Sensors, Vol. 19, Pages 4141: Visual Measurement of Water Level under Complex Illumination Conditions

Sensors, Vol. 19, Pages 4141: Visual Measurement of Water Level under Complex Illumination Conditions
Sensors doi: 10.3390/s19194141
Authors:
Zhang
Zhou
Liu
Zhang
Wang

Image-based water level measurement is a visual-sensing technique which automatically inspects the reading of the water line via image processing instead of the human eye. It can be realized easily on an existing video surveillance system and has advantages like low cost, non-contact, as well as results that are verifiable. It has the potential to be widely used in flood and waterlogging monitoring, while facing the challenge that water-line detection under complex natural or artificial illumination conditions is quite difficult in field applications. To handle this problem, a method is proposed assuming that the water line is generally located on the row with the largest local change of gray or edge features in the image of the water gauge. The water line is determined by coarse-to-fine detection of the position of the maximum mean difference (MMD) of the horizontal projections of gray and edge images. Image-based flow-level measurement systems were developed at two measurement sites. In situ comparative experiments were conducted with the float-type stage gauge and other image-based methods. The results show that the fusion of gray and edge features can overcome the shortcomings of single feature methods under complex illumination conditions such as dim light, glares, shadows and artifici...

Source: Sensors - September 23, 2019 Category: Biotechnology Authors: Zhang Zhou Liu Zhang Wang Tags: Article Source Type: research