Research On Wave Contour Measurement Based On Binocular Vision

In the application background of reduce wave resistance and increase the speed of the ship,based on the research object of the waves that produced by the ship model motion in the pool of Harbin Engineering University.Then analysis the wave waveform and draw its contour map.In the experiment,key techniques in binocular stereo vision technology including feature points detecting,stereo matching and 3D reconstruction are explored and researched in depth.The prime research task content is as follows:1.In feature point detection section,an improved algorithm based on combination of Harris corner detection algorithm and SIFT algorithm is proposed.Use Harris corner detection algorithm to extract the feature corners at different scales of space on the image and keep the candidate corners which can be found at the same location in different scale space.Then use the approach of determining the direction in SIFT algorithm to accuracy screen the candidate corners,the remaining points is the scale-invariant feature points.This algorithm will not only overcome the problem that the number of detected corners is less when using SIFT algorithm only,but also eliminate the problem that Harris corner detection algorithm does not have the quality of scale invariance.Finally,generate descriptors using SIFT algorithm for stereo matching in order to improve the matching rate.2.In stereo matching section,using a combination of multi-constraint method.Use the epipolar constraint to find the candidate matching corners and coarse screen them with fixed search area and eigenvalues ratio constraints.Then use the disparity gradient constraint and the maximum vector angle criterion to accuracy screen the candidate matching corners,and ultimately achieve the purpose of matching one by one.3.In 3D reconstruction section,Use the approach of making some special marks on the boat or water and record the relative position between them.With the relationship,the transfer matrix between the camera world coordinate system and the horizontal world coordinate system can be calculated.Then the 3D coordinates that calculated by the principle of Binocular measurement can be transferred to the horizontal world coordinate system,and then draw wavy contour map.