gistfile1.txt

      vtkSmartPointer<vtkImageHistogram> histogram = vtkSmartPointer<vtkImageHistogram>::New();
       histogram->SetInput(volumeChunk.getAttenuation());
       histogram->GenerateHistogramImageOn();
       histogram->SetHistogramImageScaleToLog();
       histogram->Update();
       

       histogram->PrintSelf (std::cout, vtkIndent());

        vtkSmartPointer<vtkJPEGWriter> writer =
        vtkSmartPointer<vtkJPEGWriter>::New();
        writer->SetFileName("attenuation_histogram.jpg");
        writer->SetInputConnection(histogram->GetOutputPort());
        writer->Write();