ios 屏幕截图

    // 高斯模糊
    CIContext *context = [CIContext contextWithOptions:nil];
    CIImage *inputImage = [[CIImage alloc] initWithImage:image];
    CIFilter *filter = [CIFilter filterWithName:@"CIGaussianBlur"];
    [filter setValue:inputImage forKey:kCIInputImageKey];
    [filter setValue:@2.0f forKey: @"inputRadius"];
    CIImage *result = [filter valueForKey:kCIOutputImageKey];
    CGImageRef outImage = [context createCGImage: result fromRect:[result extent]];
    UIImage *blurImage = [UIImage imageWithCGImage:outImage];
    CGImageRelease(outImage);