static double video_scoreRect_score(Rect expected, Rect guessed, double tolerance) {
  if ((guessed == null) != (expected == null)) ret 0;
  if (expected == null) ret 1;
  ret clamp(1-doubleAverage(
    ptDistance(rectCenter(guessed), rectCenter(expected)),
    abs(guessed.w-expected.w),
    abs(guessed.h-expected.h))
    /tolerance, 0, 1);
}