title: How to use kCGImagePropertyGIFImageColorMap or create a color table?
body: <p>I'm trying to tinker with a couple GIF properties such as <code>kCGImagePropertyGIFImageColorMap</code> and <code>kCGImagePropertyGIFHasGlobalColorMap</code> (<a href="https://developer.apple.com/library/mac/#documentation/GraphicsImaging/Reference/CGImageProperties_Reference/Reference/reference.html" rel="nofollow noreferrer">reference</a>) in Core Graphics.</p>
  
  <p>I'm creating animated GIFs and I'd like to see if I can improve the quality by playing with the amount of colors. I've only found <a href="https://stackoverflow.com/questions/6147672/core-graphics-gif-color-table">one other code sample</a> and I'm not sure it works.</p>
  
  <p>I've tried using a couple sample codes linked above, but it doesn't seem to work. Nor does setting the <code>kCGImagePropertyGIFHasGlobalColorMap</code> seem to do anything. Thanks</p>