Script intended for use with Hazel to resize/optimize web images based on directives in image filenames

autooptim.rb

#!/usr/bin/ruby
# Brett Terpstra <http://brettterpstra.com>

=begin 
Example:
> file1@2x%%ohc.png
=> Converts png to jpeg, creates 1x and 2x versions, optimizes both with jpegoptim

Available directives:

  %%[och]rXXX[xXXX]
  o => optimize image
  c => convert png to jpg
  h => create a half size image (remove @2x or add _sm)
  rXXX[xXXX] => resize to max-width or WxH

Requires jpegoptim, pngcrush, and convert (ImageMagick)
=end
require 'fileutils'

ARGV.each do |arg|
  input = File.expand_path(arg)
  Process.exit 1 unless File.exists?(input)
  extension = File.extname(input)
  filename = File.basename(input,extension)
  folder = File.dirname(input)

  if filename =~ /%%/
    targets = []
    m = filename.match(/%%([hcor\dx]+)$/)

    unless m.nil?
      directives = m[1]
      filename.sub!(/%%[hcor\dx]+$/,'')

      if directives =~ /c/ && extension =~ /\.png/i
        target = File.join(folder,filename+".jpg")
        print "Converting #{input} -> #{target}... "
        res = system %Q{/usr/local/bin/convert "#{input}" -background white -flatten  -alpha off "#{target}" &> /dev/null}
        if res
          puts "OK"
          FileUtils.mv input, File.expand_path("~/.Trash"), :force => true
          extension = ".jpg"
          input = target
          targets.push(target)
        else
          puts "ERROR"
          Process.exit 1
        end
      else
        target = File.join(folder, filename+extension)
        FileUtils.cp input, File.expand_path("~/.Trash")
        FileUtils.mv input, target, :force => true
        input = target
        targets.push(target)
      end



      if directives =~ /r(\d+(x(\d+))?)/
        width = $1
        dim = $2.nil? ? "#{width}x#{width}" : "#{width}x#{$3}"
        if filename =~ /@2x$/ && directives =~ /h/
          size = (width.to_i / 2).to_s
          puts "#{width} / 2 = #{size}"
        else
          size = width.to_s
          puts "Fullsize = #{size}"
        end
        filename.sub!(/(@2x)?$/,"-#{size}\\1")
        resized = File.join(folder, filename + extension)
        print "Resizing #{input} to #{dim} -> #{resized}... "
        res = system %Q{/usr/local/bin/convert "#{input}" -adaptive-resize #{dim} "#{resized}" &> /dev/null}
        if res
          puts "OK"
          FileUtils.mv input, File.expand_path("~/.Trash"), :force => true
          targets.delete(input)
          targets.push(resized)
          input = resized
        else
          puts "ERROR"
          Process.exit 1
        end
      end

      if directives =~ /h/
        if filename =~ /@2x$/
          halfsize = File.join(folder, filename.sub(/@2x$/,'') + extension)
        else
          halfsize = File.join(folder, filename + "_sm" + extension)
        end
        print "Halving #{input} -> #{halfsize}... "
        puts %Q{/usr/local/bin/convert "#{input}" -adaptive-resize 50% "#{halfsize}" &> /dev/null}
        res = system %Q{/usr/local/bin/convert "#{input}" -adaptive-resize 50% "#{halfsize}" &> /dev/null}
        if res
          puts "OK"
          targets.push(halfsize)
        else
          puts "ERROR"
          Process.exit 1
        end
      end

      if directives =~ /o/
        targets.each do |target|
          print "Optimizing #{target}... "
          if target =~ /\.jpe?g$/i && File.exists?('/usr/local/bin/jpegoptim')
            res = system %Q{/usr/local/bin/jpegoptim -fopt --strip-all -m80 -T10 "#{target}" &> /dev/null}
          elsif target =~ /.png$/i && File.exists?('/usr/local/bin/pngcrush')
            res = system %Q{/usr/local/bin/pngcrush -q -ow "#{target}" &> /dev/null}
          end
          puts res ? "OK" : "ERROR"
        end
      end
    end
  end
end

Thanks for this, Brett. I have extended it slightly to allow originals to kept, which I find helpful when working with photos. I'm not very familiar with github gists, but have forked it to https://gist.github.com/jgclark/2f82e4a27a6157d5608cfc122b26891f with this extension.

@jgclark 👍