README.md

Yup, so just run mix run image.exs on this sucker. You'll have to open the image manually if you're on a mac, and hey, storing it in my home dir might not work either :)

image.exs

defmodule Image do
  @pixel_size 1
  @pixel_count 255*255*255
  @width 800
  @height 800
  @num_shades 50
  @colors for r <- 0..@num_shades,
              g <- 0..@num_shades,
              b <- 0..@num_shades,
              do: {r, g, b}
  @num_colors Enum.count(@colors)
  @pixel_positions for x <- 0..@width,
                       y <- 0..@height,
                       do: [x, y]

  def run do
    image = :egd.create(@width, @height)
    red = :egd.color({255, 0, 0})
    for [x, y] <- @pixel_positions do
      :egd.filledRectangle(image, {x, y}, {x, y}, :egd.color(Enum.at(@colors, x+y)))
      """
      :egd.filledRectangle(image, {x, y}, {x, y}, :egd.color({
        :crypto.rand_uniform(0, 255),
        :crypto.rand_uniform(0, 255),
        :crypto.rand_uniform(0, 255)
      }))
      """
    end
    :egd.save(:egd.render(image, :png), '/home/jadams/tmp/test.png')
  end
end

Image.run
System.cmd("gnome-open ~/tmp/test.png")