db.addFace = async function(imageName, tileLocation, ffd) {
  return await db.faces.add({
    'image_name':imageName,
    'tile_x':tileLocation.x,
    'tile_y':tileLocation.y,
    'x':ffd.detection.box.x,
    'y':ffd.detection.box.y,
    'w':ffd.detection.box.width,
    'h':ffd.detection.box.height,
    'score':ffd.detection.score,
    'descriptor':ffd.descriptor,
    'landmarks': ffd.landmarks,
    'expressions': ffd.expressions
  });
};