adds QtImageExample.py spmMotor.nii.gz #29

vtk/examples-pyside6-vtk/QtImageExample.py

@@ -0,0 +1,98 @@
+# coding=utf-8
+"""
+Example of displaying an image with VTK/Qt/Python.
+
+Original author: David Gobbi
+
+This example does not include proper image orientation or interaction.
+"""
+
+import sys
+import os
+
+from PySide6.QtCore import Qt
+from PySide6.QtWidgets import QApplication
+
+from vtk import vtkImageSlice, vtkImageSliceMapper, vtkImageProperty
+from vtk import vtkRenderer, vtkRenderWindow, vtkRenderWindowInteractor
+from vtk import vtkInteractorStyleImage
+from vtk import vtkNIFTIImageReader
+from vtk import vtkImageHistogramStatistics
+
+#from QVTKRenderWindowInteractor import QVTKRenderWindowInteractor
+from vtkmodules.qt.QVTKRenderWindowInteractor import QVTKRenderWindowInteractor
+
+def QVTKRenderWidgetImageExample(argv):
+    """A simple example that uses the QVTKRenderWindowInteractor class."""
+
+    if len(argv) < 2:
+        sys.stderr.write(
+            "This program needs a nifti file as its first argument\n")
+        sys.exit(1)
+
+    filename = argv[1]
+
+    # make sure image is readable before doing anything else
+    reader = vtkNIFTIImageReader()
+    reader.SetFileName(filename)
+    reader.Update()
+    image = reader.GetOutput()
+
+    # prefer the nifti "qform", use "sform" as a backup
+    matrix = reader.GetQFormMatrix()
+    if matrix is None:
+        matrix = reader.GetSFormMatrix()
+
+    # find a robust min, max range from the histogram
+    histinfo = vtkImageHistogramStatistics()
+    histinfo.SetInputData(image)
+    histinfo.Update()
+    minval, maxval = histinfo.GetAutoRange()
+    print("Image range: [%g, %g]" % (minval, maxval))
+
+    # every QT app needs an app object
+    app = QApplication(['QVTKRenderWindowInteractor'])
+
+    # create the widget
+    widget = QVTKRenderWindowInteractor()
+    widget.Initialize()
+    widget.Start()
+
+    # if you don't want the 'q' key to exit, comment this out
+    widget.AddObserver("ExitEvent", lambda o, e, a=app: a.quit())
+
+    # attach renderer to the display
+    renderer = vtkRenderer()
+    widget.GetRenderWindow().AddRenderer(renderer)
+
+    # the mapper
+    mapper = vtkImageSliceMapper()
+    mapper.SetInputData(image)
+    mapper.SliceAtFocalPointOn()
+
+    # the actor
+    actor = vtkImageSlice()
+    actor.SetMapper(mapper)
+    actor.GetProperty().SetColorWindow(maxval - minval)
+    actor.GetProperty().SetColorLevel(0.5*(minval + maxval))
+    renderer.AddActor(actor)
+
+    # set up the camera
+    camera = renderer.GetActiveCamera()
+    bounds = image.GetBounds()
+    xc = 0.5*(bounds[0] + bounds[1])
+    yc = 0.5*(bounds[2] + bounds[3])
+    zc = 0.5*(bounds[4] + bounds[5])
+    camera.SetFocalPoint(xc, yc, zc)
+    camera.SetPosition(xc, yc, bounds[5] + 1.0)
+    camera.SetViewUp(0.0, -1.0, 0.0)
+    camera.ParallelProjectionOn()
+    camera.SetParallelScale(0.5*(bounds[3]-bounds[2]))
+
+    # show the widget
+    widget.show()
+    # start event processing
+    app.exec()
+
+if __name__ == "__main__":
+    QVTKRenderWidgetImageExample(sys.argv)

vtk/examples-pyside6-vtk/README.md

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+# examples-pyside6-vtk
+
+## QtImageExample.py
+mamba activate bareVE
+wget https://github.com/neurolabusc/niivue-images/raw/main/spmMotor.nii.gz
+python QtImageExample.py spmMotor.nii.gz 
+
+