2012, Volume 4, Issue 3
Application of the AS-4 Software in Research on Players’ Kinematics on a Large Area in 3D Coordinates As an Alternative to Commercial Programs
Piotr Aschenbrenner1, Patrycja Lipińska1, Włodzimierz S. Erdmann1
1Gdansk University of Physical Education and Sport in Gdansk
Author for correspondence: Patrycja Lipińska; Gdansk University of Physical Education and Sport in Gdansk; email: patlip[at]awf.gda.pl
Background: In this work an original computer program for the video analysis of players on a large area by using a single camera is presented. Video analysis is one of the basic research techniques of human movement applied in sport. A set of cameras and special computer software is used for this purpose. Many companies provide hardware and software, but, unfortunately, their high cost and difficulty in usage are their major drawbacks. In order to simplify and reduce the costs of data analysis (obtained from a single camera), AS-4 program was developed.
Material/Methods: The program includes an original algorithm which enables positioning of the camera in any place. Specifying dimensions of the playing field and an object, the program automatically calculates a scale and transfers the data to the 3D matrix. Then, using flat transformation, 3D coordinates can be determined.
Results: The algorithm was tested in the field. The accuracy of determining coordinates was studied in 3 areas and errors of the method were within an acceptable range.
Conclusions: With the present program, it was possible to determine the kinematic parameters at any time during the movement. The accuracy of the program was sufficient to determine the 3D position. It can be used to determine the movement path over a large area and then to calculate velocity and acceleration.
Key words: photogrammetry, video analysis, 3D motion trajectory, optical geometry