title: Optimization methods for iOS pdf render slowness
body: <p>I have a pdf reader app which render the pdf file. It works fine for normal pdf files. But for some of big magazine files, it's really slow to render a page. Then I tried to upload my pdf file to GoodReader, it's slightly better than my app, but it's also very slow. That means this kind of pdf really need to be optimized before it's used for iOS device. </p>
  
  <p>I've tried the Adobe Acrobat 10 to reduce the file size, but the the result is not very obvious. And I have another similar magazine pdf is rendered pretty fast in my reader. But I can't tell the difference. I think there must be some key factors will affect the pdf rendering. But unfortunately I have no idea at all. </p>
  
  <p>Can anybody advise how to optimize pdf file? Are there any good software for that? Thanks</p>