No Programming, No Life
Jan 17, 2017 • 2 min read

Generate Square Thmumblnail by mini_magick[Ruby]

In this article, I would like to show a sample code to generate square thumbnail image by using Minimagick which is a Ruby wrapper for ImageMagic.


Installation

Add the gem to your Gemfile & run bundle install:

gem 'mini_magick'

Ruby Code

In a sample source, I will show you following flow:

require 'open-uri'
require 'mini_magick'

class ImageOptimizer
  class << self
    def resize(content, width, height, quality, output_path)
      img = MiniMagick::Image.read(content)
      w_original = img[:width].to_f
      h_original = img[:height].to_f

      # check proportions
      op_resize = if w_original * height < h_original * width
                    "#{width.to_i}x"
                  else
                    "x#{height.to_i}"
                  end

      img.combine_options do |i|
        i.resize(op_resize)
        i.gravity(:center)
        i.quality quality.to_s if quality.to_i > 1 && quality.to_i < 100
        i.crop "#{width.to_i}x#{height.to_i}+0+0!"
      end

      img.write(output_path)
    end
  end
end

URL = "http://farm4.staticflickr.com/3319/3584524809_f791a000e0_z.jpg"
OUT_PUT_FILE_PATH = './out_thumb.jpg'
WIDTH = 300
HEIGHT = 300
QUALITY = 80

content = open(URL)
resized_content = ImageOptimizer.resize(content, WIDTH, HEIGHT, QUALITY, OUT_PUT_FILE_PATH)

So, it is operation confirmation.

Another dog

The above image(640x480) was converted to the following square image(300x300):

Happy Hacking!

API Document

Documentation for minimagick/minimagick

Special Thanks