[Insight-users] Canny filter problems

[Renaud Winzenrieth]

Hi everybody,
I have some problems with the canny filter.
I do this:
vtkBMPreader->vtkImageLuminance->vtkImageCast->vtkImageExport
->itkImageImportType->itkCannyEdgeDetectionImageFilter->itkVTKImageExport
->itkImageExportType->vtkImageImport->vtkImageCast->vtkImageMapper
->vtkActor2D->vtkRenderer->......->Render()
My problem is that i obtaine a black window. If I skip the canny filter 
step everything is ok.
anybody can help me?