void RandomHue(const cv::Mat& in_img, cv::Mat* out_img,

               const float hue_prob, const float hue_delta) {

  float prob;

  caffe_rng_uniform(, .f, .f, &prob);

  if (prob < hue_prob) {
　　 以一定概率进行色调调整

    CHECK_GE(hue_delta, ) << "hue_delta must be non-negative.";

    float delta;

    caffe_rng_uniform(, -hue_delta, hue_delta, &delta);

    AdjustHue(in_img, delta, out_img);

  } else {

    *out_img = in_img;

  }

}

void AdjustHue(const cv::Mat& in_img, const float delta, cv::Mat* out_img) {

  if (fabs(delta) > ) {

    // Convert to HSV colorspae.

    cv::cvtColor(in_img, *out_img, CV_BGR2HSV);

    // Split the image to 3 channels.

    vector<cv::Mat> channels;

    cv::split(*out_img, channels);

    // Adjust the hue.

    channels[].convertTo(channels[], -, , delta);

    cv::merge(channels, *out_img);

    // Back to BGR colorspace.

    cvtColor(*out_img, *out_img, CV_HSV2BGR);

  } else {

    *out_img = in_img;

  }

}

void RandomContrast(const cv::Mat& in_img, cv::Mat* out_img,

    const float contrast_prob, const float lower, const float upper) {

  float prob;

  caffe_rng_uniform(, .f, .f, &prob);

  if (prob < contrast_prob) {

    CHECK_GE(upper, lower) << "contrast upper must be >= lower.";

    CHECK_GE(lower, ) << "contrast lower must be non-negative.";

    float delta;

    caffe_rng_uniform(, lower, upper, &delta);

    AdjustContrast(in_img, delta, out_img);

  } else {

    *out_img = in_img;

  }

}

void AdjustContrast(const cv::Mat& in_img, const float delta,

                    cv::Mat* out_img) {

  if (fabs(delta - .f) > 1e-) {

    in_img.convertTo(*out_img, -, delta, );

  } else {

    *out_img = in_img;

  }

}