[vtkusers] Problems to save snapshots of a vtk window

[Valérie Duay]

Hi,

I use a vtk window to visualize the iterations (image + contours) of my 
itk filter. This window works well. Now I would like to save a snapshot 
of this window at each iteration. I try to do this with 
vtkWindowToImageFilter but I get many problems.

1.	It can save only the first iteration and not the following ones. If I 
use winToIm->Modified(), the program crashes at the first iteration.
2.	It can save the first iteration only if I have an image or contours 
in the window but not both. Otherwise the program crashes at the first 
iteration.

//I define that outside the function SaveWindow()
vtkWindowToImageFilter *winToIm = vtkWindowToImageFilter::New();
winToIm->SetInput(renWin);
vtkJPEGWriter *jpgWriter = vtkJPEGWriter::New();

//The function SaveWindow is called at each iteration
void SaveWindow()
{
//winToIm->Modified(); =>Bug
	jpgWriter->SetInput( winToIm->GetOutput() );
	jpgWriter->SetQuality( 100 );
	jpgWriter->SetFileName( "image.jpg" );
	jpgWriter->ProgressiveOff();
	jpgWriter->Write();
}


//I have the following code to visualize the image and contour together 
on the same window
ren->AddActor(imageActor);
ren->AddProp(targetContourActor);

renWin->AddRenderer(ren);
renWin->SetSize(DisplayWinSize,DisplayWinSize);
renWin->Modified();
renWin->Render();

How should I do that?

Thanks in advance for your help,

Valerie