Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Capturing movements of actors and athletes in real time with conventional video cameras

28.08.2012
Within milliseconds, and just with the help of mathematics, computing power and conventional video cameras, computer scientists at the Max-Planck-Institute for Informatics in Saarbrücken can automatically capture the movements of several people. The new approach helps not only animation specialists in Hollywood movies but also medical scientists and athletes.

In the computer graphics (CG) animated comedy “Ted,” which is running now in the cinemas, Ted is a teddy bear who came to life as the result of a childhood wish of John Bennett (Mark Wahlberg) and has refused to leave his side ever since. CG Animated characters like “Ted” have become a standard of Hollywood’s movie productions since the blockbuster “Avatar” with its blue-skinned computer-animated characters won three Oscars and brought in three billion US dollars, digital animated characters have become a standard of Hollywood’s movie productions.

While movies like “Pirates of the Caribbean” or “Ted” still combined real actors with digital counterparts, the well-known director Steven Spielberg focused entirely on virtual actors in “The Adventures of Tintin.” He used the so-called motion capture approach, which also animated Ted. Motion capture means that an actor wears a suit with special markers attached. These reflect infrared light sent and received by a camera system installed in a studio. In this way, the system captures the movements of the actor. Specialists use this as input to transfer exactly the same movements to the virtual character.

“The real actors dislike wearing these suits, as they constrain their movements,” explains Christian Theobalt, professor of computer science at Saarland University and head of the research group “Graphics, Vision & Video” at the Max-Planck-Institute for Informatics (MPI). Theobalt points out that this has not changed since animating “Gollum” in the trilogy “Lord of the Rings.” Hence, together with his MPI-colleagues Nils Hasler, Carsten Stoll and Jürgen Gall of the Swiss Federal Institute of Technology Zurich, Theobalt developed a new approach that both works without markers and captures motions in realtime. “The part which is scientifically new is the way in which we represent and compute the filmed scene. It enables new speed in capturing and visualizing the movements with normal video cameras,” Theobalt explains.

Implemented, it looks like this: The video cameras record a researcher turning cartwheels. The computer gets the camera footage as input and computes the skeleton motion of the actor so quickly that you cannot perceive any delay between the movement and its overlay, a red skeleton. According to Theobalt, the new computing approach also works if the movements of several persons have to be captured, or if they are obscured by objects in the studio and against a noisy background.

“Therefore we are convinced that our approach even enables motion capture outdoors, for example in the Olympic stadium,” Theobalt points out. Athletes could use it to run faster, to jump higher or to throw the spear farther. Spectators in the stadium or in front of the TV could use the technology to tell the difference between first and second place. Besides entertainment, medical science could also benefit from the new approach, for example by helping doctors to check healing after operations on joints.

In the next months his MPI colleagues Nils Hasler and Carsten Stoll will found a company to transform the software prototype into a real product. “They’ve already had some meetings with representatives sent by companies in Hollywood,” Theobalt says.

Technical background

The new approach requires technology which is quite cheap. You need no special cameras, but their recording has to be synchronized. According to the MPI researcher, five cameras are enough that the approach works. But they used twelve cameras for the published results. The way they present the scene to the computer and let it compute makes the difference. Hence, they built a three-dimensional model of the actor whose motions should be captured. The result is a motion skeleton with 58 joints. They model the proportions of the body as so-called sums of three dimensional Gaussians, whose visualisation looks like a ball. The radius of the ball varies according to the dimensions of the real person. The resulting three-dimensional model resembles the mascot of a famous tire manufacturer.

The images of the video cameras are presented as two-dimensional Gaussians that cover image blobs that are consistent in color.

To capture the person’s movement, the software continuously computes the best way that the 2D and 3D Gaussians can overlay each other while fitting accurately. The Saarbrücken computer scientists are able to compute these model-to-image similarities in a very efficient way. Therefore, they can capture the filmed motion and visualize it in real-time. All they need is just a few cameras, some computing power and mathematics.

Computer Science on the Saarland University Campus

Apart from the Saarland University chair in computer science and Max Planck Institute for Informatics, there are several other research institutes exploring new information technologies and their impact on society. The German Research Center for Artificial Intelligence (DFKI), the Max Planck Institute for Software Systems, the Center for Bioinformatics, the Intel Visual Computing Institute, Center for IT-Security, Privacy and Accountability, and the Cluster of Excellence on “Multimodal Computing and Interaction” can also be found there.

More Information:
Carsten Stoll, Nils Hasler, Juergen Gall, Hans-Peter Seidel, Christian Theobalt,
Fast Articulated Motion Tracking using a Sums of Gaussians Body Model
http://www.mpi-inf.mpg.de/~theobalt/sog.pdf

Video online
http://www.mpi-inf.mpg.de/~theobalt/sog.mp4

For further questions please contact:
Prof. Dr. Christian Theobalt
Campus E 1.4
66123 Saarbrücken
E-Mail: theobalt@mpii.de
Tel.: +49 681 9325-428

Gordon Bolduan
Science Communication
Cluster of Excellence “Multimodal Computing and Interaction”
E-Mail: bolduan@mmci.uni-saarland.de
Tel.: +49 681 302-70741

| Universität des Saarlandes
Further information:
http://www.mpi-inf.mpg.de/~theobalt/sog.pdf
http://www.mpi-inf.mpg.de/~theobalt/sog.mp4

More articles from Information Technology:

nachricht Construction of practical quantum computers radically simplified
05.12.2016 | University of Sussex

nachricht UT professor develops algorithm to improve online mapping of disaster areas
29.11.2016 | University of Tennessee at Knoxville

All articles from Information Technology >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Closing the carbon loop

08.12.2016 | Life Sciences

Applicability of dynamic facilitation theory to binary hard disk systems

08.12.2016 | Physics and Astronomy

Scientists track chemical and structural evolution of catalytic nanoparticles in 3-D

08.12.2016 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>