CoreImage GaussianBlur

blurImage

+(UIImage *)blurImage:(UIImage *)image withStrength:(float)strength
{
    CIContext *context = [CIContext contextWithOptions:nil];
    CIImage *inputImage = [[CIImage alloc] initWithCGImage:image.CGImage];
    CIFilter *filter = [CIFilter filterWithName:@"CIGaussianBlur"];
    [filter setValue:inputImage forKey:@"inputImage"];
    [filter setValue:[NSNumber numberWithFloat:strength] forKey:@"inputRadius"];
    
    CIImage *result = [filter valueForKey:kCIOutputImageKey];
    float scale =  [[UIScreen mainScreen] scale];
    CIImage *cropped=[result imageByCroppingToRect:CGRectMake(0, 0, image.size.width*scale, image.size.height*scale)];
    CGRect extent = [cropped extent];
    CGImageRef cgImage = [context createCGImage:cropped fromRect:extent];
    
    return [UIImage imageWithCGImage:cgImage];
}