[vtkusers] problem access to specific voxel

[Hal Canary]

On 06/07/2013 01:08 PM, Hossein Nazem wrote:
> How can i access to specific voxel in VTK?
 >
> I have a volume from CT image.  From the dicom header I have "image
> position patient", "slice thikness" and "pixel spacing".  For example
> if "image position patient"=[-137.699; -310.699; -1222],  how can I
> reach this point in VTK? (for example change the color of this point)

Is something like this what you are looking for?

   vtkSmartPointer <vtkDICOMImageReader > * dicomImageReader =
     vtkSmartPointer <vtkDICOMImageReader >::New();
   dicomImageReader->SetDirectoryName( /*....*/ );
   dicomImageReader->Update();
   vtkImageData * imageData = dicomImageReader->GetOutput();
   double xyz[3] = {-137.699; -310.699; -1222};
   vtkIdType index = imageData->FindPoint(xyz[0], xyz[1], xyz[2]);
   if (index == -1) {
     //point outside of bounds
   } else {
     double value =
       imageData->GetPointData()->GetScalars()->GetComponent(index,0);
     // do something with value.
   }