thresholdn.门槛；开端；界限；入口threshold logic阈逻辑,阈值逻辑threshold pricen.最低价格；起点价格threshold shift听觉阈值差,阈移位,阈移threshold alarm阚值告警threshold cross阈交threshold point门限点threshold field阈场threshold value阈值threshold range门限范围threshold image二值化图像