Rotate UIImage/CGImageRef

UIImage+Rotation

- (UIImage *)rotateImage:(UIImage *)image ofAngle:(CGFloat)degrees {
    CGImageRef imgRef = image.CGImage;
  CGFloat angleInRadians = degrees * (M_PI / 180);
	CGFloat width = CGImageGetWidth(imgRef);
	CGFloat height = CGImageGetHeight(imgRef);
	
	CGRect imgRect = CGRectMake(0, 0, width, height);
	CGAffineTransform transform = CGAffineTransformMakeRotation(angleInRadians);
	CGRect rotatedRect = CGRectApplyAffineTransform(imgRect, transform);
	
	CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
	CGContextRef bmContext = CGBitmapContextCreate(NULL,
												   rotatedRect.size.width,
												   rotatedRect.size.height,
												   CGImageGetBitsPerComponent(imgRef),
												   0,
												   colorSpace,
												   kCGImageAlphaPremultipliedFirst);
	CGContextSetAllowsAntialiasing(bmContext, NO);
	CGContextSetInterpolationQuality(bmContext, kCGInterpolationNone);
	CGColorSpaceRelease(colorSpace);
	CGContextTranslateCTM(bmContext,
						  +(rotatedRect.size.width/2),
						  +(rotatedRect.size.height/2));
	CGContextRotateCTM(bmContext, angleInRadians);
	CGContextDrawImage(bmContext, CGRectMake(-width/2, -height/2, width, height),
					   imgRef);
	
	CGImageRef rotatedImage = CGBitmapContextCreateImage(bmContext);
	CFRelease(bmContext);
	
    UIImage *finalImage = [UIImage imageWithCGImage:rotatedImage];
    CFRelease(rotatedImage);
    
	return finalImage;
}