How to disable interpolation (bluring image) in ImagePlaneWidget?

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1

Hello, I’ve found that piece of code of running Multi Planar Reconstruction via ImagePlaneWidget and I wanted to run it, but it shows images blurred (can’t see raw pixels). I wanted to disable interpolation, but it seems not working, I mean I tried to use SetResliceInterpolateToNearestNeighbour function for vtkImagePlaneWidget class, but it seems had no effect. Any idea how to disable blurring?

from vtk import *

# Reslice cursor callback
def ResliceCursorCallback(obj,event):
    for i in range(0,3):
        ps = planeWidgetArray[i].GetPolyDataAlgorithm();
        origin = resliceCursorWidgetArray[i].GetResliceCursorRepresentation().GetPlaneSource().GetOrigin();
        ps.SetOrigin(origin);
        point1 = resliceCursorWidgetArray[i].GetResliceCursorRepresentation().GetPlaneSource().GetPoint1();
        ps.SetPoint1(point1);
        point2 = resliceCursorWidgetArray[i].GetResliceCursorRepresentation().GetPlaneSource().GetPoint2();
        ps.SetPoint2(point2);
        planeWidgetArray[i].UpdatePlacement();

# DICOM reader
reader = vtkDICOMImageReader();
reader.SetDirectoryName("CT");
reader.Update();
imageDims = reader.GetOutput().GetDimensions();

# // Bounding box
outline = vtkOutlineFilter();
outline.SetInputConnection(reader.GetOutputPort());

outlineMapper = vtkPolyDataMapper();
outlineMapper.SetInputConnection(outline.GetOutputPort());

outlineActor = vtkActor();
outlineActor.SetMapper(outlineMapper);
outlineActor.GetProperty().SetColor(1,1,0);

# // Mapper and actors for volume
volumeMapper = vtkPolyDataMapper();
volumeMapper.SetInputConnection(reader.GetOutputPort());

volumeActor = vtkActor();
volumeActor.SetMapper(volumeMapper);

# // Renderers
renWin = vtkRenderWindow();
RendererArray = [None]*4;
for i in range(0,4):
    RendererArray[i] = vtkRenderer();
    renWin.AddRenderer(RendererArray[i]);
renWin.SetMultiSamples(0);

# // Render window interactor
iren = vtkRenderWindowInteractor();
renWin.SetInteractor(iren);

# // Picker
picker = vtkCellPicker();
picker.SetTolerance(0.005);

# // Properties
ipwProp = vtkProperty();

# // 3D plane widgets
planeWidgetArray = [None]*3;
for i in range(0,3):
    planeWidgetArray[i] = vtkImagePlaneWidget();
    planeWidgetArray[i].SetInteractor(iren);
    planeWidgetArray[i].SetPicker(picker);
    planeWidgetArray[i].RestrictPlaneToVolumeOn();
    color = [0, 0, 0 ];
    color[i] = 1;
    planeWidgetArray[i].GetPlaneProperty().SetColor(color);
    planeWidgetArray[i].SetTexturePlaneProperty(ipwProp);
    planeWidgetArray[i].TextureInterpolateOff();
    planeWidgetArray[i].SetResliceInterpolateToLinear();
    planeWidgetArray[i].SetInputConnection(reader.GetOutputPort());
    planeWidgetArray[i].SetPlaneOrientation(i);
    planeWidgetArray[i].SetSliceIndex(int(imageDims[i] / 2));
    planeWidgetArray[i].DisplayTextOn();
    planeWidgetArray[i].SetDefaultRenderer(RendererArray[3]);
    planeWidgetArray[i].SetWindowLevel(1358, -27, 0);
    planeWidgetArray[i].On();
    planeWidgetArray[i].InteractionOff();

planeWidgetArray[1].SetLookupTable(planeWidgetArray[0].GetLookupTable()); 
planeWidgetArray[2].SetLookupTable(planeWidgetArray[0].GetLookupTable());

# // ResliceCursor
resliceCursor = vtkResliceCursor();
center = reader.GetOutput().GetCenter();
resliceCursor.SetCenter(center[0], center[1], center[2]);
resliceCursor.SetThickMode(0);
resliceCursor.SetThickness(10, 10, 10);
resliceCursor.SetHole(0);
resliceCursor.SetImage(reader.GetOutput());

# // 2D Reslice cursor widgets
resliceCursorRepArray = [None]*3;
resliceCursorWidgetArray = [None]*3;
viewUp = [[0, 0, -1],[0, 0, -1],[0, 1, 0]];
for i in range(0,3):
    resliceCursorWidgetArray[i] = vtkResliceCursorWidget();
    resliceCursorRepArray[i] = vtkResliceCursorLineRepresentation();
    resliceCursorWidgetArray[i].SetInteractor(iren);
    resliceCursorWidgetArray[i].SetRepresentation(resliceCursorRepArray[i]);
    resliceCursorRepArray[i].GetResliceCursorActor().GetCursorAlgorithm().SetResliceCursor(resliceCursor);
    resliceCursorRepArray[i].GetResliceCursorActor().GetCursorAlgorithm().SetReslicePlaneNormal(i);
    minVal = reader.GetOutput().GetScalarRange()[0];
    reslice = resliceCursorRepArray[i].GetReslice();
    reslice.SetInputConnection(reader.GetOutputPort());
    reslice.SetBackgroundColor(minVal, minVal, minVal, minVal);
    reslice.AutoCropOutputOn();
    reslice.Update();
    resliceCursorWidgetArray[i].SetDefaultRenderer(RendererArray[i]);
    resliceCursorWidgetArray[i].SetEnabled(1);
    RendererArray[i].GetActiveCamera().SetFocalPoint(0, 0, 0);
    camPos = [0, 0, 0];
    camPos[i] = 1;
    RendererArray[i].GetActiveCamera().SetPosition(camPos[0], camPos[1], camPos[2]);
    RendererArray[i].GetActiveCamera().ParallelProjectionOn();
    RendererArray[i].GetActiveCamera().SetViewUp(viewUp[i][0], viewUp[i][1], viewUp[i][2]);
    RendererArray[i].ResetCamera();
    resliceCursorWidgetArray[i].AddObserver('InteractionEvent',ResliceCursorCallback)
    range_color = reader.GetOutput().GetScalarRange();
    resliceCursorRepArray[i].SetWindowLevel(range_color[1] - range_color[0], (range_color[0] + range_color[1]) / 2.0, 0);
    planeWidgetArray[i].SetWindowLevel(range_color[1] - range_color[0], (range_color[0] + range_color[1]) / 2.0, 0);
    resliceCursorRepArray[i].SetLookupTable(resliceCursorRepArray[0].GetLookupTable());
    planeWidgetArray[i].GetColorMap().SetLookupTable(resliceCursorRepArray[0].GetLookupTable());
    
# // Background
RendererArray[0].SetBackground(0.3, 0.1, 0.1);
RendererArray[1].SetBackground(0.1, 0.3, 0.1);
RendererArray[2].SetBackground(0.1, 0.1, 0.3);
RendererArray[3].AddActor(volumeActor);
RendererArray[3].AddActor(outlineActor);
RendererArray[3].SetBackground(0.1, 0.1, 0.1);
renWin.SetSize(600, 600);

# // Render
RendererArray[0].SetViewport(0, 0, 0.5, 0.5);
RendererArray[1].SetViewport(0.5, 0, 1, 0.5);
RendererArray[2].SetViewport(0, 0.5, 0.5, 1);
RendererArray[3].SetViewport(0.5, 0.5, 1, 1);
renWin.Render();

# // Camera in 3D view
RendererArray[3].GetActiveCamera().Elevation(110);
RendererArray[3].GetActiveCamera().SetViewUp(0, 0, -1);
RendererArray[3].GetActiveCamera().Azimuth(45);
RendererArray[3].GetActiveCamera().Dolly(1.15);
RendererArray[3].ResetCameraClippingRange();

iren.Initialize()
iren.Start()
2

It has been a very long time since I’ve used vtkImagePlaneWidget, but my suggestion is to check the Reslice and Texture objects after the first render to make sure the widget set them correctly:

renWin.Render()
print(resliceCursorWidgetArray[0].GetReslice().GetInterpolationModeAsString())
print(resliceCursorWidgetArray[0].GetTexture().GetInterpolate())

Also I’ve had problems in the past where vtkTexture automatically resampled textures to a power of two (regardless of how Interpolate is set). What are the dimensions of your image?

3

512x512, I think.

Tried to use these prints, but vtkResliceCursorWidget class seems like doesn’t have any of these functions, while vtkResliceCursorLineRepresentation class had only get reslice and it showed NearestNeighbor

4

Ah, sorry. The title of this thread was “ImagePlaneWidget” so I thought you were using the vtkImagePlaneWidget. The vtkResliceCursorWidget is a different beast. I don’t have any advice for it because I’ve never used it.

For vtkImagePlaneWidget, at least, I know that it’s possible to turn off interpolation:

ipw
ipw600×600 21.8 KB