2つの画像のxorをとるテスト

xor_image.rb

require 'chunky_png'

# 画像サイズと色の種類は同じと仮定
image1 = ChunkyPNG::Image.from_file('sample1.png')
image2 = ChunkyPNG::Image.from_file('sample2.png')
xor_image = ChunkyPNG::Image.new(image1.width, image1.height, ChunkyPNG::Color::TRANSPARENT)

image1.height.times do |h|
  image2.width.times do |w|
    # 0xff透過色を無視
    xor_image[w, h] = image1[w, h] ^ image2[w, h] | 0xff
  end
end

xor_image.save('xor_image.png')