title: ImageQuality with CGContextSetInterpolationQuality
body: <p>How effective is the <code>CGContextSetInterpolationQuality</code> method in Quartz?</p>
  
  <p>Does it affect the quality of the image? If so, to what extent?</p>
  
  <p>I can't see any difference between the interpolated and the non-interpolated image.</p>