[Insight-users] How to watch IterationEvent()

[jiang]

Hi, ITK users,
I use itk::ThresholdSegmentationLevelSetImageFilter to do segmentation as
the example application ThresholdSegmentationLevelSetFltkGui.
I use Qt as user interface. Learning from example QtITK, I use the following
code to watch IterationEvent().

	ThresholdSegmentationLevelSetImageFilterType::Pointer m_Filter;
	m_Filter=ls->GetLSFilter();
      typedef itk::QtSignalAdaptor SignalAdaptorType;
  	SignalAdaptorType signalAdaptor1;

	// Connect the adaptor as an observer of a Filter's event
	m_Filter->AddObserver( itk::IterationEvent(),
 signalAdaptor1.GetCommand() );

	// Connect the adaptor's Signal to the Qt Widget Slot
	QObject::connect( &signalAdaptor1, SIGNAL(Signal()), this,
SLOT(IterateUpate()) );

In the segmentation function
void Segment()
{
/*Set some parameters for filter*/
    ...
  try
    {
    filter->Update();
    }
  catch( itk::ExceptionObject & excep )
    {
    std::cerr << "Exception caught !" << std::endl;
    std::cerr << excep << std::endl;
    return;
    }
}

In SLOT IterateUpdate()
void IterateUpdate()
{
	std::cerr << "Iteration Number:"<<filter->GetElapsedIterations() <<
std::endl;
}

When I run it, the application will collapse at filter->Update(). When I
change filter->Update() to filter->Modified(), the application will no
collapse. But the filter runs iteratively only once, not as
filter->SetMaximumIterations( 100 ). And the SLOT IterateUpdate() can not be
called. Is there something wrong in signal setting? How can I watch
IterationEvent?


Thank you very much!


Chunyan