Faculty

A new 4D camera designed by Professor Gordon Wetzstein and postdoc Dr. Donald Dansereau captures light field information over a 138° field of view.

The difference between looking through a normal camera and the new design is like the difference between looking through a peephole and a window, the scientists said.

"A 2D photo is like a peephole because you can't move your head around to gain more information about depth, translucency or light scattering," Dansereau said. "Looking through a window, you can move and, as a result, identify features like shape, transparency and shininess."

That additional information comes from a type of photography called light field photography, first described in 1996 by EE Professors Marc Levoy and Pat Hanrahan. Light field photography captures the same image as a conventional 2D camera plus information about the direction and distance of the light hitting the lens, creating what's known as a 4D image. A well-known feature of light field photography is that it allows users to refocus images after they are taken because the images include information about the light position and direction. Robots might use this to see through rain and other things that could obscure their vision.

The extremely wide field of view, which encompasses nearly a third of the circle around the camera, comes from a specially designed spherical lens. However, this lens also produced a significant hurdle: how to translate a spherical image onto a flat sensor. Previous approaches to solving this problem had been heavy and error prone, but combining the optics and fabrication expertise of UCSD and the signal processing and algorithmic expertise of Wetzstein's lab resulted in a digital solution to this problem that not only leads to the creation of these extra-wide images but enhances them.

This camera system's wide field of view, detailed depth information and potential compact size are all desirable features for imaging systems incorporated in wearables, robotics, autonomous vehicles and augmented and virtual reality.

"Many research groups are looking at what we can do with light fields but no one has great cameras. We have off-the-shelf cameras that are designed for consumer photography," said Dansereau. "This is the first example I know of a light field camera built specifically for robotics and augmented reality. I'm stoked to put it into peoples' hands and to see what they can do with it."

Two 138° light field panoramas and a depth estimate of the second panorama. (Image credit: Stanford Computational Imaging Lab and Photonic Systems Integration Laboratory at UC San Diego)

Read more at Professor Wetztein's research site, Stanford Computational Imaging Lab.

Excerpted from Stanford News, "New camera designed by Stanford researchers could improve robot vision and virtual reality," July 21, 2017.

Professor David Tse has been appointed to the Thomas Kailath and Guanghan Xu Professorship in the School of Engineering. This professorship was established with an endowed gift from Guanghan Xu, a Stanford alum who earned his PhD in EE. Guanghan established this professorship to honor his advisor, Thomas Kailath, the Hitachi America Professor in the School of Engineering, Emeritus. The Thomas Kailath and Guanghan Xu Professorship carries preference for faculty whose academic focus is in the broad field of signal processing and its applications.

David has been a member of the Stanford faculty since 2014. His research focuses on information theory and its applications in various fields, including wireless communication, energy, and computational biology. David serves at the Stanford Information Systems Laboratory, and is the inventor of the proportional fair scheduling algorithm used in all third- and fourth-generation cellular systems. He also co-authored with Pramod Viswanath the text Fundamentals of Wireless Communication, which has been used in over 60 institutions around the world.

Prior to joining the Stanford faculty, David served in the department of electrical engineering and computer sciences at the University of California, Berkeley from 1995 to 2014, and was a member of the technical staff at AT&T Bell Laboratories from 1994 to 1995.

A fellow of the Institute of Electrical and Electronics Engineers (IEEE), David has received the IEEE Communications Society and Information Theory Society Joint Paper Award on three occasions, and he has served on the IEEE Information Theory Society's Board of Governors twice. He is a recipient of the National Science Foundation CAREER Award and the Canadian Natural Sciences and Engineering Research Council 1967 Graduate Fellowship. David has been honored with the Outstanding Teaching Award from the department of electrical engineering and computer sciences at the University of California, Berkeley, and he is a recipient of the American Society for Engineering Education's Frederick Emmons Terman Award, the National Academy of Engineering's Gilbreth Lectureship, and the IEEE Information Theory Society Claude E. Shannon Award.

David received a bachelor's degree in systems design engineering from the University of Waterloo in 1989, and MS and PhD degrees in electrical engineering from the Massachusetts Institute of Technology in 1992 and 1994, respectively.

David's contributions to the field of information theory and its applications make him a deserving candidate for the Thomas Kailath and Guanghan Xu Professorship in the School of Engineering.

Please join us in congratulating David on this achievement.

Related News:

2017 Claude E. Shannon Award, July 2016

David's EE Spotlight 

If electric cars could recharge while driving down a highway, it would virtually eliminate concerns about their range and lower their cost, perhaps making electricity the standard fuel for vehicles.

Now Stanford University scientists have overcome a major hurdle to such a future by wirelessly transmitting electricity to a nearby moving object. Their results are published in the June 15 edition of Nature.

"In addition to advancing the wireless charging of vehicles and personal devices like cellphones, our new technology may untether robotics in manufacturing, which also are on the move," said Shanhui Fan, a professor of electrical engineering and senior author of the study. "We still need to significantly increase the amount of electricity being transferred to charge electric cars, but we may not need to push the distance too much more."

The group built on existing technology developed in 2007 at MIT for transmitting electricity wirelessly over a distance of a few feet to a stationary object. In the new work, the team transmitted electricity wirelessly to a moving LED lightbulb. That demonstration only involved a 1-milliwatt charge, whereas electric cars often require tens of kilowatts to operate. The team is now working on greatly increasing the amount of electricity that can be transferred, and tweaking the system to extend the transfer distance and improve efficiency.

"We can rethink how to deliver electricity not only to our cars, but to smaller devices on or in our bodies," Fan said. "For anything that could benefit from dynamic, wireless charging, this is potentially very important."

The study was also co-authored by former Stanford research associate Xiaofang Yu. Part of the work was supported by the TomKat Center for Sustainable Energy at Stanford.

Excerpted from Stanford News, "Wireless charging of moving electric vehicles overcomes major hurdle in new Stanford research," June 14, 2017.

By Julie Chang, PhD candidate

The seventh annual IEEE International Conference on Computational Photography (ICCP) was hosted at Stanford University on May 12-14, 2017. Over 200 students, post-docs, professors, and entrepreneurs from around the world came together to discuss their research in this area. Professor Gordon Wetzstein from Stanford served as program chair alongside Laura Waller from UC Berkeley and Clem Karl from Boston University.

Wetzstein leads the Computational Imaging group at Stanford, which works on advancing the capabilities of camera and display technology through interdisciplinary research in applied math, optics, human perception, computing, and electronics. Active areas of research include virtual reality displays, advanced imaging systems, and optimization-based image processing. Wetzstein also teaches the popular Virtual Reality course (EE 267) as well as Computational Imaging and Displays (EE 367) and Digital Image Processing (EE 368). Several members of Wetzstein's lab presented their work at the conference. Isaac Kauvar (co-advised by Karl Deisseroth) and Julie Chang's paper on "Aperture interference and the volumetric resolution of light field fluorescence microscopy" was accepted for a talk. Posters and demos from Wetzstein's group included Nitish Padmanaban's provocatively titled project on "Making Virtual Reality Better Than Reality," Robert Konrad's spinning VR camera nicknamed "Vortex", and Felix Heide's domain-specific language "ProxImaL" for efficient image optimization.

ICCP 2017 was comprised of nine presentation sessions each with several accepted and invited talks organized around topics such as time-of-flight and computational illumination, image processing and optimization, computational microscopy, and turbulence and coherence. There was a mix of hardware and software projects for a wide variety of applications, ranging from gigapixel videos to seeing in the dark to photographic stenography. One keynote speaker was scheduled for each day. In Friday's keynote, Professor Karl Deisseroth (Stanford) discussed the importance of optical tools, namely optogenetics and advanced fluorescence microscopy, to help elucidate the inner working of the brain. The second keynote was given by Paul Debevec (USC/Google), who showed some of his team's work in computational relighting, both in Hollywood to make movies such as 'Gravity' possible, and in the White House to construct Barack Obama's presidential bust. The final keynote speaker was Professor Sabine Susstrunk (EPFL), who spoke on the non-depth-measurement uses of near-infrared imaging in computational photography.

The conference this year also included an industry panel on computational photography start-ups comprised of seasoned experts Rajiv Laroia of Light, Ren Ng of Lytro, Jingyi Yu, and Kartik Venkataraman of Pelican Imaging. Kari Pulli of Meta chaired a lively discussion covering the risks and thrills of startups, comparison with working at large companies, and the future of the computational photography industry.

The best paper award was received by Christian Reinbacher, Gottfried Munda, and Thomas Pock for their work on real-time panoramic tracking for event cameras. By popular vote, the best poster award was presented to Katie Bouman et al., for their work on "Turning Corners into Cameras," a method of seeing around corners by looking at the shadows produced at a wall corner, and the best demo award to Grace Kuo et al, for "DiffuserCam," which allows for imaging with a diffuser in place of a lens.

Professor Stephen Boyd was awarded an honorary doctorate from the Institute of Statistics, Biostatistics and Actuarial Sciences of the Catholic University of Louvain for his achievements in the field of data sciences.

The awards ceremony was held earlier in May at the Universite Catholique de Louvain. Stephen participated in a roundtable discussion and presented on Convex Optimization.

Please join us in congratulating Stephen for this well deserved recognition of his profound contributions.

Professor emeritus Thomas Kailath received an Honorary Degree from National Technical University of Athens.

In a letter from Nectarios Koziris, Professor and Dean of the School, the announcement reads "[...] it is a great honor to announce to you that the School's assembly has unanimously decided to confer on you an Honorary Doctorate Degree. Please consider that as our School's token of appreciation for your lifetime accomplishments that benefited science and added a valuable arrow in the quiver of the people who decided in their lives to attack the big problems."

Congratulations to Tom on his many important achievements!

"Quantum computing is ideal for studying biological systems, doing cryptography or data mining – in fact, solving any problem with many variables," states Professor Jelena Vuckovic. "When people talk about finding a needle in a haystack, that's where quantum computing comes in."

 In her own studies of nearly 20 years,  Vuckovic has focused on one aspect of the challenge: creating new types of quantum computer chips that would become the building blocks of future systems.

"To fully realize the promise of quantum computing we will have to develop technologies that can operate in normal environments," she said. "The materials we are exploring bring us closer toward finding tomorrow's quantum processor."

The challenge for Vuckovic's team is developing materials that can trap a single, isolated electron. Working with collaborators worldwide, they have recently tested three different approaches to the problem, one of which can operate at room temperature – a critical step if quantum computing is going to become a practical tool.

In all three cases the group started with semiconductor crystals, material with a regular atomic lattice like the girders of a skyscraper. By slightly altering this lattice, they sought to create a structure in which the atomic forces exerted by the material could confine a spinning electron.

"We are trying to develop the basic working unit of a quantum chip, the equivalent of the transistor on a silicon chip," states Vuckovic. "We don't know yet which approach is best, so we continue to experiment."

Excerpted from the Stanford News, "Stanford team brings quantum computing closer to reality with new materials".

Photo credit: Amanda Law

At the invitation of the Optical Society of America (OSA), professor Jelena Vuckovic (also a Fellow of the OSA since 2015) hosted a Reddit Science Ask Me Anything (AMA) session. The session was primarily directed to students, but the format allows anyone to post a question.

The Reddit format introduced Jelena and her research in the areas of nanophotonics, quantum optics, nonlinear optics, quantum information technologies and optoelectronics. During the afternoon session, Jelena provided answers to more than 25 Reddit users who posted questions. The discussion thread will remain on Reddit, and can be viewed at: www.reddit.com/r/science/comments/5ssbx2/science_ama_series_im_dr_jelena_vuckovic/

AMAs (short for 'Ask Me Anything') were created by the Reddit community as an opportunity for interesting individuals to field questions about anything – and everything! AMAs hosted on Reddit have succeeded in becoming an exciting platform for people to have direct discussions and gain insight into the lives of unique individuals, with some of the historically most-popular AMAs including those from President Barack Obama, Sir David Attenborough, Bill Gates, Elon Musk and many others.

In an effort to bring science education to the public, the Reddit Science community (known as /r/Science) has created an independent, science-focused AMA Series – the Science AMA Series. Their goal is to encourage discussion and facilitate outreach while helping to bridge the gap between practicing scientists and the general public. The series is open to any practicing research scientist, or group of scientists, that wants to have a candid conversation with the large and diverse Reddit Science community.

The paper, "Packet switching in radio channels: Part I – carrier sense multiple-access modes and their throughput-delay characteristics" was coauthored by professor Fouad Tobagi and Len Kleinrock in 1975.

The award citation reads, "A pioneering contribution to the early days of wireless packet networks that is on the reading list of any student interested in the foundation of media access control in packet radio networks. This paper makes a fundamental contribution to the development of carrier sense multiple access (CSMA) that underpins the wireless edge today."

The SIGMOBILE Test-of-Time awards recognize papers that have had a sustained and significant impact in the SIGMOBILE community over at least a decade. The award recognizes that a paper's influence is often not fully apparent at the time of publication, and it can be best judged with the perspective of time.

The ToT awards were presented at the 22nd Annual International Conference on Mobile Computing and Networking in New York. A half-day session was dedicated to this award comprising presentations and a "Future Mobile Panel" with the several ToT authors.

Professor Tobagi works on network control mechanisms for handling multimedia traffic (voice, video and TCP- based applications) and on the performance assessment of networked multimedia applications using user-perceived quality measures. He also investigates the design of wireless networks, including QoS-based media access control and network resource management, as well as network architectures and infrastructures for the support of mobile users, all meeting the requirements of multimedia traffic. He also investigates the design of metropolitan and wide area networks combining optical and electronic networking technologies, including topological design, capacity provisioning, and adaptive routing.

Congratulations to Fouad on this well-deserved recognition.

Andrea Goldsmith has been elected to the American Academy of Arts and Sciences, one of the country's oldest and most prestigious honorary learned societies. The 2017 class includes some of the world's most accomplished scholars, scientists, writers, artists and civic, business and philanthropic leaders.

"It is an honor to welcome this new class of exceptional women and men as part of our distinguished membership," said Don Randel, Chair of the Academy's Board of Directors. "Their talents and expertise will enrich the life of the Academy and strengthen our capacity to spread knowledge and understanding in service to the nation."

Members of the 2017 class include winners of the Pulitzer Prize and the Wolf Prize; MacArthur Fellows; Fields Medalists; Presidential Medal of Freedom and National Medal of Arts recipients; and Academy Award, Grammy Award, Emmy Award, and Tony Award winners.

"In a tradition reaching back to the earliest days of our nation, the honor of election to the American Academy is also a call to service," said Academy President Jonathan F. Fanton. "Through our projects, publications, and events, the Academy provides members with opportunities to make common cause and produce the useful knowledge for which the Academy's 1780 charter calls."

The new class will be inducted at a ceremony on October 7, 2017, in Cambridge, Massachusetts.

Founded in 1780, the American Academy of Arts and Sciences is one of the country's oldest learned societies and independent policy research centers, convening leaders from the academic, business, and government sectors to respond to the challenges facing—and opportunities available to—the nation and the world. Members contribute to Academy publications and studies in science, engineering, and technology policy; global security and international affairs; the humanities, arts, and education; and American institutions and the public good.

Please join us in congratulating Andrea for this very well deserved recognition of her work!

American Academy of Arts & Sciences Press Release