[vtkusers] vtkDistanceWidget and Dicom Images

[Leonardo M. Ramé]

Hi, I use this code to add a vtkDistanceWidget to a scene showing a
Dicom image:

distanceWidget = vtkDistanceWidget::New();
distanceWidget->SetInteractor(this->GetInteractor());
static_cast<vtkDistanceRepresentation*>(distanceWidget->GetRepresentation())->SetLabelFormat("%-#6.2f mm");
distanceWidget->On();

The problem here is the measures I'm getting from the distance widget
are not related to the real image. For example, when I measure one image
with another Dicom viewer, it shows that I has 360mm width, and the
vtkDistanceWidget says it has 1748,30mm.

How can I define the relation between the size of the real image and the
representation I'm showing on screen?

-- 
Leonardo M. Ramé
http://leonardorame.blogspot.com