some problem about matchingscore

[Githubpfyang]

hi, zlingkang
i have read your code, and i have one question about matchingscore
why use this:
int score = static_cast((1.0-iou) * dx * dy * 100.0 / (_rec1.width * _rec1.height));
as the matchingscore instead of just iou ?
which can be more accurate?