this->ConvertImageToImageDisplayExtent(input, w_ext, mOverlayReslice->GetOutput(), overExtent);
ClipDisplayedExtent(overExtent, mOverlayMapper->GetInput()->GetWholeExtent());
mOverlayActor->SetDisplayExtent( overExtent );
this->ConvertImageToImageDisplayExtent(input, w_ext, mOverlayReslice->GetOutput(), overExtent);
ClipDisplayedExtent(overExtent, mOverlayMapper->GetInput()->GetWholeExtent());
mOverlayActor->SetDisplayExtent( overExtent );