That's much clearer now!<br>If your reader and cast filter are not in the same place (focus), <br>the smart pointer has deleted the reader. Now it's sure. The simplest<br>work around (but not the fanciest/cutest) would be:<br>
<br>reader->Update( );<br>vtkImagedata* readerOutput = vtkImageData::SafeDownCast( reader->GetOutputDataObject( 0, 0 ));<br>vtkImageData* myImage = vtkImageData::New( );<br>myImage->DeepCopy( readerOutput );<br><br>
Then you can use myImage everywhere you want. Don't forget to Delete( ) it, since it is not a SmartPointer but a simple New() allocation.<br><br>HTH<br>Jerome<br><br><br><div class="gmail_quote">2011/6/8 Laurent Mundeleer <span dir="ltr"><<a href="mailto:laurent.mundeleer@uclouvain.be">laurent.mundeleer@uclouvain.be</a>></span><br>
<blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">Hi Jerome,<br>
Thank you for your answer.<br>
<br>
The problem is that the reader and the cast are not done at the same<br>
place so that's why I have a vtkImageData which is transmitted in<br>
another parts of the code.<br>
I use a vtkImageData to have some informations such as dimensions,<br>
center, etc and because we use other types so we have sometimes to<br>
translate from vtkImageData to another image type (custom image types or<br>
QImage for instance).<br>
<br>
I understand I break the pipeline doing this as I have :<br>
reader->imageData | break<br>
imageData->cast->mapper-> etc<br>
instead of : reader->cast->mapper-> etc<br>
But if I want to keep the pipeline complete, I have to transmit a<br>
vtkAlgorithm pointer which is less usable outside of vtk, and actually I<br>
don't need the beginning of the pipeline, I have enough with the<br>
vtkImageData.<br>
<br>
Actually if I delete the reader pointer I have the same problem, so that<br>
means using the setInput() method as I do involves somewhere a call to<br>
myVtkImageData->GetProducerPort() which is became null...<br>
<br>
That means also I guess I can't use the same reader to read a lot of<br>
vtkImageData for instance (which would solve my leak problem), because<br>
somewhere it keeps a reference to the reader which has done the import<br>
in the vtkImageData.<br>
I can't imagine what happen if I read a first vtkImageData, and then a<br>
second, and try to display or apply a filter to the first one.<br>
<br>
Thanks,<br>
<font color="#888888"><br>
Laurent<br>
</font><div><div></div><div class="h5"><br>
On Wed, 2011-06-08 at 16:42 +0200, Jérôme wrote:<br>
> Hi,<br>
><br>
> You should use cast->SetInputConnection( reader->GetOutputPort( ) );<br>
> instead of the old fashion SetInput.<br>
> IMHO, the problem is that your smart pointer, for some reasons<br>
> (reference count becomes null), decided to deallocate the reader, and<br>
> thus the underlying output.<br>
><br>
> HTH,<br>
> Jerome<br>
><br>
> 2011/6/7 Laurent Mundeleer <<a href="mailto:laurent.mundeleer@uclouvain.be">laurent.mundeleer@uclouvain.be</a>><br>
> Hi everyone,<br>
> I have a strange problem in reading a MetaImage.<br>
> I have a segmentation fault when I access the vtkImageData,<br>
> but if I use a direct pointer instead of a smartPointer on the<br>
> vtkImageReader it's ok (but I have a memory leak).<br>
><br>
> What am I doing wrong ?<br>
> Here are some code extracts of what is working :<br>
><br>
> // in reader method :<br>
> ...<br>
> vtkImageData *imageData = 0;<br>
> ...<br>
><br>
> vtkMetaImageReader* reader = vtkMetaImageReader::New();<br>
> //add to replace : vtkSmartPointer<vtkMetaImageReader> reader<br>
> = vtkSmartPointer<vtkMetaImageReader>::New();<br>
> // and have no delete at the end of the reading<br>
> ..<br>
> reader->Update();<br>
> ...<br>
> imageData = reader->GetOutput();<br>
><br>
> // no delete on the reader<br>
><br>
> /------------------------------------------<br>
><br>
> // in renderer method :<br>
> vtkSmartPointer<vtkImageCast> castSource<br>
> =vtkSmartPointer<vtkImageCast>::New();<br>
> castSource->SetOutputScalarTypeToUnsignedChar();<br>
> castSource->SetInput(imageData); // seg fault<br>
> castSource->Update();<br>
><br>
> /---------------------------------------------<br>
> // or in unit test :<br>
> vtkImageData*volume = readingMethod();<br>
> ...<br>
> double *origin = volume->GetOrigin(); // seg fault<br>
><br>
><br>
> Thank you for any help,<br>
> Best Regards,<br>
><br>
> ++<br>
> Laurent<br>
><br>
><br>
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