@implementation UIImage (scale)

/**
 * Scales an image to fit within a bounds with a size governed by
 * the passed size. Also keeps the aspect ratio.
 *
 * Switch MIN to MAX for aspect fill instead of fit.
 *
 * @param newSize the size of the bounds the image must fit within.
 * @return a new scaled image.
 */
- (UIImage *)scaleImageToSize:(CGSize)newSize {
  
  CGRect scaledImageRect = CGRectZero;
  
  CGFloat aspectWidth = newSize.width / self.size.width;
  CGFloat aspectHeight = newSize.height / self.size.height;
  CGFloat aspectRatio = MIN ( aspectWidth, aspectHeight );
  
  scaledImageRect.size.width = self.size.width * aspectRatio;
  scaledImageRect.size.height = self.size.height * aspectRatio;
  scaledImageRect.origin.x = (newSize.width - scaledImageRect.size.width) / 2.0f;
  scaledImageRect.origin.y = (newSize.height - scaledImageRect.size.height) / 2.0f;
  
  UIGraphicsBeginImageContextWithOptions( newSize, NO, 0 );
  [self drawInRect:scaledImageRect];
  UIImage* scaledImage = UIGraphicsGetImageFromCurrentImageContext();
  UIGraphicsEndImageContext();
  
  return scaledImage;
  
}

@end