<div>Postdoctoral Fellow</div><div>Radiation Research Labs</div><div>Radiation Medicine</div><div>Loma Linda University</div><div>(909) 558-1000 Ext 85173</div>
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