create_image_with_str.rb

GC.disable
before = `ps -o rss= -p #{Process.pid}`.to_i

require 'bundler/setup'
require 'mini_magick'

OUTPUT = "output.png"
MATERIAL = "material.png"
FONT_PATH = '/Library/Fonts/Osaka.ttf'
BACKGROUND_COLOR = "#000000"

labels = [
 {label: "山田 太郎",    pos: "+110+165", size: "14"},
 {label: "5 4 1",      pos: "+93+183", size: "20"},
 {label: "0 0 4 4",    pos: "+154+183", size: "20"},
 {label: "大阪市 中央区", pos: "+100+226", size: "14"},
 {label: "伏見町 4-4-9", pos: "+100+247", size: '14'},
 {label: "06",          pos: '+110+207', size: '14'},
 {label: "7878",        pos: "+150+207", size: '14'},
 {label: "6838",        pos: '+180+207', size: '14'},
 {label: "吉田 篤",      pos: '+110+267', size: '14'},
]

MiniMagick::Tool::Convert.new do |convert|
  convert << "sample.gif"
  convert << OUTPUT
end

labels.each do |label|
  MiniMagick::Tool::Convert.new do |convert|
    convert.instance_eval do
      fill(BACKGROUND_COLOR)
      font(FONT_PATH)
      transparent(BACKGROUND_COLOR)
      label(label[:label])
      pointsize(label[:size])
      self << MATERIAL
    end
  end
  MiniMagick::Tool::Convert.new do |convert|
    convert << OUTPUT
    convert << MATERIAL
    convert.geometry(label[:pos])
    convert.composite
    convert << OUTPUT
  end
end
after = `ps -o rss= -p #{Process.pid}`.to_i
p after - before

使用メモリ量は概ね 28kb 程度