title: Batch optimization of PNGs for iphone/ipad display as xcode does
body: <p>I'm working on a magazine viewer for ipad and I'm struggling with the performance.</p>
  
  <p>I figured out that the most expensive part of displaying the pngs is the loading process.
  I know that xcode is able to optimize pngs during the build and such images are loaded much faster.  But I can't include all images in to the build as it will be huge.</p>
  
  <p>Do you know how to optimize an arbitrary png without including it in the build process?</p>
  
  <p>Do you know what is the best format for iphone? I think that pngs should use RGB-8888 color scheme but I'm not sure what else is important.</p>
  
  <p>Maybe you know exact params for imagemagick?</p>