[vtkusers] How to display dicom images without scaling?

[Jothy]

Don't you think

viewer->GetInteractorStyle ()->AutoAdjustCameraClippingRangeOff ();

this should be On().

Jothy

On Sun, Jul 24, 2011 at 8:50 PM, Joseph D. Wieber Jr. <jdwieber at gmail.com>wrote:

> **
>
> Hello,
>
> I'm new to VTK and I'm working on a project that reads dicom image files.
> The files I have are 512x512 pixels, but when I view them they display at
> approx 150x150 pixels.  I'm using Qt to create the UI via Qt designer with
> the qvtkWidget.  I'm using the vtkImageViewer2 class to handle the
> visualization.  I pasted my initialization code below.  The algorithm I'm
> working on is intelligent scissors (user guided segmentation).  I originally
> implemented it in OpenCV, but need to convert my app. to use VTK.  I need to
> extract pixel locations from left click and mouse over events, and I have
> this part working correctly.  However, for the algorithm to work properly I
> need to do a lookup into a cost table based on pixel location.  The cost
> table is built to the correct size (512x512), and when I write out the
> dimensions of the image I see 512x512, but when I do the picking I get
> locations in the range of 0 - 150.  Indeed, the displayed image takes up
> only a small portion of the widget (see image below).  I tried searching the
> web and the mailing list, but found nothing.  I'm not sure what search terms
> are appropriate.  I found in the vtkImageViewer2 documentation that dicom
> images are scaled by Z coordinate of the image slice.  When I print out the
> position of the image the z coord is 0, but I don't know what (or how to
> get) the position of the camera is.  How can I make the visualization
> pipeline display the image at full size?
>
> Thank you in advance for any help or suggestions.
>
> Regards,
>
> Joseph.
>
> MainWindow::MainWindow( QWidget *parent, const string& fname ) :
>     QMainWindow( parent ),
>     ui( new Ui::MainWindow ),
>     m_fileName( fname )
> {
>     ui->setupUi( this );
>
>     // Read the image
>     vtkSmartPointer< vtkDICOMImageReader > reader =
>             vtkSmartPointer< vtkDICOMImageReader >::New();
>     reader->SetFileName( m_fileName.c_str () );
>     reader->Update ();
>
>     // setup the intelligent scissors object
>     //mexican hat LoG
>     double laplacian[] = {  0.,  0., -1.,  0.,  0.,
>                             0., -1., -2., -1.,  0.,
>                            -1., -2., 16., -2., -1.,
>                             0., -1., -2., -1.,  0.,
>                             0.,  0., -1.,  0.,  0. };
>
>     m_spScissors.reset( new IntelligentScissors( reader->GetOutput (),
>                                                  laplacian ) );
>
>     // Setup the blending function to overlay the segmentation contour on
> the image
>     vtkSmartPointer< vtkImageBlend > blend =
>             vtkSmartPointer< vtkImageBlend >::New();
>     blend->AddInputConnection( reader->GetOutputPort() );
>     blend->SetOpacity( 0, 0.6 );
>     blend->AddInputConnection( m_spScissors->getPathImage () );
>     blend->SetOpacity( 1, 0.4 );
>
>     vtkSmartPointer< vtkImageViewer2 > viewer =
>             vtkSmartPointer< vtkImageViewer2 >::New();
>     viewer->SetInputConnection ( blend->GetOutputPort () );
>
>     // make the viewer use the interactor supplied from the qvtk widget
>     viewer->SetupInteractor ( ui->qvtkWidget->GetInteractor () );
>
>     //bind Qt and VTK
>     ui->qvtkWidget->SetRenderWindow ( viewer->GetRenderWindow () );
>
>     //try to get image displayed at full size
>     viewer->GetInteractorStyle ()->AutoAdjustCameraClippingRangeOff ();
>
>     // Annotate the image with mouse over pixel information
>     vtkSmartPointer< vtkCornerAnnotation > cornerAnnotation =
>             vtkSmartPointer< vtkCornerAnnotation >::New();
>     cornerAnnotation->SetLinearFontScaleFactor( 2 );
>     cornerAnnotation->SetNonlinearFontScaleFactor( 1 );
>     cornerAnnotation->SetMaximumFontSize( 15 );
>     cornerAnnotation->SetText( 0, "Off Image" );
>     cornerAnnotation->SetText( 3, "<window>\n<level>" );
>     cornerAnnotation->GetTextProperty()->SetColor( 1, 0, 0 );
>     viewer->GetRenderer ()->AddViewProp ( cornerAnnotation );
>
>     // Picker to pick pixels
>     vtkSmartPointer< vtkPropPicker > propPicker =
>             vtkSmartPointer< vtkPropPicker >::New();
>     propPicker->PickFromListOn();
>
>     // Give the picker a prop to pick
>     vtkImageActor* imageActor = viewer->GetImageActor();
>     propPicker->AddPickList( imageActor );
>
>     // disable interpolation, so we can see each pixel
>     imageActor->InterpolateOff();
>
>     // Set callback functions
>     vtkInteractorStyleImage* imageStyle = viewer->GetInteractorStyle();
>
>     //listen to MouseMoveEvents invoked by the interactor's style
>     OnMouseMovePtr onMouseMove = OnMouseMovePtr::New();
>     onMouseMove->SetViewer( viewer );
>     onMouseMove->SetAnnotation( cornerAnnotation );
>     onMouseMove->SetPicker( propPicker );
>     onMouseMove->SetIntelligentScissors ( m_spScissors );
>     imageStyle->AddObserver( vtkCommand::MouseMoveEvent, onMouseMove );
>
>     //listen to LeftButtonPressEvent invoked by the interactor's style
>     OnLeftClickPtr onLeftClick = OnLeftClickPtr::New ();
>     onLeftClick->SetViewer ( viewer );
>     onLeftClick->SetAnnotation ( cornerAnnotation );
>     onLeftClick->SetPicker ( propPicker );
>     onLeftClick->SetIntelligentScissors ( m_spScissors );
>     imageStyle->AddObserver ( vtkCommand::LeftButtonPressEvent, onLeftClick
> );
>
>     viewer->Render ();
> }
>
>
> [image: View in HTML to see image]
>
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