title: Mirroring CIImage/NSImage
body: <p>Currently I have the following</p>
  
  <pre><code> CIImage *img = [CIImage imageWithCVImageBuffer: imageBuffer];
  
   NSCIImageRep *imageRep = [NSCIImageRep imageRepWithCIImage:img];
   NSImage *image = [[[NSImage alloc] initWithSize: [imageRep size]] autorelease];
   [image addRepresentation:imageRep];
  </code></pre>
  
  <p>This works perfectly, I can use the NSImage and when written to a file the image is exactly how I need it to be. </p>
  
  <p>However, I'm pulling this image from the users iSight using QTKit, so I need to be able to flip this image across the y axis.</p>
  
  <p>My first thought was to transform the CIImage using something like this, however my final image always comes out completely blank. When written to a file the dimensions are correct but it's seemingly empty.</p>
  
  <pre><code>- (CIImage *)flipImage:(CIImage *)image
  {
      return [image imageByApplyingTransform:CGAffineTransformMakeScale(-1, 1)];
  }
  </code></pre>
  
  <p>Am I approaching this the wrong way? Or have I made a mistake in my code?</p>