ForHenry.m

- (UIImage *)createBlurredGrayscaleScreenshotWithRange:(int)blurRange {
	NSDate *now = [NSDate date];
	FTLOG(@"%f: %@", [now timeIntervalSinceNow], NSStringFromSelector(_cmd));
	UIGraphicsBeginImageContext(self.bounds.size);
	[self.layer renderInContext:UIGraphicsGetCurrentContext()];
	UIImage *viewImage = UIGraphicsGetImageFromCurrentImageContext();
	UIGraphicsEndImageContext();

	CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceGray();
	int bitsPerComponent = CGImageGetBitsPerComponent([viewImage CGImage]);
	int bytesPerRow = CGImageGetBytesPerRow([viewImage CGImage]);
	//  CGBitmapInfo bmpInfo = CGImageGetBitmapInfo([viewImage CGImage]);

	CGContextRef context = CGBitmapContextCreate(NULL, viewImage.size.width, viewImage.size.height, 
	                                             bitsPerComponent, bytesPerRow, colorSpace, kCGImageAlphaNone);

	CGLayerRef cgLayer = CGLayerCreateWithContext(context, viewImage.size, NULL);
	CGContextRef layerContext = CGLayerGetContext(cgLayer);
	CGRect imgRect = CGRectZero;
	imgRect.size = viewImage.size;

	CGContextSetAlpha(layerContext, (CGFloat)1.f/blurRange);
	CGContextDrawImage(layerContext, imgRect, [viewImage CGImage]);

	FTLOG(@"%f: START Draw Layers", [now timeIntervalSinceNow], NSStringFromSelector(_cmd));
	CGContextSaveGState(context);
	CGContextDrawLayerAtPoint(context, CGPointZero, cgLayer);
	for (int i=1; i<blurRange; i++) {
	  CGFloat blurPoint = (CGFloat)i/(blurRange/2.f);
	  CGContextDrawLayerAtPoint(context, CGPointMake(blurPoint, blurPoint), cgLayer);
	  CGContextDrawLayerAtPoint(context, CGPointMake(-blurPoint, -blurPoint), cgLayer);
	}
	CGContextRestoreGState(context);
	FTLOG(@"%f: DONE Draw Layers", [now timeIntervalSinceNow], NSStringFromSelector(_cmd));

	CGLayerRelease(cgLayer);

	CGImageRef cgimg = CGBitmapContextCreateImage(context);
	UIImage *newImage = [UIImage imageWithCGImage:cgimg];
	CGImageRelease(cgimg);
	CGContextRelease(context);
	CGColorSpaceRelease(colorSpace);
	FTLOG(@"%f: %@", [now timeIntervalSinceNow], NSStringFromSelector(_cmd));
	return newImage;
}