title: UIImage RenderingMode : UIImageRenderingModeAutomatic vs UIImageRenderingModeAlwaysOriginal vs UIImageRenderingModeAlwaysTemplate
body: <p>I have come across the <code>UIImage</code> property <code>UIImageRenderingMode</code> which is introduced in iOS 7. But I don't get the differences among different <code>UIImageRenderingMode</code>s that are <code>UIImageRenderingModeAutomatic</code>, <code>UIImageRenderingModeAlwaysOriginal</code> and <code>UIImageRenderingModeAlwaysTemplate</code>.</p>
  
  <p>I want to know the basic meaning of them and when/how to use them.</p>