Research On Automatic Detection Method And Application Of Spatial Curve

Curve detection is the key technology of image recognition and analysis,it is widely used in industrial automation,public safety,supervision and attendance,traffic safety,national defense and other fields.The common methods of curve detection include cluster analysis method,arc segment combination method,geometric feature method,Hough transform and Randomized Hough transform etc.In this paper,the detection algorithm of line,circle and ellipse based on Hough transform and Randomized Hough transform are studied,the following is the main content:Firstly,the detection principle and algorithm of Hough transform and Randomized Hough transform are introduced.The algorithm is applied to line detection by using MATLAB programming,then the advantages and disadvantages of the algorithm are obtained by comparing the performance of the algorithm.Secondly,the problem of detecting complex circle is studied.By comparing and analyzing the circle detection principle and algorithm of Hough transform and Randomized Hough transform,the results show that the detection performance of Randomized Hough transform is better than that of Hough transform.Then,the algorithmic accuracy of detection circle by Randomized Hough transform is analyzed by numerical experiments.The algorithm can get the correct results occasionally,but still has the disadvantage of low detection accuracy.Therefore,an improved algorithm is proposed.The algorithm determines the proper threshold by calculating the average error.These points on the circles of the average error surpasses the threshold are removed,and done Randomizedized Hough transform again until all circles are detected.A large number of experiments show that the detection accuracy of the improved algorithm is better than that of the standard Randomized Hough transform in the circle detection.Finally,the ellipse detection is studied.By analyzing the geometric characteristics of ellipse,the method of detecting ellipse by Hough transform exposed two problems.One is low detection efficiency caused by a large number of parameters;The other is a huge amountof computation because Hough transform makes up the mappings of one to many,and needs to quantify the parameter space.In this paper,the maximum distance method and Randomized Hough transform are used to solve the problems,but the effect is still not ideal.In order to further improve the accuracy of detecting ellipse by Randomized Hough transform,and shorten the detection time,this paper presents an improved algorithm based on the window,that is to select the appropriate window and rotate a certain angle,fitting in all points in the window.And then check the algorithm until all ellipses detected.And to judge the ellipse is whether or not the true one by test algorithm.The simulated and real images results show that the improved algorithm improves the efficiency of ellipse detection.