支持iOS 6.0 and later

    CIContext *context = [CIContext contextWithOptions:nil];        CIImage *inputImage = [[CIImage alloc] initWithImage:[UIImage imageNamed:@"1.png"]];        // create gaussian blur filter        CIFilter *filter = [CIFilter filterWithName:@"CIGaussianBlur"];        [filter setValue:inputImage forKey:kCIInputImageKey];        [filter setValue:[NSNumber numberWithFloat:10.0] forKey:@"inputRadius"];        // blur image        CIImage *result = [filter valueForKey:kCIOutputImageKey];        CGImageRef cgImage = [context createCGImage:result fromRect:[result extent]];        UIImage *image = [UIImage imageWithCGImage:cgImage];        CGImageRelease(cgImage);        self.mainImageView.image = image;