magick_mess.rb

# draws a random polygon (with absolute size!) of a random color and transparency

def rand_poly
  "-fill \"rgba(#{rand()*100}, #{rand()*100}, #{rand()*100}, #{rand()})\" -stroke none -draw \"polyline #{rand(640)},#{rand(480)} #{rand(640)},#{rand(480)} #{rand(640)},#{rand(480)} #{rand(640)},#{rand(480)}\" "
end


# drop some random polygons onto the stupid wizard logo image
`convert logo: #{rand_poly} #{rand_poly} #{rand_poly} logo.tif`

# compare the original to the new image, and report the root mean squared error
`compare -verbose -metric RMSE logo: logo.tif logodiff.tif`

# show me both the new messy one and the result of `compare`
`open logo.tif`
`open logodiff.tif`