SphinxExamples/src/Filtering/ImageFeature/DetectEdgesWithCannyFilter/Code.py

#!/usr/bin/env python
 
# Copyright NumFOCUS
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#        http://www.apache.org/licenses/LICENSE-2.0.txt
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
 
import sys
import itk
 
if len(sys.argv) != 6:
    print("Usage: " + sys.argv[0] + " <InputImage> <OutputImage> "
          "<Variance> <LowerThreshold> <UpperThreshold>")
    sys.exit(1)
 
inputImage = sys.argv[1]
outputImage = sys.argv[2]
variance = float(sys.argv[3])
lowerThreshold = float(sys.argv[4])
upperThreshold = float(sys.argv[5])
 
InputPixelType = itk.F
OutputPixelType = itk.UC
Dimension = 2
 
InputImageType = itk.Image[InputPixelType, Dimension]
OutputImageType = itk.Image[OutputPixelType, Dimension]
 
reader = itk.ImageFileReader[InputImageType].New()
reader.SetFileName(inputImage)
 
cannyFilter = itk.CannyEdgeDetectionImageFilter[
    InputImageType,
    InputImageType].New()
cannyFilter.SetInput(reader.GetOutput())
cannyFilter.SetVariance(variance)
cannyFilter.SetLowerThreshold(lowerThreshold)
cannyFilter.SetUpperThreshold(upperThreshold)
 
rescaler = itk.RescaleIntensityImageFilter[
    InputImageType,
    OutputImageType].New()
rescaler.SetInput(cannyFilter.GetOutput())
rescaler.SetOutputMinimum(0)
rescaler.SetOutputMaximum(255)
 
writer = itk.ImageFileWriter[OutputImageType].New()
writer.SetFileName(outputImage)
writer.SetInput(rescaler.GetOutput())
 
writer.Update()