func blurImage(_ image: UIImage) -> UIImage {
        let context = CIContext (options:  nil )
        let  inputImage = CIImage (image: image)
        //使用高斯模糊滤镜
        let  filter  =  CIFilter (name:  "CIGaussianBlur" )!
        filter.setValue(inputImage, forKey:kCIInputImageKey)
        //设置模糊半径值（越大越模糊）
        filter.setValue(30, forKey: kCIInputRadiusKey)
        let  outputCIImage =  filter.outputImage!
        let  rect =  CGRect (origin:  CGPoint .zero, size: image.size)
        let  cgImage = context.createCGImage(outputCIImage, from: rect)
        //显示生成的模糊图片
        let newImage =  UIImage (cgImage: cgImage!)
        return newImage
}