iOS - Safe way to blur a UIImage - ios

Question

In the past we had two different ways of blurring UIImages, and both led to crashes for our users. The first way crashes when the user puts the device into background (GPU error, not allowed to do anything in background).
The second one crashes with ESC_BAD_ACCESS errors.
What's a better (crash-safe) way to do it?
Version 1:
- (UIImage *)blurred:(float)inputRadius {
// create our blurred image
CIContext *context = [CIContext contextWithOptions:nil];
CIImage *inputImage = [CIImage imageWithCGImage:self.CGImage];
// setting up Gaussian Blur (we could use one of many filters offered by Core Image)
CIFilter *filter = [CIFilter filterWithName:#"CIGaussianBlur"];
[filter setValue:inputImage forKey:kCIInputImageKey];
[filter setValue:[NSNumber numberWithFloat:inputRadius] forKey:#"inputRadius"];
CIImage *result = [filter valueForKey:kCIOutputImageKey];
CGImageRef cgImage = [context createCGImage:result fromRect:[inputImage extent]];
UIImage *blurredImage = [UIImage imageWithCGImage:cgImage];
CFRelease(cgImage);
return blurredImage;
}
Version 2:
- (UIImage*)blurredImage:(CGFloat)blurRadius {
if (blurRadius < 0.0) {
blurRadius = 0.0;
}
CGImageRef img = self.CGImage;
CGFloat inputImageScale = self.scale;
vImage_Buffer inBuffer, outBuffer;
vImage_Error error;
void *pixelBuffer;
CGDataProviderRef inProvider = CGImageGetDataProvider(img);
CFDataRef inBitmapData = CGDataProviderCopyData(inProvider);
inBuffer.width = CGImageGetWidth(img);
inBuffer.height = CGImageGetHeight(img);
inBuffer.rowBytes = CGImageGetBytesPerRow(img);
inBuffer.data = (void*)CFDataGetBytePtr(inBitmapData);
pixelBuffer = malloc(CGImageGetBytesPerRow(img) * CGImageGetHeight(img));
outBuffer.data = pixelBuffer;
outBuffer.width = CGImageGetWidth(img);
outBuffer.height = CGImageGetHeight(img);
outBuffer.rowBytes = CGImageGetBytesPerRow(img);
CGFloat inputRadius = blurRadius * inputImageScale;
if (inputRadius - 2. < __FLT_EPSILON__)
inputRadius = 2.;
uint32_t radius = floor((inputRadius * 3. * sqrt(2 * M_PI) / 4 + 0.5) / 2);
radius |= 1; // force radius to be odd so that the three box-blur methodology works.
// line of crash
error = vImageBoxConvolve_ARGB8888(&inBuffer, &outBuffer, NULL, 0, 0, radius, radius, NULL, kvImageEdgeExtend);
if (!error) {
error = vImageBoxConvolve_ARGB8888(&outBuffer, &inBuffer, NULL, 0, 0, radius, radius, NULL, kvImageEdgeExtend);
}
if (error) {
return self;
}
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
CGContextRef ctx = CGBitmapContextCreate(outBuffer.data,
outBuffer.width,
outBuffer.height,
8,
outBuffer.rowBytes,
colorSpace,
(CGBitmapInfo)kCGImageAlphaNoneSkipLast);
CGImageRef imageRef = CGBitmapContextCreateImage (ctx);
UIImage *returnImage = [UIImage imageWithCGImage:imageRef];
CGContextRelease(ctx);
CGColorSpaceRelease(colorSpace);
free(pixelBuffer);
CFRelease(inBitmapData);
CGImageRelease(imageRef);
return returnImage;
}