title: CGContextDrawImage in Retina draws image pixelated?
body: <p>I need to draw images into a CALayer because I need to perform various effects, animations and filters on it. When I do simple drawing into the CGContext no matter what I do it always gets drawn pixelated... 
  What's the right way to draw onto a context in retina?</p>
  
  <p>This is what I'm doing now:</p>
  
  <pre><code>CGImageRef plateImage = [[UIImage imageNamed:@"someImage"] CGImage];
  CGFloat width = CGImageGetWidth(plateImage), height = CGImageGetHeight(plateImage);
  CGFloat scale = [[UIScreen mainScreen] scale];
  
  NSLog(@"Scale: %f\nWidth: %f\nHeight: %f", scale, width, height);
  CGContextTranslateCTM(_context, 0, height / scale);
  CGContextScaleCTM(_context, 1.0, -1.0);
  
  CGContextDrawImage(_context, CGRectMake(0, 0, width / scale, height / scale), plateImage);
  </code></pre>