Documentation/4.6/ScriptRepository

2017-02-22T15:40:58Z

Kmader: to make the code a bit more runnable since the imports are required

<noinclude>{{documentation/versioncheck}}</noinclude>
__TOC__

=Community-contributed modules=

Usage: save the .py file to a directory, add the directory to the additional module paths in the Slicer application settings (choose in the menu: Edit / Application settings, click Modules, click >> next to Additional module paths, click Add, and choose the .py file's location).

==Filters==
* [https://raw.github.com/pieper/VolumeMasker/master/VolumeMasker.py VolumeMasker.py]: Update a target volume with the results of setting all input volume voxels to 0 except for those that correspond to a selected label value in an input label map (Used for example in the volume rendering in [https://www.youtube.com/watch?v=dfu2gugHLHs this video).

==DICOM==
* [https://gist.github.com/pieper/6186477 dicom header browser] to easily scroll through dicom files using dcmdump.
* [https://subversion.assembla.com/svn/slicerrt/trunk/SlicerRt/src/BatchProcessing SlicerRT batch processing] to batch convert RT structure sets to labelmap NRRD files.

==Informatics==
* [https://subversion.assembla.com/svn/slicerrt/trunk/SlicerRt/sandbox/MarkupsInfoModule/MarkupsInfo.py MarkupsInfo.py]: Compute the total length between all the points of a markup list.
* [https://subversion.assembla.com/svn/slicerrt/trunk/SlicerRt/sandbox/LineProfile/LineProfile.py LineProfile.py]: Compute intensity profile in a volume along a line.

=Community-contributed examples=

Usage: Copy-paste the shown code lines or linked .py file contents into Python console in Slicer.

==Capture==
* Get a MRML node in the scene based on the node name and call methods of that object. For the MRHead sample data:
vol=slicer.util.getNode('MR*')
vol.GetImageData().GetDimensions()
* Capture the full Slicer screen and save it into a file
img = qt.QPixmap.grabWidget(slicer.util.mainWindow()).toImage()
img.save('c:/tmp/test.png')
* [https://subversion.assembla.com/svn/slicerrt/trunk/SlicerRt/sandbox/CaptureRotationVideo/CaptureRotationVideo.py CaptureRotationVideo.py]: Capture a video of the scene rotating in the 3D view

==Launching Slicer==
* How to open an .mrb file with Slicer at the command line?
Slicer.exe --python-code "slicer.util.loadScene( 'f:/2013-08-23-Scene.mrb' )"
* How to run a script in the Slicer environment in batch mode (without showing any graphical user interface)?
Slicer.exe --python-code "doSomething; doSomethingElse; etc." --testing --no-splash --no-main-window

==DICOM==
* How to access tags of DICOM images imported into Slicer? For example, to print the first patient's first study's first series' "0020,0032" field:
db=slicer.dicomDatabase
patientList=db.patients()
studyList=db.studiesForPatient(patientList[0])
seriesList=db.seriesForStudy(studyList[0])
fileList=db.filesForSeries(seriesList[0])
print db.fileValue(fileList[0],'0020,0032')

* How to access tag of a volume loaded from DICOM? For example, get the patient position stored in a volume:
volumeName='2: ENT IMRT'
n=slicer.util.getNode(volumeName)
instUids=n.GetAttribute('DICOM.instanceUIDs').split()
filename=slicer.dicomDatabase.fileForInstance(instUids[0])
print slicer.dicomDatabase.fileValue(filename,'0018,5100')

* How to access tag of an item in the Subject Hierachy tree? For example, get the content time tag of a structure set:
rtStructName = '3: RTSTRUCT: PROS'
rtStructNode = slicer.util.getNode(rtStructName)
rtStructSubjectHierarchyNode = slicer.vtkMRMLSubjectHierarchyNode.GetAssociatedSubjectHierarchyNode(rtStructNode)
ctSliceInstanceUids = rtStructSubjectHierarchyNode.GetAttribute('DICOM.ReferencedInstanceUIDs').split()
filename = slicer.dicomDatabase.fileForInstance(ctSliceInstanceUids[0])
print slicer.dicomDatabase.fileValue(filename,'0008,0033')

==Toolbar functions==
* How to turn on slice intersections in the crosshair menu on the toolbar:
viewNodes = slicer.mrmlScene.GetNodesByClass('vtkMRMLSliceCompositeNode')
viewNodes.UnRegister(slicer.mrmlScene)
viewNodes.InitTraversal()
viewNode = viewNodes.GetNextItemAsObject()
while viewNode:
viewNode.SetSliceIntersectionVisibility(1)
viewNode = viewNodes.GetNextItemAsObject()

How to find similar functions? For this one I searched for "slice intersections" text in the whole slicer source code, found that the function is implemented in Base\QTGUI\qSlicerViewersToolBar.cxx, then translated the qSlicerViewersToolBarPrivate::setSliceIntersectionVisible(bool visible) method to Python.

==Manipulating objects in the slice viewer==
* How to define/edit a circular region of interest in a slice viewer?

Drop two markup points on a slice view and copy-paste the code below into the Python console. After this, as you move the markups you’ll see a circle following the markups.

# Update the sphere from the fiducial points
def UpdateSphere(param1, param2):
centerPointCoord = [0.0, 0.0, 0.0]
markups.GetNthFiducialPosition(0,centerPointCoord)
circumferencePointCoord = [0.0, 0.0, 0.0]
markups.GetNthFiducialPosition(1,circumferencePointCoord)
sphere.SetCenter(centerPointCoord)
radius=math.sqrt((centerPointCoord[0]-circumferencePointCoord[0])**2+(centerPointCoord[1]-circumferencePointCoord[1])**2+(centerPointCoord[2]-circumferencePointCoord[2])**2)
sphere.SetRadius(radius)
sphere.SetPhiResolution(30)
sphere.SetThetaResolution(30)
sphere.Update()

# Get a reference to the markup
markups=slicer.util.getNode('F')
# Create the sphere that will intersect the slice viewer
sphere = vtk.vtkSphereSource()
# Initial positioning of the sphere
UpdateSphere(0,0)
# Create model node and add to scene
model = slicer.vtkMRMLModelNode()
model.SetAndObservePolyData(sphere.GetOutput())
modelDisplay = slicer.vtkMRMLModelDisplayNode()
modelDisplay.SetSliceIntersectionVisibility(True) # Show in slice view
modelDisplay.SetVisibility(False) # Hide in 3D view
slicer.mrmlScene.AddNode(modelDisplay)
model.SetAndObserveDisplayNodeID(modelDisplay.GetID())
modelDisplay.SetInputPolyData(model.GetPolyData())
slicer.mrmlScene.AddNode(model)
# Call UpdateSphere whenever the fiducials are changed
markups.AddObserver("ModifiedEvent", UpdateSphere, 2)

== Add a texture mapped plane to the scene as a model ==
Note that model textures are not exposed in the GUI and are not saved in the scene
<pre>
# use dummy image data here
e = vtk.vtkImageEllipsoidSource()

scene = slicer.mrmlScene

# Create model node
model = slicer.vtkMRMLModelNode()
model.SetScene(scene)
model.SetName(scene.GenerateUniqueName("2DImageModel"))

planeSource = vtk.vtkPlaneSource()
model.SetAndObservePolyData(planeSource.GetOutput())

# Create display node
modelDisplay = slicer.vtkMRMLModelDisplayNode()
modelDisplay.SetColor(1,1,0) # yellow
modelDisplay.SetBackfaceCulling(0)
modelDisplay.SetScene(scene)
scene.AddNode(modelDisplay)
model.SetAndObserveDisplayNodeID(modelDisplay.GetID())

# Add to scene
modelDisplay.SetAndObserveTextureImageData(e.GetOutput())
scene.AddNode(model)

transform = slicer.vtkMRMLLinearTransformNode()
scene.AddNode(transform)
model.SetAndObserveTransformNodeID(transform.GetID())

vTransform = vtk.vtkTransform()
vTransform.Scale(50,50,50)
vTransform.RotateX(30)
transform.SetAndObserveMatrixTransformToParent(vTransform.GetMatrix())
</pre>

== Export a model to Blender, including color ==

<pre>
plyFilePath = "/tmp/fibers.ply"

lineDisplayNode = getNode("*LineDisplay*")

tuber = vtk.vtkTubeFilter()
tuber.SetInput(lineDisplayNode.GetOutputPolyData())

tubes = tuber.GetOutput()
tubes.Update()
scalars = tubes.GetPointData().GetArray(0)
scalars.SetName("scalars")

triangles = vtk.vtkTriangleFilter()
triangles.SetInput(tubes)

colorNode = lineDisplayNode.GetColorNode()
lookupTable = vtk.vtkLookupTable()
lookupTable.DeepCopy(colorNode.GetLookupTable())
lookupTable.SetTableRange(0,1)

plyWriter = vtk.vtkPLYWriter()
plyWriter.SetInput(triangles.GetOutput())
plyWriter.SetLookupTable(lookupTable)
plyWriter.SetArrayName("scalars")

plyWriter.SetFileName(plyFilePath)
plyWriter.Write()
</pre>

== Clone a volume ==
This example shows how to clone the MRHead sample volume, including its pixel data and display settings.
<pre>
sourceVolumeNode = slicer.util.getNode('MRHead')
volumesLogic = slicer.modules.volumes.logic()
clonedVolumeNode = volumesLogic.CloneVolume(slicer.mrmlScene, sourceVolumeNode, 'Cloned volume')
</pre>

== Create a new volume ==
This example shows how to create a new empty volume.
<pre>
imageSize=[512, 512, 512]
imageSpacing=[1.0, 1.0, 1.0]
voxelType=vtk.VTK_UNSIGNED_CHAR
# Create an empty image volume
imageData=vtk.vtkImageData()
imageData.SetDimensions(imageSize)
imageData.AllocateScalars(voxelType, 1)
thresholder=vtk.vtkImageThreshold()
thresholder.SetInputData(imageData)
thresholder.SetInValue(0)
thresholder.SetOutValue(0)
# Create volume node
volumeNode=slicer.vtkMRMLScalarVolumeNode()
volumeNode.SetSpacing(imageSpacing)
volumeNode.SetImageDataConnection(thresholder.GetOutputPort())
# Add volume to scene
slicer.mrmlScene.AddNode(volumeNode)
displayNode=slicer.vtkMRMLScalarVolumeDisplayNode()
slicer.mrmlScene.AddNode(displayNode)
colorNode = slicer.util.getNode('Grey')
displayNode.SetAndObserveColorNodeID(colorNode.GetID())
volumeNode.SetAndObserveDisplayNodeID(displayNode.GetID())
volumeNode.CreateDefaultStorageNode()
</pre>

== Modify voxels in a volume ==
This example shows how to change voxels values of the MRHead sample volume.
The values will be computed by function f(r,a,s,) = (r-10)*(r-10)+(a+15)*(a+15)+s*s.
<pre>
volumeNode=slicer.util.getNode('MRHead')
ijkToRas = vtk.vtkMatrix4x4()
volumeNode.GetIJKToRASMatrix(ijkToRas)
imageData=volumeNode.GetImageData()
extent = imageData.GetExtent()
for k in xrange(extent[4], extent[5]+1):
for j in xrange(extent[2], extent[3]+1):
for i in xrange(extent[0], extent[1]+1):
position_Ijk=[i, j, k, 1]
position_Ras=ijkToRas.MultiplyPoint(position_Ijk)
r=position_Ras[0]
a=position_Ras[1]
s=position_Ras[2]
functionValue=(r-10)*(r-10)+(a+15)*(a+15)+s*s
imageData.SetScalarComponentFromDouble(i,j,k,0,functionValue)
imageData.SetScalarComponentFromFloat(distortionVectorPosition_Ijk[0], distortionVectorPosition_Ijk[1], distortionVectorPosition_Ijk[2], 0, fillValue)
imageData.Modified()
</pre>

== Access values in a DTI tensor volume ==
This example shows how to access individual tensors at the voxel level.

First load your DWI volume and estimate tensors to produce a DTI volume called ‘Output DTI Volume’

Then open the python window: View->Python interactor

Use this command to access tensors through numpy:

<pre>
tensors = array('Output DTI Volume')
</pre>

Type the following code into the Python window to access all tensor components using vtk commands:

<pre>
volumeNode=slicer.util.getNode('Output DTI Volume')
imageData=volumeNode.GetImageData()
tensors = imageData.GetPointData().GetTensors()
extent = imageData.GetExtent()
idx = 0
for k in xrange(extent[4], extent[5]+1):
for j in xrange(extent[2], extent[3]+1):
for i in xrange(extent[0], extent[1]+1):
tensors.GetTuple9(idx)
idx += 1
</pre>

== Change window/level (brightness/contrast) or colormap of a volume ==
This example shows how to change window/level of the MRHead sample volume.
<pre>
volumeNode = getNode('MRHead')
displayNode = volumeNode.GetDisplayNode()
displayNode.AutoWindowLevelOff()
displayNode.SetWindow(50)
displayNode.SetLevel(100)
</pre>

Change color mapping from grayscale to rainbow:
<pre>
displayNode.SetAndObserveColorNodeID('vtkMRMLColorTableNodeRainbow')
</pre>

== Manipulate a Slice View ==

<pre>
lm = slicer.app.layoutManager()
red = lm.sliceWidget('Red')
redLogic = red.sliceLogic()
# Print current slice offset position
print redLogic.GetSliceOffset()
# Change slice position
redLogic.SetSliceOffset(20)
</pre>

== Save a series of images from a Slice View ==

Save the following into a file such as '/tmp/record.py' and then in the slicer python console type "execfile('/tmp/record.py')"

<pre>
layoutName = 'Green'
imagePathPattern = '/tmp/image-%03d.png'
steps = 10

widget = slicer.app.layoutManager().sliceWidget(layoutName)
view = widget.sliceView()
logic = widget.sliceLogic()
bounds = [0,]*6
logic.GetSliceBounds(bounds)

for step in range(steps):
offset = bounds[4] + step/(1.*steps) * (bounds[5]-bounds[4])
logic.SetSliceOffset(offset)
view.forceRender()
image = qt.QPixmap.grabWidget(view).toImage()
image.save(imagePathPattern % step)
</pre>

== Show a volume in the Slice Views ==

<pre>
volumeNode = slicer.util.getNode('YourVolumeNode')
applicationLogic = slicer.app.applicationLogic()
selectionNode = applicationLogic.GetSelectionNode()
selectionNode.SetSecondaryVolumeID(volumeNode.GetID())
applicationLogic.PropagateForegroundVolumeSelection(0)
</pre>

or

<pre>
n = slicer.util.getNode('YourVolumeNode')
for color in ['Red', 'Yellow', 'Green']:
slicer.app.layoutManager().sliceWidget(color).sliceLogic().GetSliceCompositeNode().SetForegroundVolumeID(n.GetID())
</pre>

== Change opacity of foreground volume in the Slice Views ==

<pre>
lm = slicer.app.layoutManager()
sliceLogic = lm.sliceWidget('Red').sliceLogic()
compositeNode = sliceLogic.GetSliceCompositeNode()
compositeNode.SetForegroundOpacity(0.4)
</pre>

== Center the 3D View on the Scene ==
<pre>
layoutManager = slicer.app.layoutManager()
threeDWidget = layoutManager.threeDWidget(0)
threeDView = threeDWidget.threeDView()
threeDView.resetFocalPoint()
</pre>

== Display text in a 3D view or slice view ==

The easiest way to show information overlaid on a viewer is to use corner annotations.

<pre>
view=slicer.app.layoutManager().threeDWidget(0).threeDView()
# Set text to "Something"
view.cornerAnnotation().SetText(vtk.vtkCornerAnnotation.UpperRight,"Something")
# Set color to red
view.cornerAnnotation().GetTextProperty().SetColor(1,0,0)
# Update the view
view.forceRender()
</pre>

== Turning off interpolation ==

You can turn off interpolation for newly loaded volumes with this script from Steve Pieper.

<pre>
def NoInterpolate(caller,event):
for node in slicer.util.getNodes('*').values():
if node.IsA('vtkMRMLScalarVolumeDisplayNode'):
node.SetInterpolate(0)

slicer.mrmlScene.AddObserver(slicer.mrmlScene.NodeAddedEvent, NoInterpolate)
</pre>

The below link explains how to put this in your startup script.

http://www.na-mic.org/Wiki/index.php/AHM2012-Slicer-Python#Refining_the_code_and_UI_with_slicerrc

== Customize viewer layout ==

Show a custom layout of a 3D view on top of the red slice view:

<pre>
customLayout = ("<layout type=\"vertical\" split=\"true\" >"
" <item>"
" <view class=\"vtkMRMLViewNode\" singletontag=\"1\">"
" <property name=\"viewlabel\" action=\"default\">1</property>"
" </view>"
" </item>"
" <item>"
" <view class=\"vtkMRMLSliceNode\" singletontag=\"Red\">"
" <property name=\"orientation\" action=\"default\">Axial</property>"
" <property name=\"viewlabel\" action=\"default\">R</property>"
" <property name=\"viewcolor\" action=\"default\">#F34A33</property>"
" </view>"
" </item>"
"</layout>")

customLayoutId=501

layoutManager = slicer.app.layoutManager()
layoutManager.layoutLogic().GetLayoutNode().AddLayoutDescription(customLayoutId, customLayout)
layoutManager.setLayout(customLayoutId)
</pre>

See description of standard layouts (that can be used as examples) here:
https://github.com/Slicer/Slicer/blob/master/Libs/MRML/Logic/vtkMRMLLayoutLogic.cxx

== Running an ITK filter in Python using SimpleITK ==
Open the "Sample Data" module and download "MR Head", then paste the following snippet in Python interactor:
<pre>
import SimpleITK as sitk
import sitkUtils
inputImage = sitkUtils.PullFromSlicer('MRHead')
filter = sitk.SignedMaurerDistanceMapImageFilter()
outputImage = filter.Execute(inputImage)
sitkUtils.PushToSlicer(outputImage,'outputImage')
</pre>

More information:
* See the SimpleITK documentation for SimpleITK examples: http://www.itk.org/SimpleITKDoxygen/html/examples.html
* sitkUtils in Slicer is used for pushing and pulling images from Slicer to SimpleITK: https://github.com/Slicer/Slicer/blob/master/Base/Python/sitkUtils.py

== Get current mouse coordinates in a slice view ==

You can get 3D (RAS) coordinates of the current mouse cursor from the crosshair singleton node as shown in the example below:

<pre>
def onMouseMoved(observer,eventid):
ras=[0,0,0]
crosshairNode.GetCursorPositionRAS(ras)
print(ras)

crosshairNode=slicer.util.getNode('Crosshair')
crosshairNode.AddObserver(slicer.vtkMRMLCrosshairNode.CursorPositionModifiedEvent, onMouseMoved)
</pre>

== Thick slab reconstruction and maximum/minimum intensity volume projections ==

Set up 'red' slice viewer to show thick slab reconstructed from 3 slices:
<pre>
sliceNode = slicer.mrmlScene.GetNodeByID('vtkMRMLSliceNodeRed')
appLogic = slicer.app.applicationLogic()
sliceLogic = appLogic.GetSliceLogic(sliceNode)
sliceLayerLogic = sliceLogic.GetBackgroundLayer()
reslice = sliceLayerLogic.GetReslice()
reslice.SetSlabModeToMean()
reslice.SetSlabNumberOfSlices(10) # mean of 10 slices will computed
reslice.SetSlabSliceSpacingFraction(0.3) # spacing between each slice is 0.3 pixel (total 10 * 0.3 = 3 pixel neighborhood)
sliceNode.Modified()
</pre>

Set up 'red' slice viewer to show maximum intensity projection (MIP):
<pre>
sliceNode = slicer.mrmlScene.GetNodeByID('vtkMRMLSliceNodeRed')
appLogic = slicer.app.applicationLogic()
sliceLogic = appLogic.GetSliceLogic(sliceNode)
sliceLayerLogic = sliceLogic.GetBackgroundLayer()
reslice = sliceLayerLogic.GetReslice()
reslice.SetSlabModeToMax()
reslice.SetSlabNumberOfSlices(600) # use a large number of slices (600) to cover the entire volume
reslice.SetSlabSliceSpacingFraction(0.5) # spacing between slices are 0.5 pixel (supersampling is useful to reduce interpolation artifacts)
sliceNode.Modified()
</pre>

The projected image is available in a ''vtkImageData'' object by calling ''reslice.GetOutput()''.

== Change default file type for nodes (that have never been saved yet) ==
Default node can be specified that will be used as a basis of all new storage nodes. This can be used for setting default file extension. For example, change file format to STL for model nodes:
<pre>
msn=slicer.vtkMRMLModelStorageNode()
msn.SetDefaultWriteFileExtension('stl')
slicer.mrmlScene.AddDefaultNode(msn)
</pre>

== Change file type for saving for all volumes (with already existing storage nodes) ==
<pre>
requiredFileExtension = '.nia'
originalFileExtension = '.nrrd'
volumeNodes = slicer.mrmlScene.GetNodesByClass('vtkMRMLScalarVolumeNode')
volumeNodes.UnRegister(slicer.mrmlScene)
volumeNodes.InitTraversal()
volumeNode = volumeNodes.GetNextItemAsObject()
while volumeNode:
volumeStorageNode = volumeNode.GetStorageNode()
if not volumeStorageNode:
volumeStorageNode = volumeNode.CreateDefaultStorageNode()
slicer.mrmlScene.AddNode(volumeStorageNode)
volumeStorageNode.UnRegister(None)
volumeNode.SetAndObserveStorageNodeID(volumeStorageNode.GetID())
volumeStorageNode.SetFileName(volumeNode.GetName()+requiredFileExtension)
else:
volumeStorageNode.SetFileName(volumeStorageNode.GetFileName().replace(originalFileExtension,requiredFileExtension))
volumeNode = volumeNodes.GetNextItemAsObject()
</pre>

== Segmentations ==

For all operations accessing or manupilating the internals of a segmentation will need this import!
<pre>
import vtkSegmentationCorePython as vtkSegmentationCore
</pre>

=== Get a segment ===
<pre>
segmentation = segmentationNode.GetSegmentation()
segment = segmentation.GetSegment(segmentID)
</pre>

=== Get a representation of a segment ===
<pre>
# Get representation from a single segment. If it does not exist, it will return None
segment.GetRepresentation(vtkSegmentationCore.vtkSegmentationConverter.GetSegmentationBinaryLabelmapRepresentationName()) # This gets the binary labelmap, but same idea for all others

# Get representation for a single segment. Convert temporarily for that particular segment if needed. Applies parent transforms by default (if not desired, another argument needs to be added to the end: false)
slicer.vtkSlicerSegmentationsModuleLogic.GetSegmentBinaryLabelmapRepresentation(segmentationNode, segmentID, outputOrientedImageData) # Get labelmap
slicer.vtkSlicerSegmentationsModuleLogic.GetSegmentRepresentation(segmentationNode, segmentID, vtkSegmentationCore.vtkSegmentationConverter.GetSegmentationClosedSurfaceRepresentationName(), outputPolyData) # Any representation
</pre>

=== Convert using default path and conversion parameters ===
<pre>
segmentation.CreateRepresentation(vtkSegmentationCore.vtkSegmentationConverter.GetSegmentationBinaryLabelmapRepresentationName()) # This creates binary labelmap, but same idea for all others
</pre>

=== Convert using custom path or conversion parameters ===
<pre>
# Custom path
TODO

# Custom conversion parameter
referenceGeometry=vtkSegmentationCore.vtkSegmentationConverter.SerializeImageGeometry(referenceImageData)
segmentation.SetConversionParameter(vtkSegmentationCore.vtkSegmentationConverter.GetReferenceImageGeometryParameterName(), referenceGeometry)
</pre>

Slicer Wiki - User contributions [en]

Documentation/4.6/ScriptRepository