Function DecodeLocation

tensorflow/examples/multibox_detector/main.cc:214–234

Converts an encoded location to an actual box placement with the provided box priors.

// Converts an encoded location to an actual box placement with the provided
// box priors.
void DecodeLocation(const float* encoded_location, const float* box_priors,
                    float* decoded_location) {
  bool non_zero = false;
  for (int i = 0; i < 4; ++i) {
    const float curr_encoding = encoded_location[i];
    non_zero = non_zero || curr_encoding != 0.0f;

    const float mean = box_priors[i * 2];
    const float std_dev = box_priors[i * 2 + 1];

    float currentLocation = curr_encoding * std_dev + mean;

    currentLocation = std::max(currentLocation, 0.0f);
    currentLocation = std::min(currentLocation, 1.0f);
    decoded_location[i] = currentLocation;
  }

  if (!non_zero) {
    LOG(WARNING) << "No non-zero encodings; check log for inference errors.";
  }
}

float DecodeScore(float encoded_score) {
  return 1 / (1 + std::exp(-encoded_score));