为实现水位的实时精确监测，提出了一种基于视频图像的水位监测方法，该方法不识别水尺刻度与数字，而是利用水尺刻度对相机进行标定，用图像差分法提取水位变化区域，计算图像水位线坐标，根据相机标定结果算得实际水位高度。该方法算法简便、处理速度快、满足实时监测要求、受水尺刻度限制及污渍等外界环境的影响较小，可以较精确测得水位高度。研究选用两幅分辨率为 640×480的图像进行模拟实验，在图像未满足要求的情况下测得水位平均误差小于0.5cm，当系统满足设计要求时测量精度会进一步提高，该方法可以较好地实现水位的实时精确监测。

In order to achieve real-time and accurate monitoring of the water level, a water level monitoring method based on image processing is proposed. Instead of recognizing the water gauge scale and numbers, the method uses the water gauge scale to calibrate the camera. It extracts the water level change area with the image difference method, calculates the image water level line coordinates, and obtains the actual water level height according to the camera calibration result. The method is simple in algorithm and fast in processing speed, thus it meets the requirements of real-time monitoring, and is less affected by the external environment such as water ruler scale limitation and stain, and can accurately measure the water level height. Two 640×480 pictures were selected for simulation experiments. An average water level error of less than 0.5cm was obtained when the image does not meet the requirements, but if the system meets the design requirements, the measurement accuracy will be further improved. The method can better realize real-time accurate monitoring of the water level.