Update label according to padding region

def _update_labels(self, label, pad_box, height, width):
        """Update label according to padding region"""
        out = label.copy()
        out[:, (1, 3)] = (out[:, (1, 3)] * width + pad_box[0]) / pad_box[2]
        out[:, (2, 4)] = (out[:, (2, 4)] * height + pad_box[1]) / pad_box[3]
        return out