random_threshold_channel.rb

#!/usr/bin/ruby -w

# Demonstrate the random_channel_threshold method

require 'RMagick'

img = Magick::Image.read('images/Flower_Hat.jpg').first

geom = Magick::Geometry.new(Magick::QuantumRange/2)
img2 = img.random_threshold_channel(geom, Magick::RedChannel)

img2.write('random_threshold_channel.jpg')
exit
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