    #! /usr/local/bin/ruby -w
    require 'RMagick'

    # Demonstrate the Image#colorize method by converting
    # a full-color image to "sepia-tone"

    polynesia = Magick::Image.read('images/Polynesia.jpg').first
    polynesia = polynesia.scale(300.0/polynesia.rows)

    # Convert the color image to monochrome
    mono = polynesia.quantize(256, Magick::GRAYColorspace)

    # Colorize with a 20% blend of a brownish-orange color
    colorized = mono.colorize(.2, .2, .2, 'orange3')

    # Do the usual before-and-after composite. Draw a line down the middle.
    colorized = colorized.crop(colorized.columns/2,0,colorized.columns,colorized.rows)
    polynesia = polynesia.composite(colorized, Magick::EastGravity, Magick::OverCompositeOp)

    line = Magick::Draw.new
    line.line(polynesia.columns/2, 0, polynesia.columns/2, polynesia.rows)
    line.draw(polynesia)

    #polynesia.display
    polynesia.write('colorize.jpg')
    exit