The Research Of Digital Image Technique For Watergate Displacement Automatic Detection

Watergate displacement detection is one of the most important parts in automatic control system for Watergate. In the past ten years, encoder has been widely used in the detection to the Watergate displacement, and video supervisory has been widely used in automatic control system for watergate. As a result, an auto Watergate displacement detection model established on the digital image processing has been researched and discussed.Taking Nanjing LiShui TianSheng Bridge Watergate for instance, the realization of an auto watergate displacement detection model established on the digital image processing has been introduced. Making use of the video supervisory equipments of the automatic control system for watergate, using CCD cameras to record the movements video of watergate, picking up the pictures in a certain frame frequency, after pretreatments to these pictures, combining the frame difference method and background subtraction, the motion target in complex scenes can be detected. The motion part of the watergate can be obtained by the subtraction between two sequential pictures. The accurate and real-time background can be obtained via the alteration on the traditional algorithm of background subtraction. Profile projection has been applied to detect the precise locations of pixels on the picture on every sampling spot. Aimed at the certain slope of the motion target, edge detection technique and Hough transformation has been applied to figure out the slope angle between the target and horizontal direction. A solution based on a lookup table is used to transform the displacement between the pixel locations and the real ones. The value of its application has been proved by the experiments.The software of system was programmed by Visual C++6.0 and Matlab, which can make the best of the Matlab toolbox and interior functions, combine the advantage of VC programming and shorten the period of software development.