Function GetTopDetections

tensorflow/examples/multibox_detector/main.cc:187–210

Analyzes the output of the MultiBox graph to retrieve the highest scores and their positions in the tensor, which correspond to individual box detections.

// Analyzes the output of the MultiBox graph to retrieve the highest scores and
// their positions in the tensor, which correspond to individual box detections.
Status GetTopDetections(const std::vector<Tensor>& outputs, int how_many_labels,
                        Tensor* indices, Tensor* scores) {
  auto root = tensorflow::Scope::NewRootScope();
  using namespace ::tensorflow::ops;  // NOLINT(build/namespaces)

  string output_name = "top_k";
  TopK(root.WithOpName(output_name), outputs[0], how_many_labels);
  // This runs the GraphDef network definition that we've just constructed, and
  // returns the results in the output tensors.
  tensorflow::GraphDef graph;
  TF_RETURN_IF_ERROR(root.ToGraphDef(&graph));

  std::unique_ptr<tensorflow::Session> session(
      tensorflow::NewSession(tensorflow::SessionOptions()));
  TF_RETURN_IF_ERROR(session->Create(graph));
  // The TopK node returns two outputs, the scores and their original indices,
  // so we have to append :0 and :1 to specify them both.
  std::vector<Tensor> out_tensors;
  TF_RETURN_IF_ERROR(session->Run({}, {output_name + ":0", output_name + ":1"},
                                  {}, &out_tensors));
  *scores = out_tensors[0];
  *indices = out_tensors[1];
  return Status::OK();
}

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