[vmtk-users] VMTK Point co-ordinates system

[Ahmed H. <ahm...@gm...>]

Dear Luca

Thanks for your previous help. I have managed to use
vtkvmtkVesselnessMeasureImageFilter class and am displaying the
results successfully to Osirix output. Now I trying to use
vtkvmtkCollidingFrontsImageFilter. I am following the pythons scripts and
getting the expected results.
I can't determine ow to pass the two seed points to the
vtkvmtkCollidingFrontsImageFilter class using the SetSeeds1. I think I am
using the wrong co-ordinate system. I capture the ROI from Osirix which is
given to me in RAS system in mm. My understanding that VMTK uses IJK system
but it already has the origin and spacing values in the vtkImageData.
Should I convert my point coordinate manually using matrix transformation
or am I missing something? (Bellow is my code for
vtkvmtkCollidingFrontsImageFilter)

Thanks for your help.


    vtkIdList *my_VTKseedIdList1=vtkIdList::New();
    vtkIdList *my_VTKseedIdList2=vtkIdList::New();
//    vtkSmartPointer<vtkPoints> point11 =vtkSmartPointer<vtkPoints>::New();
    vtkPoints *point11 =vtkPoints::New();
    vtkPoints *points22=vtkPoints::New();
    vtkIdType pttyp1,pttyp2;


pttyp1=point11->InsertNextPoint(5,5,5);//(15.3,110.8,946.2);//{0,90,922};//{283,242,251};//
{18.5,-148.0,115};
    pttyp2=points22->InsertNextPoint(15,15,15);//(-10.8,95.8,931);//
{80,146,951};//{ 338,276, 218};//{44.0, -155.0, 110.5};
    my_VTKseedIdList1->InsertNextId(pttyp1);
    my_VTKseedIdList2->InsertNextId(pttyp2);

    vtkvmtkCollidingFrontsImageFilter *myVMTKcollidingFronts =
vtkvmtkCollidingFrontsImageFilter::New();
    myVMTKcollidingFronts->SetInput(myVTKspeedImage);     //myVTKspeedImage
is:   vtkImageData * myVTKspeedImage and I call it's update function and I
see the expected results when displaying it.
    myVMTKcollidingFronts->SetSeeds1(my_VTKseedIdList1);
    myVMTKcollidingFronts->SetSeeds2(my_VTKseedIdList2);
    myVMTKcollidingFronts->ApplyConnectivityOn();
    myVMTKcollidingFronts->StopOnTargetsOn();
    myVMTKcollidingFronts->Update();  // I get an empty image !


Ahmed A. Harouni