title: MKOverlay View is blurred
body: <p>I'm trying to add a png image as a custom map using MKOverlayView. I'm almost there - I am able to get the image lined up in the right place, and I know that the -drawMapRect: method in the subclass of MKOverlayView is being called periodically; I just can't seem to get the image to render properly. It's totally blurry, almost beyond recognition. I also know the image is large enough (it is 1936 × 2967). Here is my code for -drawMapRect:</p>
  
  <pre><code>- (void)drawMapRect:(MKMapRect)mapRect zoomScale:(MKZoomScale)zoomScale inContext:(CGContextRef)context{
  
  
      // Load image from applicaiton bundle
      NSString* imageFileName = [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:@"map.jpg"];
      CGDataProviderRef provider = CGDataProviderCreateWithFilename([imageFileName UTF8String]);
      CGImageRef image = CGImageCreateWithJPEGDataProvider(provider, NULL, true, kCGRenderingIntentDefault);
      CGDataProviderRelease(provider);
  
      // save context before screwing with it
      CGContextSaveGState(context);
      CGContextScaleCTM(context, 1.0, -1.0);
      CGContextSetAlpha(context, 1.0);
  
      // get the overlay bounds
      MKMapRect theMapRect = [self.overlay boundingMapRect];
      CGRect theRect = [self rectForMapRect:theMapRect];
  
      // Draw image
      CGContextDrawImage(context, theRect, image);
      CGImageRelease(image);
      CGContextRestoreGState(context);
  </code></pre>
  
  <p>Does anyone have a clue what's going on?</p>
  
  <p>Thanks!
     -Matt</p>