Method TextColorString

tensorflow/lite/toco/dump_graphviz.cc:88–93

The color to use for this node; will be used as 'fillcolor' for its box. See Color::AsHexString. A suitable, different color will be chosen for the 'fontcolor' for the inside text label, see Color::TextColorString. Returns the serialization in graphviz format of a suitable color to use 'fontcolor' in the same boxes. It should black or white, whichever offers the better contrast from AsHexString().

  // 'fontcolor' in the same boxes. It should black or white, whichever offers
  // the better contrast from AsHexString().
  string TextColorString() const {
    // https://en.wikipedia.org/wiki/Relative_luminance
    const float luminance = 0.2126f * r_ + 0.7152f * g_ + 0.0722f * b_;
    const uint8 l = luminance > 128.f ? 0 : 255;
    return StringF("#%.2X%.2X%.2X", l, l, l);
  }

 private:
  uint8 r_ = 0, g_ = 0, b_ = 0;