[Home]   [Full version]  

From 2-D pictures to 3 dimensions

Mar 03 ,Technology



Full size image
Your pictures of the Grand Canyon, Times Square or other destinations may be pretty good, but wouldn’t it be nice to show them off in three dimensions?

An award-winning 3D reconstruction algorithm designed by a team of computer science researchers from UC San Diego brings this dream within the grasp of reality.

This research gets at the heart of “autocalibration,” a well-studied, fundamental problem in computer vision. Autocalibration aims to recover the three dimensional structure of a scene using only its images, acquired from cameras whose internal settings and spatial orientations are unknown.

Autocalibraton is part of a larger 3D image reconstruction challenge that has caught the attention of Google, Microsoft and others.

Manmohan Chandraker, a fifth-year PhD student in the Department of Computer Science and Engineering at UCSD’s Jacobs School of Engineering led the work. He, Sameer Agarwal – a computer science UCSD alumnus now at the University of Washington, and their respective Ph.D. advisors, David Kriegman and Serge Belongie presented their research at the International Conference on Computer Vision (ICCV), held in Rio de Janeiro, Brazil in October 2007. ICCV is the premier conference in the field of computer vision. For this work, Chandraker took home one of three honorable mentions for ICCV’s prestigious David Marr prize.

This technology could be put to use in a wide variety of applications. For example, someone selling shoes online could take pictures of their shoes and create 3D reconstructions of their inventory. Such reconstructions would provide more information about what the shoes actually look like than images or video footage can.

The algorithm could also be used to automatically align security camera networks used in casinos and airports. Coupled with existing technology for immersive media, the algorithm could be used to create augmented-reality walkthroughs of cities, supermarkets or any other places of interest.

In the ICCV paper, the UCSD computer scientists propose the first practically scalable algorithm for 3D reconstruction which provides “a theoretical certificate of optimality.” In other words, the technique computes the best possible 3D reconstruction obtainable from the input data and does not slow down drastically for a large number of photographs.

“Our algorithm is guaranteed to provide the best 3D reconstruction,” said Chandraker. “It is very much a practical algorithm. In fact, the significance of the paper lies in our approaches for designing a theoretically correct algorithm that also works well in practice. Our approach utilizes modern convex optimization techniques to globally minimize the involved cost functions in a branch and bound framework,” explained Chandraker.

The paper, titled “Globally Optimal Affine and Metric Upgrades in Stratified Autocalibration” is available at http://vision.ucsd.edu/kriegman-grp/papers/iccv07a.pdf . MATLAB prototype code for the implementation will be available online when it is ready.

Source: University of California - San Diego

Related stories:

Scientists take the sharpest image ever made with light
(PhysOrg.com) -- A team of scientists from the Technische Universität Dresden (Germany) and the ESRF in Grenoble (France) has produced the image of an object at the highest resolution ever achieved with X-ray light. A 100-nanometre gold particle fixed on a substrate was reconstructed with 5 nanometre resolution. Contrary to other techniques, X-ray imaging works also in real-life environments like chemical processing or in the presence of high magnetic fields. The team reports its findings in the newest issue of Phys. Rev. Lett. dated 5 September 2008 (published online 29 August 2008).
Biogas production is all in the mixing
Engineers at Washington University in St. Louis, using an impressive array of imaging and tracking technologies, have determined the importance of mixing in anaerobic digesters for bioenergy production and animal and farm waste treatment. Anaerobic digesters employ reactors that use bacteria to break down organic matter in the absence of oxygen.
Stanford site advances science of turning 2-D images into 3-D models
An artist might spend weeks fretting over questions of depth, scale and perspective in a landscape painting, but once it is done, what's left is a two-dimensional image with a fixed point of view. But the Make3d algorithm, developed by Stanford computer scientists, can take any two-dimensional image and create a three-dimensional "fly around" model of its content, giving viewers access to the scene's depth and a range of points of view.
Software, evolution and micro-inversions -- improving the building of phylogenetic trees
Biologists will be able to reconstruct the process of evolution, determine relationships between species and build phylogenetic trees with greater accuracy thanks to a new method for identifying “microinversions,” which are extremely short strings of inverted nucleotides.
This new work from researchers at UC San Diego and Brown University will appear in the online version of PNAS on December 18, 2006.
Better track leads to new particles
In particle accelerators new particles often arise as a result of collisions between elementary particles. However the track left by these particles is often difficult to trace. Dutch researcher Thijs Cornelissen developed an algorithm to reconstruct the particle tracks and that is being used in a European research institute for particle physics. His method provides greater insights into the origin of particles that arise as a result of collisions.
Mathematicians Solve the 'Cocktail Party Problem'
Officials at the CIA and scientists around the world have pondered the "cocktail party problem" for decades. How could they separate one sound - perhaps a voice - from a group of other recorded sounds, perhaps a multitude of voices at a cocktail party? Now, two researchers at the University of Missouri-Columbia have found a mathematical solution to this problem.
Picking particles faster than one at a time
Computer scientists and biologists at the Department of Energy's Lawrence Berkeley National Laboratory have developed software that can select tens of thousands of high-quality images of biological molecules from electron microgaphs, rapidly and automatically, with accuracy approaching that of experienced human analysts.
Researchers develop new self-training gene prediction program for fungi
Researchers at the Georgia Institute of Technology have developed a computer program that trains itself to predict genes in the DNA sequences of fungi.

News discussion:

Technology news

[Home]   [Full version]