image_text.rb

# Something I have wanted to write for a while, 
# takes text and converts to an image, very simple.
# Erick Schmitt - July 19, 2009

module ImageText
  require 'rubygems'
  require 'fileutils'
  require 'RMagick'
  include Magick

  def self.render(image_text, file_name = nil, user_options = {}, return_image = false)

    options = {
      :margin => 10, #[0, 0, 0, 0], # margin - css style
      :background_color => 'white',
      :color => 'black',
      :font_weight => 100,
      :font_family => 'Helvetica',
      :font => nil,
      :font_size => 32
    }

      options.merge! user_options

      default_file_name = image_text.gsub(/[^a-z0-9]/i,'_').squeeze('_').chomp('_') + '.png'

      if File.directory? file_name
        file_name = File.join file_name, default_file_name
      end

      file_name = default_file_name unless file_name    

      canvas = Magick::Image.new(300, 300){ self.background_color = 'transparent' }

      text = Magick::Draw.new
      text.font_family = options[:font_family]
      text.font = options[:font] if options[:font]
      text.font_weight = options[:font_weight]
      text.pointsize = options[:font_size]
      text.gravity = Magick::CenterGravity

      text.annotate(canvas, 0,0,0,0, image_text) {
        self.fill = options[:color]
      }

      canvas.trim!(true)

      # the remaining code is just to apply a margin...
      margin = options[:margin]
      margin = Array.new(4,margin) if margin.kind_of? Fixnum
      img_height = canvas.rows + margin[0] + margin[2]
      img_width = canvas.columns + margin[1] + margin[3]
      canvasBG = Magick::Image.new(img_width, img_height){ self.background_color = options[:background_color] }
      canvasBG.composite!(canvas, margin[3], margin[0], Magick::OverCompositeOp)

      # save it
      canvasBG.write(file_name) { self.quality = 100 }

      return file_name unless return_image
      return [canvasBG, file_name]

  end


end

# example:
# input_text = ARGV[0]
# ImageText.render(input_text, 'text.png', {:color => "#990000", :background_color => 'transparent'})