View Full Version : Olympic Biomechanical Data update

Gideon Ariel
07-31-1996, 02:48 PM
Dear Subscriber:
Our web site is overwhelmed with responses to our posting of the
Olympic video data on the net with more then 1000 downloads recorded in the
last 24 hours! As you know, this is the first time in modern Olympic
history that the Internet is used to upload biomechanical data to a web site
available for the whole world to use at no cost. This allows multiple
locations around the Planet Earth to analyze performances and create a
global database of biomechanical data.
Since the 1968 Olympic Games in Mexico City through the Games in
Munich, Montreal, Los Angeles, Seoul, and Barcelona, the medium we used to
collect the data was initially 16 mm film followed by the next camera
advance which was video. In the 1968 Mexico City Games, the 3D analytic
technique required cameras to be placed orthogonally. There have been major
advances in biomechanical procedures since that time! The Munich Games were
analyzed using orthogonal camera locations but in Montreal, we used the DLT
algorithm for the first time. In Los Angeles in 1984, we used the Internet
for the first time, however, we had to use Unix which provided less than
full flexibility in downloading video files. Here in Atlanta, we are
utilizing more modern technologies. Analog and digital video cameras are
utilized to record the events and then the data is downloaded to notebook
computers. Immediately after the data is stored on hard disk, it is
uploaded via cellular phone to our web site. Cyberspace technology is
really amazing and exciting!
The activities available to date are: Discus (women), Hammer, High
Jump (men), Hurdles (110 women), Javelin (women), Long jump (men), and
Triple jump (men). The Triple Jump includes all three components - hop,
step, and jump - since the requested data reflects interest concerning the
loss of horizontal speed. This information can be studied by digitizing
only 2 points on the body. Today we will upload the Women Triple Jump and
the Men Discus.
There have been a few questions concerning the method we are using.
(1) Original files usually exceed 10 MB in size and must be compressed.
A special algorithm is utilized which compresses only the part which is
moving while the background remains unchanged. This allow us to have up to
50/1 compression ratio. Of course, the clarity of the video is compromised
to some extent but these files can quickly be downloaded and processed. You
can obtain these files from the http://www.arielnet.com/download/Olympics
sub directory. We have the original, uncompressed files which are of
excellent viewing quality. Some of you have requested the original which we
can download to your ftp site.
(2)Calibration frames and measurements will be available soon. At the
moment, known objects on the field must be used for transformation.
(3)The file format is AVI which is the standard Microsoft Video format.
AVI files can be loaded frame by frame for digitizing.
Please let us know if you have any questions, suggestions, or comments.
Gideon Ariel, Ph.D.