#!/usr/bin/ruby -w

# Matt Comi
# www.bigbucketblog.com
# Usage: oscillofy INPUT_IMAGE OUTPUT_PCM
# Your input image should be 255x255 and black and white (not grayscale) for 
# best results.
# The resultant PCM will be 8-bit unsigned.
# RMagick is required.

require 'RMagick'

include Magick

if ARGV.length != 2
    print "Usage: oscillofy.rb INPUT_IMAGE OUTPUT_PCM\n"
else
    image = Image::read(ARGV[0]).first;

    image.resize!(255, 255)

    pixels = image.get_pixels(0, 0, image.columns, image.rows)

    f = File.new(ARGV[1], "w+")

    arr = Array.new()

    arrayIndex = 0

    image.rows.times do |y|
        image.columns.times do |x|        
            index = image.columns * y + x

            pixel = pixels[index]

            if pixel.red != 255 && pixel.green != 255 && pixel.blue != 255
                # flip it vertically
                arr << 255 - y
                arr << x
            end
        end
    end

    data = arr.pack("C*")

    f.write(data)    
end