UIImageview 模糊、高斯模糊

         CIContext *context = [CIContext contextWithOptions:nil];

// 加载本地图片  uiimage imagename:@""。    CIImage *image = [[CIImage alloc] initWithCGImage.CGImage];

      CIImage *image = [CIImage imageWithContentsOfURL:[NSURL URLWithString:@"www.123.jpg";

         CIFilter *filter = [CIFilterfilterWithName:@"CIGaussianBlur"];

        [filter setValue:image forKey:kCIInputImageKey];

// 设置模糊值

        [filter setValue:@20.0f forKey: @"inputRadius"];

        CIImage *result = [filter valueForKey:kCIOutputImageKey];

        CGImageRef outImage = [context createCGImage: result fromRect:[result extent]];

        UIImage * blurImage = [UIImage imageWithCGImage:outImage];

／／headerBGimage 是uiimageview

        headerBGimage.image = blurImage;