Image-based Water Level Measurement Method under Stained Ruler

作     者：Jae-do KIM Young-joon HAN Hern-soo HAHN 

作者机构：Dept.of Electronic EngineeringSoongsil UniversitySeoul 156-743Korea 

出 版 物：《Journal of Measurement Science and Instrumentation》 (测试科学与仪器（英文版）)

年 卷 期：2010年第1卷第1期

页      面：28-31页

学科分类：08[工学] 080203[工学-机械设计及理论] 0802[工学-机械工程] 

基　　金：supported by the Brain Korea 21 Project in 2010,the MKE(The Ministry of Knowledge Economy,Korea) the ITRC(Information Technology Research Center)support program(NIPA-2010-(C1090-1021-0010)) 

主　　题：water level measurment image processing surveillancesystem histogram analysis 

摘      要：This paper propoes the water level measuring method based on the image, while the ruler used to indicate the water level is stained. The contamination of the ruler weakens or eliminates many features which are required for the image processing. However, the feature of the color difference between the ruler and the water surface are firmer on the environmental change compare to the other features. As the color differeaces are embossed, only the region of the ruler is limited to eliminate the noise, and the average image is produced by using several continuous frames. A histogram is then produced on the height axis of the produced intensity average image. Local peaks and local valleys are detected, and the section between the peak and valley which have the greatest change is looked for. The valley point at this very moment is used to detect the water level. The detected water level is then converted to the actual water level by using the mapping table. The proposed method is compared to the ultrasonic based method to evaluate its accuracy and efficiency on the various contaminated environments.