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 Information integration and artificial intelligence for better diagnosis and therapy decisions
24.05.2017 | Fraunhofer MEVIS - Institut für Bildgestützte Medizin

nachricht World's thinnest hologram paves path to new 3-D world
18.05.2017 | RMIT University

All articles from Information Technology >>>

The most recent press releases about innovation >>>

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

Im Focus: Can the immune system be boosted against Staphylococcus aureus by delivery of messenger RNA?

Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.

Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

How herpesviruses win the footrace against the immune system

26.05.2017 | Life Sciences

Water forms 'spine of hydration' around DNA, group finds

26.05.2017 | Life Sciences

First Juno science results supported by University of Leicester's Jupiter 'forecast'

26.05.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>