title: Resizing animated GIF using GraphicsMagick
body: <p>I have an animated <code>gif</code> image with transparent frames.
  I need to resize it.</p>
  
  <p>Before resizing, I use the <code>Magick::coalesceImages</code> function, after I resize the image I use the <code>Magick::writeImages</code> function to collect all the <code>gif</code> frames back into one single image.</p>
  
  <p>The problem is that the output resized image file size is bigger than the original one, because the original animated <code>gif</code> had transparent frames, and the new resized <code>gif</code> does not have any transparent frames.</p>
  
  <p>I have read about frame optimization on <a href="http://www.imagemagick.org/Usage/anim_opt/#frame_opt" rel="nofollow">www.imagemagick.org</a> plus I can see on <a href="http://www.graphicsmagick.org/Magick++/Image.html" rel="nofollow">www.graphicsmagick.org</a> the <code>gifDisposeMethod</code> function.</p>
  
  <p>My question is, how can I cause the resized animated <code>gif</code> image to use transparency frames and avoid the increase on the image <code>KBytes</code> size? </p>