Research On Automatic Table Tennis Scoring Method Based On Video Detection

Table tennis,the "national ball" in people's public fitness program is widely popular in China.However,people usually play table tennis and need other people to score.When people are not enough,they need to be distracted to score.The purpose of this dissertation is to use the computer to detect and track the table tennis to design a method that can automatically score in the process of competition to make scoring more accurate and display the score in real-time to solve the problem of traditional manual collecting work.It not only costs time but also makes trouble.It provides convenience and fun for people in follow-up sport activities.Based on reading a lot of references,the analysis of video image detection technology,using the image pixel coordinate system to establish two dimensional image model,design and implement a complete table tennis automatic scoring algorithm.In this paper,we use the mobilephone camera with the wide-angle lens to obtain a valid video data samples.The format conversion and frame processing of the collected video are carried out.In this paper,we use Visual Studio and Open CV to process a series of image preprocessing.The color image is grayscale processed,and the median filtering method is used in the image enhancement part.In the threshold segmentation process,we use the Otsu method to determine the threshold of the image binarization,and then make the morphological operations such as erosion and corrosion to the image.In this paper,we compare and analysis three methods to find the ball.Finally,the method of interframe difference and target shape matching are used to realize the recognition and localization of table tennis according to the actual effect.At the same time,using Canny operator on the ping-pong table for edge detection,the use of neighborhood search method to achieve the ping-pong table contour coordinates extraction.Then,set up effective area and extract the effective outline,calculate the centroid coordinates of table tennis in every frame image according to centroid coordinates formula.Finally,according to the coordinates position of the center-of-mass of the ping-pong ball and the flight trajectory analysis in each turn,the relevant decisions about the starting position of table tennis,flight direction,out of bounds,the case of the hit and the ball under the net are determined.The results and the reasons for the display,to achieve the effect of automaticlly scoring.For the accuracy of algorithm for detecting table tennis and automatic scoring method,we analyzed the reasons of the existence of error,at the same time put forward for improving the accuracy and reduc ing the error.We make the further outlook.