ImageCorrelation
Repository source: ImageCorrelation
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Code¶
ImageCorrelation.py
#!/usr/bin/env python3
# noinspection PyUnresolvedReferences
import vtkmodules.vtkInteractionStyle
# noinspection PyUnresolvedReferences
import vtkmodules.vtkRenderingOpenGL2
from vtkmodules.util.execution_model import select_ports
from vtkmodules.vtkCommonColor import vtkNamedColors
from vtkmodules.vtkImagingCore import vtkImageCast, vtkImageShiftScale
from vtkmodules.vtkImagingGeneral import vtkImageCorrelation
from vtkmodules.vtkImagingSources import vtkImageCanvasSource2D
from vtkmodules.vtkInteractionStyle import vtkInteractorStyleImage
from vtkmodules.vtkRenderingCore import (
vtkImageActor,
vtkRenderer,
vtkRenderWindow,
vtkRenderWindowInteractor
)
def main():
colors = vtkNamedColors()
# Create an image.
draw_color1 = colors.GetColor3ub('Black')
draw_color2 = colors.GetColor3ub('Wheat')
image_source = vtkImageCanvasSource2D(extent=(0, 300, 0, 300, 0, 0), number_of_scalar_components=3)
image_source.SetScalarTypeToUnsignedChar()
image_source.draw_color = tuple(draw_color1)
image_source.FillBox(0, 300, 0, 300)
image_source.draw_color = tuple(draw_color2)
image_source.FillTriangle(10, 100, 190, 150, 40, 250)
image_source.update()
# Create an actor.
original_actor = vtkImageActor()
image_source >> original_actor.mapper
# Create a kernel.
kernel_source = vtkImageCanvasSource2D(extent=(0, 30, 0, 30, 0, 0), number_of_scalar_components=3)
kernel_source.SetScalarTypeToUnsignedChar()
kernel_source.draw_color = tuple(draw_color1)
kernel_source.FillBox(0, 30, 0, 30)
kernel_source.draw_color = tuple(draw_color2)
kernel_source.FillTriangle(10, 1, 25, 10, 1, 5)
kernel_source.Update()
# Create an actor.
kernel_actor = vtkImageActor()
kernel_source >> kernel_actor.mapper
# Compute the correlation.
correlation_filter = vtkImageCorrelation()
image_source >> select_ports(0, correlation_filter)
kernel_source >> select_ports(1, correlation_filter)
correlation_filter.update()
# At this point, corr pixels are doubles so, get the scalar range.
corr = correlation_filter.output
corr_range = corr.point_data.scalars.range
scale = 255 / corr_range[1]
# Rescale the correlation filter output. Note that it implies that
# minimum correlation is always zero.
image_scale = vtkImageShiftScale(scale=scale, input_connection=correlation_filter.output_port)
image_scale.SetOutputScalarTypeToUnsignedChar()
correlation_cast_filter = vtkImageCast()
correlation_cast_filter.SetOutputScalarTypeToUnsignedChar()
# Create an actor.
correlation_actor = vtkImageActor()
correlation_filter >> image_scale >> correlation_cast_filter >> correlation_actor.mapper
# Define viewport ranges (x_min, y_min, x_max, y_max).
original_viewport = (0.0, 0.0, 0.33, 1.0)
kernel_viewport = (0.33, 0.0, 0.66, 1.0)
correlation_viewport = (0.66, 0.0, 1.0, 1.0)
# Setup the renderers.
original_renderer = vtkRenderer(viewport=original_viewport, background=colors.GetColor3d('Mint'))
original_renderer.AddActor(original_actor)
kernel_renderer = vtkRenderer(viewport=kernel_viewport, background=colors.GetColor3d('Mint'))
kernel_renderer.AddActor(kernel_actor)
correlation_renderer = vtkRenderer(viewport=correlation_viewport, background=colors.GetColor3d('Peacock'))
correlation_renderer.AddActor(correlation_actor)
# Set up the render window.
render_window = vtkRenderWindow(size=(900, 300), window_name='ImageCorrelation')
render_window.AddRenderer(original_renderer)
render_window.AddRenderer(kernel_renderer)
render_window.AddRenderer(correlation_renderer)
# Set up the render window interactor.
render_window_interactor = vtkRenderWindowInteractor()
style = vtkInteractorStyleImage()
render_window_interactor.interactor_style = style
# Render and start the interaction.
render_window_interactor.render_window = render_window
render_window.Render()
render_window_interactor.Initialize()
render_window_interactor.Start()
if __name__ == '__main__':
main()