Subscribe to our free daily newsletters
  Space Travel News  

Subscribe to our free daily newsletters

3-D mapping of entire buildings with mobile devices
by Staff Writers
Zurich, Switzerland (SPX) Jan 18, 2016

This is a 3-D model of the ETH Zurich main building. The red line indicates the path the scientists took in order to generate it. The researchers optimized this image using additional offline calculations. Image courtesy ETH Zurich and Thomas Schops. For a larger version of this image please go here.

When Thomas Schops wants to create a three-dimensional model of the ETH Zurich main building, he pulls out his tablet computer. As he completes a leisurely walk around the structure, he keeps the device's rear-facing camera pointing at the building's facade.

Bit by bit, an impressive 3D model of the edifice appears on the screen. It takes Schops, a doctoral student at the Institute for Visual Computing, just 10 minutes to digitise a historical structure such as the main building.

He developed the software running on the device in cooperation with his colleagues from the group led by Marc Pollefeys, Professor of Informatics. Development was carried out as part of Google's Project Tango, in which the internet company is collaborating with 40 universities and companies. ETH Zurich is one of them.

Pixel comparison
The ETH scientists' method works by purely optical means. It is based on comparing multiple images, which are taken on the tablet by a camera with a fisheye lens, and uses the principle of triangulation in a manner similar to that applied in geodetic surveying.

Or, to put it simply: the software analyses two images of a building's facade that were taken from different positions. For each piece of image information, each pixel in an image, it searches for the corresponding element in the other.

From these two points and from the camera's known position and viewing angle, the software can determine how far each picture element is from the device and can use this information to generate a 3D model of the object.

Long gone are the days when the models were restricted to the outlines of buildings and basic features such as window openings and doorways. Instead, they now even show architectural details such as the arrangement of bricks in a stone facade.

The new software offers some key advantages over existing methods. One advantage is that it can be used in sunlight. "Other systems work using a measuring grid of infra-red light," explains Torsten Sattler, another postdoc in Pollefeys' group who is also participating in the project. In the infra-red method, the device projects a grid of infra-red light onto an object; this grid is invisible to the human eye. An infra-red camera captures the projected image of the grid and uses this to generate a three-dimensional map of the object.

"This technique works well indoors," says Sattler. But he goes on to say that it is poorly suited to outdoor shots in sunlight. This is because sunlight also contains infra-red components, which severely interfere with the measurements.

"Outdoors, our method has clear advantages. Conversely, infra-red technology is better suited to indoor use in rooms whose structures are less pronounced, such as rooms with uniform, empty walls."

The ETH scientists programmed the software for the latest version of the Project Tango mobile device. "These tablets are still in the development phase and are not yet intended for end users, but they have been available for purchase by interested software developers for a few months now, also in Switzerland. The first apps for them have already been developed; however, at the present moment the device is out of stock," says ETH doctoral student Schops.

A fisheye lens and rigorous quality control
Pollefeys' working group already developed a 3D scanner for smartphones two years ago. This was intended for smaller objects. The current project allows even whole buildings to be mapped for the first time, thanks to the fisheye lens and the device's high processing power. "In future, this could probably even be used to survey entire districts," says Sattler.

As the researchers have found, the mapping of large objects is plagued by calculation errors in respect of the 3D coordinates. "It isn't that easy to differentiate between correct and incorrect information," explains Sattler.

"We solved the problem by programming the software to scrupulously delete all dubious values." Real-time feedback is essential to ensuring that the 3D model does not become a patchwork. Thanks to a preview mode the user always knows for which building areas they have collected enough information and which still require scanning.

Augmented reality
This real-time feedback is possible because, thanks to its high processing power, all of the calculations are performed directly on the tablet. This also paves the way for applications in augmented reality, says Sattler. One example is a city tour in which a tourist carries a tablet as they move around a city in real life.

If they view a building 'through' their tablet, additional information about the building can be displayed instantly on the screen. Other potential applications include the modelling of buildings, the 3D mapping of archaeological excavations, and virtual-reality computer games.

Furthermore, the technology could be integrated into cars to allow them to automatically detect the edge of the road, for example, or the dimensions of a parking space. Accordingly, the current project has also utilised findings from the EU's V-Charge project for the development of self-parking cars, in which Marc Pollefeys' group was also involved.

The software now developed at ETH forms part of Google's Project Tango. "Our software is now part of Google's software database. Of course, we hope that Google will make our technology available to end users and include it as standard in the next version of the Tango tablet," says Sattler.

"Obviously, our dream is that some day every mobile device will include this function, allowing the development of apps that utilise it." A large computer manufacturer recently announced its intention to put a smartphone with the Google Tango technology platform on the market this coming summer.

Schops T, Sattler T, Hane C, Pollefeys M: 3D Modeling on the Go: Interactive 3D Reconstruction of Large-Scale Scenes on Mobile Devices. Contribution to the International Conference on 3D Vision, Lyons, 19-22 October 2015

Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.

SpaceDaily Contributor
$5 Billed Once

credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly

paypal only


Related Links
ETH Zurich
Space Technology News - Applications and Research

Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks DiggDigg RedditReddit GoogleGoogle

Previous Report
3D-Printed Ceramics Could be Used in Future Space Flights
Malibu CA (Sputnik) Jan 07, 2016
Researchers have used a 3D printer to create customized ceramic parts that are strong, lightweight and handle heat better than many metals, but that do not crack easily like some traditional ceramics. The development could open the door to a new class of ceramic-body or ceramic-engine jets, said Tobias Schaedler, senior scientist at HRL Laboratories in Malibu, California. "If you go very f ... read more

SpaceX will try to land its reusable rocket on an ocean dock

Maintaining Arianespace's launch services leadership in 2016

Arianespace starts year with record order backlog

Russian Space Forces launched 21 spacecraft in 2015

Rover Rounds Martian Dune to Get to the Other Side

Boulders on a Martian Landslide

NASA suspends March launch of InSight mission to Mars

University researchers test prototype spacesuits at Kennedy

Momentum builds for creation of 'moon villages'

Chang'e-3 landing site named "Guang Han Gong"

South Korea to launch lunar exploration in 2016, land by 2020

Death rumors of Russian lunar program 'greatly exaggerated' - Deputy PM

'X' Marks a Curious Corner on Pluto's Icy Plains

Particles 'Go with the Flow' on Pluto's Surface

Looking Back at the 'Year of Pluto'

Pluto through a Stained Glass Window

Lab discovery gives glimpse of conditions found on other planets

Nearby star hosts closest alien planet in the 'habitable zone'

ALMA reveals planetary construction sites

Monster planet is 'dancing with the stars'

Falcon 9 Succeeds in Historical First-Stage Landing - But?

Russia concludes upgraded Soyuz-2 flight tests

Russia to Deliver 20 RD-180 Engines to US for Atlas 5 Carrier Rockets

SpaceX landing is a 'feat', but not a game-changer

China plans 20 launches in 2016

China's Belt and Road Initiative catches world's imagination: Inmarsat CEO

China launches HD earth observation satellite

Chinese rover analyzes moon rocks: First new 'ground truth' in 40 years

NASA Office to Coordinate Asteroid Detection, Hazard Mitigation

Student-Built Experiment Integrated onto NASA's OSIRIS-REx Mission

Dawn imaging in close Ceres orbit

Last-chance bid to contact space robot Philae

Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News

The content herein, unless otherwise known to be public domain, are Copyright 1995-2017 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement