ABSTRACT
An important part of playing golf is ability to hit the ball with distance and accuracy. A good score depends on the golfer’s skill as well as high performance equipment. To improve skill, the golfer may take lessons from an instructor. However, there are many golfers who cannot take lessons because of lack of time or the high cost. To reduce the cost and time for improving a golfer’s game, a system that automatically diagnoses the golfer’s swing has been developed. Swing analysis requires identification of the desired points of reference in the golfer’s swing or “form.” A computer analysis of the form is then automatically generated. Image analysis systems have been used in various types of sports to analyze form. However, it is difficult to analyze the form by hand. Recently, a motion capture system (Nakagawa & Moorhouse, 2004) was developed which accurately analyzed the form automatically. The measurement accuracy of this system is high, and the system is suitable for research on golf swing kinematics. However, since two or more special cameras are needed, it is difficult to set up the system in a typical golf retail shop. Moreover, this system can only analyze the position where an image analysis mark is attached to the golfer. A motion capture system which employs one camera (Fukui et al., 2002) was developed. This system requires that all the positions in the swing image to be identified. The types of swings that can be analyzed are limited since it is difficult to specify the swing positions and their colors may darken or become invisible while the swing is being made. The system proposed in this paper utilizes two cameras and specially marked clothing. The system does not require that all the positions (such as joints) in the swing image to be recorded, but selects the set of images necessary to make the swing diagnosis. It then combines and processes two or more images to estimate the positions required to make the analysis, even if the marks are hidden. The unique feature of the system is that it can generate the required points of reference in locations where there are no markers. In addition, the system makes swing and corrective practice recommendations based on the Dunlop Training Program (Sumitomo Rubber Industries, 1994).
