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Hi everybody,
I am by no means an expert on markerless motion capture, but like many
of you I am intrigued by its potential. I am enough of an "old-timer"
to have experienced several landmark steps in motion capture:
1. Going from film to video
2. 2D to 3D
3. Manual to Automatic digitizing
4. Real-time display
Of course, along the way, there have been huge improvements in
resolution, frequency, animation, and computation.
This is an exciting time in biomechanics, because we are on the verge of
the next landmark step - automated, markerless motion capture. Tom
Andriacchi, Ph.D., has been a leader in introducing this to most of us
(www.stanford.edu/~stefanoc/Markerless/Markerless.html). There are now
several others working on this too. Two that I know about are mamoca
(www.mamoca.com) and Organic Motion (www.organicmotion.com).
A few weeks ago, there were a series of postings regarding automated
markerless motion capture, particularly with technology from Organic
Motion. Below is the final posting on that series - a response from
Organic Motion. I had an opportunity to meet with Organic Motion last
week, so I thought I would share some observations here.
First, the executive team at Organic Motion seemed like good, solid
people. They explained where their company is and where they are trying
to get to. Then, we discussed briefly how their technology works.
Finally, they gave me a demonstration. The demo was a calibrated space
- perhaps 15ft x 15ft - with reflective white walls and floor. There
were about 14 small cameras around the edge of the space, each with a
ring of visible-light LEDs surrounding the lens. I walked into the
space, and instantly I saw my real-time animation on a computer monitor.
I performed some simple tasks - waving, jumping - and it tracked my
motion. They collected a few trials, and we reviewed some simple
kinematics (elbow flexion vs. time). While I could not assess the data
accuracy in this brief visit, I was impressed with the real-time, 3D,
markerless data capture. There seem to be some challenges ahead for
Organic Motion - namely, validation of the accuracy and also making the
data capture more robust for bigger, more complicated motions. However,
Organic Motion showed me that they have solved the initial hurdle of
markerless tracking, so they are clearly moving in the right direction.
- Glenn S. Fleisig, Ph.D.
Glenn S. Fleisig, Ph.D., Smith & Nephew Chair of Research
American Sports Medicine Institute
833 St. Vincent's Drive, Suite 100
Birmingham, AL 35205
(email) glennf@asmi.org
(tel) 205-918-2139
www.asmi.org
-----Original Message-----
From: Glenn Fleisig
Sent: Monday, April 21, 2008 4:14 PM
To: Glenn Fleisig
Subject: Organic Motion
-----Original Message-----
From: * Biomechanics and Movement Science listserver
[mailto:BIOMCH-L@NIC.SURFNET.NL] On Behalf Of Alex Czarowicz
Sent: Wednesday, March 19, 2008 6:38 PM
To: BIOMCH-L@NIC.SURFNET.NL
Subject: Re: [BIOMCH-L] State of the Art in Markerless Motion Tracking
This is Alex Czarowicz, VP at Organic Motion - posting the official
Organic Motion response to questions and statements about our computer
vision / markerless 3D motion tracking technology.
First we want to thank all of you who have taken the time to post your
comments. Some of these posts did include a few inaccuracies about our
technology, and we wanted to join the discussion and 'set the record
straight'.
Below we outline how BioStageTM - Organic Motion's solution for the Life
Sciences works from a technical perspective, and address the validation
process and other ongoing developments.
---------------------------------------------------
An Overview of BioStage - how it works:
BioStage breaks away from the pattern comparison approach used by all
optical marker-based systems. Instead BioStage actually 'sees' the
entire person and tracks thousands of points on each subject. BioStage
recognizes human shapes and can analyze precise activity without any
need for attached 'cheating' devices (markers). We do not have a
library of movements that helps build our tracking model; instead
BioStage tracks a person's actual full body motion in real-time.
BioStage uses 14 monochrome 2D cameras to view the subject and
incorporates three general processes to create an accurate 3D model of
the subject in real-time:
Video Sub-System
The Video Sub-System acquires lens and space calibrated video from the
cameras and delivers these synchronized streams to the reconstruction
processor.
3D Reconstruction System
The 3D Reconstruction System turns the 2D video streams into 3D point
and surface clouds by triangulating the various 2D viewpoints. In this
way the 3D Reconstruction System acts much like a 3D scanner. This
system generates massive amounts of data that resembles the human
subjects as they appear inside the scan space.
Character Fitting System
The last step involves "recognizing" the human figure in this 3D data
cloud. Here BioStage uses a complex rules based approach which maps a 3D
humanoid skeleton into the data. The output data BioStage delivers is
the X, Y and Z positions and orientation (6 DOF) of 21 segments of this
skeleton and is then loaded in real-time through a plug-in directly into
biomechanical processing software (The MotionMonitor from Innovative
Sports Training or Visual3D from C-Motion). In addition a full 3D mesh
image, complete with surface textures is provided.
Currently the Character Fitting System is specialized to recognize and
track a typical human biped.
---------------------------------------------------
Space/Backdrop:
The capture volume can range from about 4 by 4 feet, up to approx 16 by
16 feet, and is flexible in its way to be set up for different analysis
needs/tasks in a lab. The current version of BioStage includes a
reflective white cloth backdrop which makes it easier for BioStage to
process the video data. A color camera system will make BioStage more
flexible to scan subjects without the need for the reflective backdrop.
Organic Motion will implement the color camera system within the year.
Data formats:
BioStage generates data that flows real-time into both The MotionMonitor
from Innovative Sports Technology and Visual 3D from C-Motion. Organic
Motion also provides an SDK to access the motion data directly.
---------------------------------------------------
Ongoing Development & Validation:
Organic Motion is in the process of performing validations of BioStage
for the Life Science community, with the expectation to demonstrate its
tracking accuracy. We are currently involved in several validation
projects, and are seeking one or two more validation studies at this
time.
The requirements/goals of these studies are to:
a. provide a fitting system that ensures precise, repeatable, consistent
length measurements of human bones/segments.
b. deliver anthropometric measurements through a defined protocol in a
totally "non-invasive" method in real-time.
c. evaluate BioStage, its performance, and to assess its accuracy,
reliability and suitability for use in research, sports and clinical
settings.
d. perform an assessment of errors that affect temporal, kinematic, and
kinetic variables when estimated by means of the proposed markerless
system compared to the existing markerbased motion capture systems using
reflective markers currently used in motion analysis.
e. validate BioStage for biomechanical research, sports and clinical
use.
---------------------------------------------------
I will be glad to show some of the research done so far on an individual
basis with typical confidentiality rights in place.
For further questions/comments please contact me at
alex@organicmotion.com
Thank you.
Alex Czarowicz
---------------------------------------------------------------
Information about BIOMCH-L: http://www.Biomch-L.org
Archives: http://listserv.surfnet.nl/archives/Biomch-L.html
---------------------------------------------------------------
I am by no means an expert on markerless motion capture, but like many
of you I am intrigued by its potential. I am enough of an "old-timer"
to have experienced several landmark steps in motion capture:
1. Going from film to video
2. 2D to 3D
3. Manual to Automatic digitizing
4. Real-time display
Of course, along the way, there have been huge improvements in
resolution, frequency, animation, and computation.
This is an exciting time in biomechanics, because we are on the verge of
the next landmark step - automated, markerless motion capture. Tom
Andriacchi, Ph.D., has been a leader in introducing this to most of us
(www.stanford.edu/~stefanoc/Markerless/Markerless.html). There are now
several others working on this too. Two that I know about are mamoca
(www.mamoca.com) and Organic Motion (www.organicmotion.com).
A few weeks ago, there were a series of postings regarding automated
markerless motion capture, particularly with technology from Organic
Motion. Below is the final posting on that series - a response from
Organic Motion. I had an opportunity to meet with Organic Motion last
week, so I thought I would share some observations here.
First, the executive team at Organic Motion seemed like good, solid
people. They explained where their company is and where they are trying
to get to. Then, we discussed briefly how their technology works.
Finally, they gave me a demonstration. The demo was a calibrated space
- perhaps 15ft x 15ft - with reflective white walls and floor. There
were about 14 small cameras around the edge of the space, each with a
ring of visible-light LEDs surrounding the lens. I walked into the
space, and instantly I saw my real-time animation on a computer monitor.
I performed some simple tasks - waving, jumping - and it tracked my
motion. They collected a few trials, and we reviewed some simple
kinematics (elbow flexion vs. time). While I could not assess the data
accuracy in this brief visit, I was impressed with the real-time, 3D,
markerless data capture. There seem to be some challenges ahead for
Organic Motion - namely, validation of the accuracy and also making the
data capture more robust for bigger, more complicated motions. However,
Organic Motion showed me that they have solved the initial hurdle of
markerless tracking, so they are clearly moving in the right direction.
- Glenn S. Fleisig, Ph.D.
Glenn S. Fleisig, Ph.D., Smith & Nephew Chair of Research
American Sports Medicine Institute
833 St. Vincent's Drive, Suite 100
Birmingham, AL 35205
(email) glennf@asmi.org
(tel) 205-918-2139
www.asmi.org
-----Original Message-----
From: Glenn Fleisig
Sent: Monday, April 21, 2008 4:14 PM
To: Glenn Fleisig
Subject: Organic Motion
-----Original Message-----
From: * Biomechanics and Movement Science listserver
[mailto:BIOMCH-L@NIC.SURFNET.NL] On Behalf Of Alex Czarowicz
Sent: Wednesday, March 19, 2008 6:38 PM
To: BIOMCH-L@NIC.SURFNET.NL
Subject: Re: [BIOMCH-L] State of the Art in Markerless Motion Tracking
This is Alex Czarowicz, VP at Organic Motion - posting the official
Organic Motion response to questions and statements about our computer
vision / markerless 3D motion tracking technology.
First we want to thank all of you who have taken the time to post your
comments. Some of these posts did include a few inaccuracies about our
technology, and we wanted to join the discussion and 'set the record
straight'.
Below we outline how BioStageTM - Organic Motion's solution for the Life
Sciences works from a technical perspective, and address the validation
process and other ongoing developments.
---------------------------------------------------
An Overview of BioStage - how it works:
BioStage breaks away from the pattern comparison approach used by all
optical marker-based systems. Instead BioStage actually 'sees' the
entire person and tracks thousands of points on each subject. BioStage
recognizes human shapes and can analyze precise activity without any
need for attached 'cheating' devices (markers). We do not have a
library of movements that helps build our tracking model; instead
BioStage tracks a person's actual full body motion in real-time.
BioStage uses 14 monochrome 2D cameras to view the subject and
incorporates three general processes to create an accurate 3D model of
the subject in real-time:
Video Sub-System
The Video Sub-System acquires lens and space calibrated video from the
cameras and delivers these synchronized streams to the reconstruction
processor.
3D Reconstruction System
The 3D Reconstruction System turns the 2D video streams into 3D point
and surface clouds by triangulating the various 2D viewpoints. In this
way the 3D Reconstruction System acts much like a 3D scanner. This
system generates massive amounts of data that resembles the human
subjects as they appear inside the scan space.
Character Fitting System
The last step involves "recognizing" the human figure in this 3D data
cloud. Here BioStage uses a complex rules based approach which maps a 3D
humanoid skeleton into the data. The output data BioStage delivers is
the X, Y and Z positions and orientation (6 DOF) of 21 segments of this
skeleton and is then loaded in real-time through a plug-in directly into
biomechanical processing software (The MotionMonitor from Innovative
Sports Training or Visual3D from C-Motion). In addition a full 3D mesh
image, complete with surface textures is provided.
Currently the Character Fitting System is specialized to recognize and
track a typical human biped.
---------------------------------------------------
Space/Backdrop:
The capture volume can range from about 4 by 4 feet, up to approx 16 by
16 feet, and is flexible in its way to be set up for different analysis
needs/tasks in a lab. The current version of BioStage includes a
reflective white cloth backdrop which makes it easier for BioStage to
process the video data. A color camera system will make BioStage more
flexible to scan subjects without the need for the reflective backdrop.
Organic Motion will implement the color camera system within the year.
Data formats:
BioStage generates data that flows real-time into both The MotionMonitor
from Innovative Sports Technology and Visual 3D from C-Motion. Organic
Motion also provides an SDK to access the motion data directly.
---------------------------------------------------
Ongoing Development & Validation:
Organic Motion is in the process of performing validations of BioStage
for the Life Science community, with the expectation to demonstrate its
tracking accuracy. We are currently involved in several validation
projects, and are seeking one or two more validation studies at this
time.
The requirements/goals of these studies are to:
a. provide a fitting system that ensures precise, repeatable, consistent
length measurements of human bones/segments.
b. deliver anthropometric measurements through a defined protocol in a
totally "non-invasive" method in real-time.
c. evaluate BioStage, its performance, and to assess its accuracy,
reliability and suitability for use in research, sports and clinical
settings.
d. perform an assessment of errors that affect temporal, kinematic, and
kinetic variables when estimated by means of the proposed markerless
system compared to the existing markerbased motion capture systems using
reflective markers currently used in motion analysis.
e. validate BioStage for biomechanical research, sports and clinical
use.
---------------------------------------------------
I will be glad to show some of the research done so far on an individual
basis with typical confidentiality rights in place.
For further questions/comments please contact me at
alex@organicmotion.com
Thank you.
Alex Czarowicz
---------------------------------------------------------------
Information about BIOMCH-L: http://www.Biomch-L.org
Archives: http://listserv.surfnet.nl/archives/Biomch-L.html
---------------------------------------------------------------