Args:
        boxes: kx4
        scores: kxC

def draw_predictions(img, boxes, scores):
    """
    Args:
        boxes: kx4
        scores: kxC
    """
    if len(boxes) == 0:
        return img
    labels = scores.argmax(axis=1)
    scores = scores.max(axis=1)
    tags = ["{},{:.2f}".format(cfg.DATA.CLASS_NAMES[lb], score) for lb, score in zip(labels, scores)]
    return viz.draw_boxes(img, boxes, tags)