def calc_iou_wh(box1_wh, box2_wh):
    """
    param box1_wh (list, tuple): Width and height of a box
    param box2_wh (list, tuple): Width and height of a box
    return (float): iou
    """
    min_w = min(box1_wh[0], box2_wh[0])
    min_h = min(box1_wh[1], box2_wh[1])
    area_r1 = box1_wh[0] * box1_wh[1]
    area_r2 = box2_wh[0] * box2_wh[1]
    intersect = min_w * min_h
    union = area_r1 + area_r2 - intersect
    return intersect / union