A New Style Ruler and Supporting Image Detection Algorithm for Urban Flood Water Level Measurement

In hydrographic survey field, image processing provides a reliable method for water level detection. However, traditional rulers do not suit image detection especially on condition that weak lights or some floating disturbs which all can affect image detection results. Furthermore, there are still some problems such as "0" water level misdetection and blurred water edge in urban flood supervision. Usually there are two ways to improve image detection results: one is to strive for good performance of image detection algorithm, the other is to design the ruler with notable characteristics for image recognition. This paper focuses on the latter because it can economically change traditional detection algorithms into more effective and robust ones. Through the skilled adoption of a geometric pattern for marking the calibrations on ruler and a freely moving dark floater, a synthesized design scheme is obtained and its supporting image detection algorithm is proposed simultaneously. Experiments accomplished indicate that new acquisitions do improve the image detection result for water level measurement. New ruler and its supporting image detection algorithm are likely to obtain widening application in flood or other water resource supervision and safety forecast.