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#!/usr/bin/env python
import os
import vtk
from vtk.test import Testing
from vtk.util.misc import vtkGetDataRoot
VTK_DATA_ROOT = vtkGetDataRoot()
# The current directory must be writeable.
#
try:
filename = "mni-thinplatespline.xfm"
channel = open(filename, "wb")
channel.close()
# first, create an image to warp
imageGrid = vtk.vtkImageGridSource()
imageGrid.SetGridSpacing(16, 16, 0)
imageGrid.SetGridOrigin(0, 0, 0)
imageGrid.SetDataExtent(0, 255, 0, 255, 0, 0)
imageGrid.SetDataScalarTypeToUnsignedChar()
table = vtk.vtkLookupTable()
table.SetTableRange(0, 1)
table.SetValueRange(1.0, 0.0)
table.SetSaturationRange(0.0, 0.0)
table.SetHueRange(0.0, 0.0)
table.SetAlphaRange(0.0, 1.0)
table.Build()
alpha = vtk.vtkImageMapToColors()
alpha.SetInputConnection(imageGrid.GetOutputPort())
alpha.SetLookupTable(table)
reader1 = vtk.vtkBMPReader()
reader1.SetFileName(VTK_DATA_ROOT + "/Data/masonry.bmp")
blend = vtk.vtkImageBlend()
blend.AddInputConnection(reader1.GetOutputPort())
blend.AddInputConnection(alpha.GetOutputPort())
# next, create a ThinPlateSpline transform
p1 = vtk.vtkPoints()
p1.SetNumberOfPoints(8)
p1.SetPoint(0, 0, 0, 0)
p1.SetPoint(1, 0, 255, 0)
p1.SetPoint(2, 255, 0, 0)
p1.SetPoint(3, 255, 255, 0)
p1.SetPoint(4, 96, 96, 0)
p1.SetPoint(5, 96, 159, 0)
p1.SetPoint(6, 159, 159, 0)
p1.SetPoint(7, 159, 96, 0)
p2 = vtk.vtkPoints()
p2.SetNumberOfPoints(8)
p2.SetPoint(0, 0, 0, 0)
p2.SetPoint(1, 0, 255, 0)
p2.SetPoint(2, 255, 0, 0)
p2.SetPoint(3, 255, 255, 0)
p2.SetPoint(4, 96, 159, 0)
p2.SetPoint(5, 159, 159, 0)
p2.SetPoint(6, 159, 96, 0)
p2.SetPoint(7, 96, 96, 0)
thinPlate0 = vtk.vtkThinPlateSplineTransform()
thinPlate0.SetSourceLandmarks(p1)
thinPlate0.SetTargetLandmarks(p2)
thinPlate0.SetBasisToR2LogR()
# write the tps to a file
tpsWriter = vtk.vtkMNITransformWriter()
tpsWriter.SetFileName(filename)
tpsWriter.SetTransform(thinPlate0)
tpsWriter.Write()
# read it back
tpsReader = vtk.vtkMNITransformReader()
if (tpsReader.CanReadFile(filename) != 0):
tpsReader.SetFileName(filename)
thinPlate = tpsReader.GetTransform()
# make a linear transform
linearTransform = vtk.vtkTransform()
linearTransform.PostMultiply()
linearTransform.Translate(-127.5, -127.5, 0)
linearTransform.RotateZ(30)
linearTransform.Translate(+127.5, +127.5, 0)
# remove the linear part of the thin plate
tpsGeneral = vtk.vtkGeneralTransform()
tpsGeneral.SetInput(thinPlate)
tpsGeneral.PreMultiply()
tpsGeneral.Concatenate(linearTransform.GetInverse().GetMatrix())
# convert the thin plate spline into a grid
transformToGrid = vtk.vtkTransformToGrid()
transformToGrid.SetInput(tpsGeneral)
transformToGrid.SetGridSpacing(16, 16, 1)
transformToGrid.SetGridOrigin(-64.5, -64.5, 0)
transformToGrid.SetGridExtent(0, 24, 0, 24, 0, 0)
transformToGrid.Update()
gridTransform = vtk.vtkGridTransform()
gridTransform.SetDisplacementGridConnection(
transformToGrid.GetOutputPort())
gridTransform.SetInterpolationModeToCubic()
# add back the linear part
gridGeneral = vtk.vtkGeneralTransform()
gridGeneral.SetInput(gridTransform)
gridGeneral.PreMultiply()
gridGeneral.Concatenate(linearTransform.GetMatrix())
# invert for reslice
gridGeneral.Inverse()
# write to a file
gridWriter = vtk.vtkMNITransformWriter()
gridWriter.SetFileName("mni-grid.xfm")
gridWriter.SetComments("TestMNITransforms output transform")
gridWriter.SetTransform(gridGeneral)
gridWriter.Write()
# read it back
gridReader = vtk.vtkMNITransformReader()
gridReader.SetFileName("mni-grid.xfm")
transform = gridReader.GetTransform()
# apply the grid warp to the image
reslice = vtk.vtkImageReslice()
reslice.SetInputConnection(blend.GetOutputPort())
reslice.SetResliceTransform(transform)
reslice.SetInterpolationModeToLinear()
# set the window/level to 255.0/127.5 to view full range
viewer = vtk.vtkImageViewer()
viewer.SetInputConnection(reslice.GetOutputPort())
viewer.SetColorWindow(255.0)
viewer.SetColorLevel(127.5)
viewer.SetZSlice(0)
viewer.Render()
try:
os.remove("mni-grid.xfm")
except OSError:
pass
try:
os.remove("mni-grid_grid.mnc")
except OSError:
pass
try:
os.remove(filename)
except OSError:
pass
except IOError:
print "Unable to test the writer/reader."
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