title: How to save image as progressive image using paperclip?
body: <p>How to save image as progressive image using paperclip/Imagemagick?</p>
  
  <p>Code I am using:</p>
  
  <pre><code>has_attached_file :photo, {
        :styles =&gt; {
            :medium =&gt; ["200x200#", :jpg] ,
            :small =&gt; ["192x256#", :jpg], 
            :thumb =&gt; ["50x50#", :jpg],
            :small_thumb =&gt;["30x30#", :jpg] 
          },
          :convert_options =&gt; { 
            :medium =&gt; "-quality 60",
            :small =&gt; "-quality 60",
            :thumb =&gt; "-quality 60",
            :small_thumb =&gt; "-quality 60" 
          },
        :default_url =&gt; "/assets/default_:style.png" }.merge(PAPERCLIP_STORAGE_OPTIONS)
  </code></pre>