TissueLens
Repository source: TissueLens
Description¶
This example uses two vtkClipDataSet filters to achieve a "tissue lens" effect. First, a vtkSphere implicit function is used to clip a spherical hole in the isosurface extracted with vtkFlyingEdges3D or vtkMarchingCubes. Then a geometric vtkSphereSource samples the original volume data using a vtkProbeFilter. vtkClipDataSet uses the resulting scalar point data to clip the sphere surface with the isosurface value.
Usage
TissueLens FullHead.mhd
Note
The skin color was selected from Table 7 in Improvement of Haar Feature Based Face Detection in OpenCV Incorporating Human Skin Color Characteristic
Info
The example uses src/Testing/Data/FullHead.mhd
which references src/Testing/Data/FullHead.raw.gz
.
Other languages
See (Cxx)
Question
If you have a question about this example, please use the VTK Discourse Forum
Code¶
TissueLens.py
#!/usr/bin/env python
# noinspection PyUnresolvedReferences
import vtkmodules.vtkInteractionStyle
# noinspection PyUnresolvedReferences
import vtkmodules.vtkRenderingOpenGL2
from vtkmodules.vtkCommonColor import vtkNamedColors
from vtkmodules.vtkCommonCore import (
VTK_VERSION_NUMBER,
vtkLookupTable,
vtkVersion
)
from vtkmodules.vtkCommonDataModel import vtkSphere
from vtkmodules.vtkFiltersCore import (
vtkFlyingEdges3D,
vtkMarchingCubes,
vtkProbeFilter
)
from vtkmodules.vtkFiltersGeneral import vtkClipDataSet
from vtkmodules.vtkFiltersSources import vtkSphereSource
from vtkmodules.vtkIOImage import vtkMetaImageReader
from vtkmodules.vtkRenderingCore import (
vtkActor,
vtkCamera,
vtkDataSetMapper,
vtkProperty,
vtkRenderWindow,
vtkRenderWindowInteractor,
vtkRenderer
)
def main():
# vtkFlyingEdges3D was introduced in VTK >= 8.2
use_flying_edges = vtk_version_ok(8, 2, 0)
colors = vtkNamedColors()
file_name = get_program_parameters()
colors.SetColor('SkinColor', [240, 184, 160, 255])
colors.SetColor('BackfaceColor', [255, 229, 200, 255])
colors.SetColor('BkgColor', [51, 77, 102, 255])
# Read the volume data
reader = vtkMetaImageReader()
reader.SetFileName(file_name)
reader.Update()
# An isosurface, or contour value of 500 is known to correspond to the
# skin of the patient.
if use_flying_edges:
try:
skin_extractor = vtkFlyingEdges3D()
except AttributeError:
skin_extractor = vtkMarchingCubes()
else:
skin_extractor = vtkMarchingCubes()
skin_extractor.SetInputConnection(reader.GetOutputPort())
skin_extractor.SetValue(0, 500)
# Define a spherical clip function to clip the isosurface
clip_function = vtkSphere()
clip_function.SetRadius(50)
clip_function.SetCenter(73, 52, 15)
# Clip the isosurface with a sphere
skin_clip = vtkClipDataSet()
skin_clip.SetInputConnection(skin_extractor.GetOutputPort())
skin_clip.SetClipFunction(clip_function)
skin_clip.SetValue(0)
skin_clip.GenerateClipScalarsOn()
skin_clip.Update()
skin_mapper = vtkDataSetMapper()
skin_mapper.SetInputConnection(skin_clip.GetOutputPort())
skin_mapper.ScalarVisibilityOff()
skin = vtkActor()
skin.SetMapper(skin_mapper)
skin.GetProperty().SetDiffuseColor(colors.GetColor3d('SkinColor'))
back_prop = vtkProperty()
back_prop.SetDiffuseColor(colors.GetColor3d('BackfaceColor'))
skin.SetBackfaceProperty(back_prop)
# Define a model for the "lens". Its geometry matches the implicit
# sphere used to clip the isosurface
lens_model = vtkSphereSource()
lens_model.SetRadius(50)
lens_model.SetCenter(73, 52, 15)
lens_model.SetPhiResolution(201)
lens_model.SetThetaResolution(101)
# Sample the input volume with the lens model geometry
lens_probe = vtkProbeFilter()
lens_probe.SetInputConnection(lens_model.GetOutputPort())
lens_probe.SetSourceConnection(reader.GetOutputPort())
# Clip the lens data with the isosurface value
lens_clip = vtkClipDataSet()
lens_clip.SetInputConnection(lens_probe.GetOutputPort())
lens_clip.SetValue(500)
lens_clip.GenerateClipScalarsOff()
lens_clip.Update()
# Define a suitable grayscale lut
bw_lut = vtkLookupTable()
bw_lut.SetTableRange(0, 2048)
bw_lut.SetSaturationRange(0, 0)
bw_lut.SetHueRange(0, 0)
bw_lut.SetValueRange(0.2, 1)
bw_lut.Build()
lens_mapper = vtkDataSetMapper()
lens_mapper.SetInputConnection(lens_clip.GetOutputPort())
lens_mapper.SetScalarRange(lens_clip.GetOutput().GetScalarRange())
lens_mapper.SetLookupTable(bw_lut)
lens = vtkActor()
lens.SetMapper(lens_mapper)
# It is convenient to create an initial view of the data. The FocalPoint
# and Position form a vector direction. Later on (ResetCamera() method)
# this vector is used to position the camera to look at the data in
# this direction.
a_camera = vtkCamera()
a_camera.SetViewUp(0, 0, -1)
a_camera.SetPosition(0, -1, 0)
a_camera.SetFocalPoint(0, 0, 0)
a_camera.ComputeViewPlaneNormal()
a_camera.Azimuth(30.0)
a_camera.Elevation(30.0)
# Create the renderer, the render window, and the interactor. The renderer
# draws into the render window, the interactor enables mouse- and
# keyboard-based interaction with the data within the render window.
#
a_renderer = vtkRenderer()
ren_win = vtkRenderWindow()
ren_win.AddRenderer(a_renderer)
iren = vtkRenderWindowInteractor()
iren.SetRenderWindow(ren_win)
# Actors are added to the renderer. An initial camera view is created.
# The Dolly() method moves the camera towards the FocalPoint,
# thereby enlarging the image.
a_renderer.AddActor(lens)
a_renderer.AddActor(skin)
a_renderer.SetActiveCamera(a_camera)
a_renderer.ResetCamera()
a_camera.Dolly(1.5)
# Set a background color for the renderer and set the size of the
# render window (expressed in pixels).
a_renderer.SetBackground(colors.GetColor3d('BkgColor'))
ren_win.SetSize(640, 480)
ren_win.SetWindowName('TissueLens')
# Note that when camera movement occurs (as it does in the Dolly()
# method), the clipping planes often need adjusting. Clipping planes
# consist of two planes: near and far along the view direction. The
# near plane clips out objects in front of the plane the far plane
# clips out objects behind the plane. This way only what is drawn
# between the planes is actually rendered.
a_renderer.ResetCameraClippingRange()
# Initialize the event loop and then start it.
ren_win.Render()
iren.Initialize()
iren.Start()
def get_program_parameters():
import argparse
description = 'The skin and bone is extracted from a CT dataset of the head and a "tissue lens" effect is applied.'
epilogue = '''
'''
parser = argparse.ArgumentParser(description=description, epilog=epilogue,
formatter_class=argparse.RawDescriptionHelpFormatter)
parser.add_argument('filename', help='FullHead.mhd.')
args = parser.parse_args()
return args.filename
def vtk_version_ok(major, minor, build):
"""
Check the VTK version.
:param major: Major version.
:param minor: Minor version.
:param build: Build version.
:return: True if the requested VTK version is greater or equal to the actual VTK version.
"""
needed_version = 10000000000 * int(major) + 100000000 * int(minor) + int(build)
try:
vtk_version_number = VTK_VERSION_NUMBER
except AttributeError: # as error:
ver = vtkVersion()
vtk_version_number = 10000000000 * ver.GetVTKMajorVersion() + 100000000 * ver.GetVTKMinorVersion() \
+ ver.GetVTKBuildVersion()
if vtk_version_number >= needed_version:
return True
else:
return False
if __name__ == '__main__':
main()