- _marImageData->GetImageData()->GetExtent (_x1,_x2,_y1,_y2,_z1,_z2);
- _transformOrientation=vtkTransform::New();
- _transformOrientation->Identity();
+ vtkImageData* img = _marImageData->GetImageData();
+ if(img !=NULL){
+ img->GetExtent (_x1,_x2,_y1,_y2,_z1,_z2);
+ _transformOrientation=vtkTransform::New();
+ _transformOrientation->Identity();
+ }