Any golfer would confirm it: Mastering the perfect swing is a matter of practice and patient training. Professional golfers have been using video recordings for some time to analyze their swing in detail and improve it. With the system "Swing & See" developed by R&D Vision (www.rd-vision.com) of France, amateurs now have access to this technology and can benefit from a powerful analysis tool on the golf course in their neighborhood. The system relies on Pike F-032B cameras from Allied Vision Technologies (Ahrensburg, Germany; www.alliedvisiontec.com) to capture and precisely document each phase of the swing movement.
It has, of course, always been possible for any golfer to have themselves filmed by a friend with a camcorder to analyze their mistakes. Although this method may provide some help, it offers limited analysis capabilities: The image quality depends on the quality of the camera used and the skills of the person operating it. Furthermore, recordings cannot be viewed properly on site without an appropriate display. They may include movement artifacts and show the action only from one view angle.
R&D Vision, a R&D company that specializes in advanced imaging solutions, has developed the "Swing & See" tutorial tool for its client V2S. The system consists of an interactive terminal that houses the control unit and image processing combined with two AVT Pike digital cameras and a color touch-screen display. The whole set is permanently installed on the golf practice tee and is weather-proof for outdoor installation.
The movement of the swinging golfer is captured by the two cameras simultaneously at 200 frames/s. The cameras are positioned with a 90-degree angle to each other in order to record the action simultaneously from the front and the side. The high frame rate and short shutter time (<500 µs) enable sharp images of every single step of the movement. The start of recording is automatically and simultaneously triggered by image-processing software able to identify the position of the ball. Thus, the whole swing process is precisely captured from both view angles.
As soon as a shot has been recorded, the player can watch his or her swing on the display. A didactic tool allows slow motion control for an image-by-image replay in order to detect the slightest imperfection. Graphic markings can be added on the picture to help assess the swing motion; comparison mode compares the player's performance with that of a professional instructor (or one's earlier motion) stored in the system memory.
After the training, the golfer can save all data (video file, assessment of the swing, speed of the ball, etc.) on a digital storage device such as a USB drive or memory card. That way, he can archive his performance at home on his PC to follow up on his progress or further analyze the video recording at home with companion software available for download on the web site of the service provider.
"For that project, a high frame rate and a short shutter time were key to ensure precise, high-quality recordings which are crucial for the ongoing analysis," says Arnaud Susset, CEO of R&D Vision.
R&D Vision was counseled in the choice and integration of the cameras by Stemmer Imaging France (Suresnes, France; www.imasys.fr), a machine-vision specialist in France formerly known as IMASYS. A member of the STEMMER Imaging Group, Stemmer Imaging France is AVT's local partner in that country. The image-processing application developed by R&D Vision relies on Stemmer's Common Vision Blox library (CVB).
V2S is already investigating opportunities to adapt the system to other sports such as practicing the serve in tennis.
