Low Cost Baseball Detection and Three Dimension Trajectory Reconstruction System
| Autor: | Kai-Chun Chan, 詹凱鈞 |
|---|---|
| Rok vydání: | 2011 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 99 Baseball is one of the most popular sports in our country. A pitcher plays the major role in a baseball game. A good pitcher has to control his pitch precisely in order to be successful in the game. But the strike zone is up to the umpire's call. A strike or a ball called in a critical situation pitch can dramatically affect the result of a game. In MLB, they use K-Zone or similar system to analyze whether the pitched ball is a strike or a ball. These systems are attracting people who love baseball. But the system is too expensive to be available for simple training purpose. We try to implement such a system with the low cost in mind. Our system can reconstruct baseball three dimension trajectory in real time and judge automatically the pitched ball a strike or a ball. For reducing cost, we use inexpensive home-use cameras witch feed two image capture cards into two laptops. We use easily produced checkerboard pattern to calibrate the camera’s parameters. Two laptops connect by each other via Ethernet interface to exchange data. The moving objects near catcher are prone to be interfered, so we use Kalman filter to help the system estimate moving trajectory of baseball. The baseballs are detected in corresponding image points by two cameras and are used reconstruct baseball three dimension trajectory. We store the video information to database in the system. User can review the historical video and related information to help ball location analysis in the future. The experiment result shows that in the scenario of short distance the errors between the measured values of strike zone border and actual values of border are 0.31%, 1.57% and 0.51% respectively. This shows that our system is quite precise in short distance usage. The system performs the trajectory reconstruction and establishment of database requires 500ms. It can complete the program flow before the next pitch so that it can be used in live broadcast situation once we complete better GUI interface. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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