View Full Version : Replies to Simple Video System

Rebecca A. States
01-09-1995, 09:08 AM
A few days ago I posted the following query.

> Hello fellow netters,
> Some colleagues and I want to set up a *SIMPLE* one-camera video system
> to track passive markers. We thought we'd use a single camera, reflective
> tape as markers, a frame grabber, and do the digitizing by hand. Is there
> software (commercial or otherwise) available to control the digitizing
> process and display the resulting kinematic data?
> Some time ago, I worked with such a system developed for a single lab at
> Hunter College in New York City, but I figure there must be other sources
> available by now. It must be user-friendly as we want it as a hands-on
> tool in an undergrad biomechanics course. We need to do basic things like
> show trajectories, velocity and acceleration profiles, compute joint angles,
> angular velocity, make angle/angle plots and stick figures. Additional
> features are welcome as long as they don't overly complicate the user
> interface.
> Thanks in advance for your help. I'll post the responses when they come in.
> Sincerely,
> Becky States

My summary of the replies is as follows.

1. Most people referred me to the well-known systems like PEAK, MacReflex,
Ariel Dynamics, or Motion Analysis. Each of these are comprehensive
systems that are probably beyond my budget ($10,000). I will check that
out personally. Contacts for these comprehensive systems and the others
systems referred to are:

Adelphi, MD
Phone: (301)434-0785

Ariel Dynamics
Phone: 714-858-4216
FAX: 714-858-0377

MacReflex & Selspot
Innovision Systems
30521 Schoenherr, Suite 104
Warren, MI 48093-3179
Phone: (810) 751-0600
FAX: 810-751-0646

Motion Analysis
(no contact given)

Motion Plus
Bill Hand for Qualisys
Phone: 707-579-2596

Peak Performance Inc.
7388 S. Revere Parkway, Suite 601
Englewood, Colorado, 80112
Phone: 303-799-8686
FAX: 303-799-8690

(not mentioned, but also offers comprehensive system)
Northern Digital
403 Albert St.
Waterloo, Ontario CANADA N2L 3V2
Phone: 800-265-2741
FAX: 519-884-5184

2. The first several postings refer to less comprehensive systems
which I presume are less expensive. Some are under development.

3. Other postings gave advice about the difficulties of creating
a system from scratch.

Thanks to everyone for their thoughts and suggestions. Reponses and
the original posting follow.


Becky States

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Rebecca A. States, Ph.D. 276H Read Building
Dept. of Health & Kinesiology (409) 862-3229
Texas A & M University (409) 847-8987 (fax)
College Station, Texas 77843-4243 states@tam2000.tamu.edu
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********** Responses to "Simple Video System" query *********************

From: BillH4740@aol.com
Date: Mon, 9 Jan 1995 11:45:14 -0500
To: states@tam2000.tamu.edu
Subject: Re: Simple Video System

Greetings Becky:
There is a 2D manual digitizing system available for the Macintosh. It is
called Motion Plus. It is developed by faculty members of the University of
Calgary, and it is distributed by Qualisys. Qualisys also has a 16
laboratory exercise series in biomechanics for undergraduate and graduate
courses in kinesiology and biomechanics developed by faculty at Utah State
University. Both products are very reasonably priced. Contact Bill Hand
(707-579-2596, BillH4740@aol.com) for product information.

Date: Fri, 6 Jan 1995 18:04:33 -0600 (CST)
From: Roy Allen Akers
To: "Rebecca A. States"
Subject: Re: Simple Video System

I am going to be creating just such software within the next year for 3
dimensional analysis. If I find that 2D analysis is used more than I had
thought, I may make a simpler spin-off to handle it exclusively. I will
let you know how it goes and would appreciate and video data you may be
able to provide me. I was considering a system that would use different
colored joint markers for each major joint, then you would pinpoint the
markers manually in the first frame and a fuzzy logic search pattern
would locate the markers on all succeeding frames. I am kinda by myself
up here working on biomechanics, so it is a slow, lonely process... :)


Allen Akers
University of North Texas
Dept of Kinesiology, Health Promotion, & Recreation

Date: Sat, 7 Jan 1995 15:43:44 -0700
To: "Rebecca A. States"
From: l.abraham@mail.utexas.edu (Larry Abraham)
Subject: Re: Simple Video System

Hi Becky:

What pieces of the system you plan to use do you already have? Are you
prepared to do the programming? In what language/environment? Are you
looking for automated or manual digitizing? What sort of graphics do you

We have some "home-grown" software we are currently revising which might be
what you want.

Larry Abraham, EdD
Kinesiology & Health Education
The University of Texas at Austin
Austin, TX 78712 USA
(512)471-1273 FAX (512)471-8914

Date: Sat, 07 Jan 95 13:07:37 EST
From: Mario Lamontagne PhD PErg
Subject: Re: Simple Video System
To: "Rebecca A. States"

We are working on the last version of a computer software to digitize
from video system controled by video grabber board.
As soon as the software will be ready I let you know

From: hinrichs@asu.edu
Date: Mon, 09 Jan 1995 14:51:10 -0700 (MST)
Subject: Re: Simple Video System
To: states@TAM2000.TAMU.EDU


Sounds like you used Bob Schleihauf's programs while you were at Hunter
College. I was going to suggest you contact Bob because he wrote just the
kind of program you are asking about. He and I were going to co-develop a
"poor-man's" video digitizing system when I first came to Arizona State in
1987. He had written the software and I was working on making the hardware
work. At the time, frame grabber boards were not as sophistocated as they
are today and I could not reliably get the system to work. I gave up and
bought a Peak Performance system. I'm not sure whether Bob has continued
the effort or not. You can always write the software yourself if you
have to. The trick is getting the hardware to work.


| Richard N. Hinrichs, Ph.D. | email: Hinrichs@ASU.EDU |
| Associate Professor | or Hinrichs@ESPE1.LA.ASU.EDU |
| Dept. of Exercise Science & PE | or atrnh@ACVAX.INRE.ASU.EDU |
| Arizona State University | Phone: (602) 965-1624 |
| Tempe, AZ 85287-0404 USA | FAX: (602) 965-8108 |

Date: Mon, 9 Jan 1995 09:04:19 -0600
From: fpollo@bcm.tmc.edu (Fabian Pollo)
To: states@tam2000.tamu.edu
Subject: Digitizing systems

Dear Dr. States,

Most commercial systems out there for digitizing markers from
video and computing parameters from that data are for multi-camera 2- and
3-dimensional systems and they are fairly expensive. For example the one
we use is call AMASS-PC from Adtech (Adelphi, MD (301)434-0785) and the
cost is $12,000. Your best bet is to look for some public domain
software. Good luck and call or e-mail me if you have any questions.

************************************************** ****************************
Fabian E. Pollo, Ph.D.
Assistant Professor
Director, Gait Laboratory
Baylor College of Medicine
Division of Restorative Neurology
and Human Neurobiology
Smith Tower, Suite 1901
6550 Fannin St.
Houston, Texas 77030
Phone: (713) 798-5536
Fax : (713) 798-5489
e-mail: fpollo@bcm.tmc.edu
************************************************** ****************************

Date: Fri, 6 Jan 1995 16:58:35 -0800
To: "Rebecca A. States"
From: bmunkasy@physics1.usc.edu (Barry Munkasy)
Subject: Re: Simple Video System

I'm sure you will get responses from Peak Performance Technologies,
Ariel Dynamics, and Motion Analysis. If not, let me know. How much
do you have to spend?

I would like to know what other companies are available besides the
three I listed, and also anything you find out about do it yourself

Barry Munkasy

To: states@tam2000.tamu.edu
From: "Selim Dogan"
Date: Mon, 9 Jan 1995 09:28:29 CDT
Subject: Re: Simple Video System

Hi Rebacca:

There are several video systems( peak5, expertvision etc.) available
in the market. I don't know the price of each system. You can
obtain all the kinematic data using Peak5. I used Peak5 for my
undergraduate Biomechanics course and I was pleased with
flexibility of the system. You can do filtering very easily and display
the stick figures with kinematic graphs ( joint angle, velocity etc.).
Time saving system. I had some problem with encoding the tape.
Maybe this problem has to with our old system.

Good luck and Happy New Year!

From: "Dr. Brian W. Bergemann"
To: states@tam2000.tamu.edu
Date: Mon, 9 Jan 1995 07:26:14 CDT
Subject: Videoanalysis

Hi Becky:

I recommend the Ariel Performance Analysis system. Via internet call
Gideon Ariel at GBARIEL@UCI.EDU

I am using this system for a biomechanics course and the students are
learning fairly quickly. I developed my own protocol sheets, which
are a step by step method of grabbing the video frames, transforming
the video coordinates to real dimensions or 3D dimensions if using
two cameras, smoothing the data with cubic splines, quintic splines,
filters, etc., viewing the digitized motion, graphing parameters
including displacement, velocity, acceleration linearly or angularly.
It is very powerful.

================================================== =======

Brian Bergemann, Ph.D. 205-626-3303
United States Sports Academy FAX: 205-626-1149
One Academy Drive
Daphne, AL 36526


================================================== =======

Date: Mon, 9 Jan 1995 00:10:20 -0500 (EST)
From: "Michael P. Poling"
Subject: Re: Simple Video System
To: "Rebecca A. States"

On Fri, 6 Jan 1995, Rebecca A. States wrote:

> available by now. It must be user-friendly as we want it for a hands-on
> tool in an undergrad biomechanics course. We need to do basic things like
> show trajectories, velocity and acceleration profiles, compute joint angles,
> angular velocity, make angle/angle plots and stick figures. Additional
> features are welcome as long as they don't overly complicate the user
> interface.

I've been using the PEAK 2D MOTION MEASURMENT SYSTEM at Lakehead
University where I assistant teach an undergraduate biomechanics course.
I used it as well in my undergraduate study. I've found it to be easy to
learn, implement and use on a daily basis. It's also complex enough to
have been used by Brian Boitano and other members of the United States
Figure Skating Association due it the easy of moving it from a 2D system
to a 3D system if need be...thus it is expandable.
The company making it is Peak Performance Technologies Inc. and they are
based in Colorado Springs.
Hope this helps.

Date: Mon, 9 Jan 1995 11:25:39 +1000
To: "Rebecca A. States"
From: C.Grant@LaTrobe.edu.au (Cameron Grant)
Subject: Re: Simple Video System

Hi Becky,

we are using the PEAK performance package (2D and 3D). It has the advantage
of being able to automate the digitizing of the markers (if you get the
automatic package). It will do all the things you want as a standard part
of it's programming.
Having said that...the user interface is mouse driven, and while I don't
have any problem with it myself, I am the technical officer for the group
who use it, and have been using it in a problem solving/teaching role for
about 3 years. I now pretty much know it inside out. New users on the other
hand *expect* to come in and use it without training, and without using
manuals. This is just not possible. It takes about 1 day concerted
teaching, a week semi-supervised (available to answer questions,
demonstrate the correct way), and then minor on-going support.
It does do what it claims to be able to do, it does do it through a
"relatively" friendly interface (ie pull down menus). It is not initially
particularly intuitive (at least not to begin with).
Also please note...due to the way that the video digitizing card that PEAK
have chosen, the computer digitizes 16 frames at a time, then rewinds the
tape and does the next 16 frames. If you intend to digitize a large number
of frames, then this could take some time.

Backup from PEAK has been good,and the system is expandable...You could do
worse!!! :)

Hope this helps

(o o) \|/
|Cameron D. Grant | Ph.Local: (03) 479 1724 |
|Department of Behavioural Health Sciences | Fax : 479 1783 |
|Latrobe University | |
|Bundoora Victoria, Australia 3083 | email : C.Grant@LATROBE.EDU.AU|

Date: Mon, 9 Jan 1995 09:22:32 +0200
To: "Rebecca A. States"
From: Tec.Serv@Latrobe.edu.au (Technical Services Unit, Carlton)
Subject: Re: Simple Video System

What you suggest is the ultimate goal of many equipment manufacturers in
this field. Some of the recent postings from Ariel et al testify to the
difficulties with VCRs and frame grabbers. The technology might be ready
soon but it is not as easy as it seems.

Unless you really want several years of development work and have the
software/hardware resources to do it, buy something readymade.

I would suggest "MacReflex" as a basic, single camera based system. It has
a user-friendly interface and is easy to run. It should give you the data
calculation required.

Remember that a single camera input to a storage device doesn't allow
manual digitising, since the markers alone are recorded, not the video
image. To get images you will need to use video tape, since the "Full
screen, Full frame rate" digitising cards are not. ( perhaps half screen at
3/4 frame rate, with a few frames missing randomly!) Controlling VCRs
accurately for digitising is why PEAK etc are so expensive.

John Yelland.

From: HowieDBPG@aol.com
Date: Mon, 9 Jan 1995 08:51:34 -0500
To: states@TAM2000.TAMU.EDU
Subject: Simple Video

Dear Becky,

I read your posting on Biomch-l. While a single camera is better than no
camera, recognize that the body is a three dimentional structure, and one
camera will give a very distorted view. Why not set up two cameras (front
and side) with a video splitter for a two-view look at things. This is far
more complete. Good luck.

Howard J. Dananberg, DPM

************** End of responses to "Simple Video System" query *************