Tech Talk iconTech Talk

SIGGRAPH Asia: 3D models from photographs

Two presentations in a session on urban modeling here delved into generating three-dimensional models of buildings and streets from casual sets of photographs.

Generating 3D models from 2D images isnâ''t a particularly advanced field, so these two new approaches definitely caught my eye. The state of the art requires a fair amount of user guidance to help the image-processing algorithms differentiate between a target object and visual clutter, such as trees, passing cars, and street signs. There's plenty of room for improvement in accuracy and detail, and users can always hope for a faster process and simpler interfaces.

Currently, the most accessible method of 3D modeling from photographs is probably Google SketchUpâ''s Photo Match feature. SketchUp is a modeling application that Google bought and then released almost three years ago. In Photo Match, a user imports an image and then traces over the lines of a buildingâ''the more sets of parallel lines, the better. Not surprisingly, those lines carry information about the perspective of the camera when the image was shot. The program uses that data to extrapolate the overall shape of the building. Once the rough outline is in place, the software can extract patterns from the photo to overlay texture detail. Voila, a quick-and-dirty 3D building. For better results, you can do the whole thing over again with another photo of the hidden sides.

The two methods presented here apply new methods to processing a collection of photos of a target scene.

One technique came out of a partnership between the University of North Carolinaâ''Chapel Hill, UC-Berkeley, ETH Zurich, and Microsoft Research. This approach starts with a jumble of images of a building or city. Preliminary image analysis identifies the imageâ''s vanishing points, similar to Photo Match. A user traces the rectangular outlines of the primary building walls, a geometric model is generated, and the textures from the original photograph are applied. My sense is that the main advances here over Photo Match are in the intelligent way that the photos are processed together to create a preliminary model, and in a simpler user experience. In ten to fifteen minutes, you can easily generate a model of a building from 8 or 9 photos. Give it an hour and 120 photographs and itâ''ll generate a fairly accurate model of a city. Of course, itâ''s a trade-off between the quantity of data needed to start off and the fidelity of the model.

The second method came from researchers at the Hong Kong University of Science and Technology and the National University of Singapore. It focused on facades rather than complete buildings. To start, a photographer drives down a street and takes successive shots of a continuous façade (of a shopping street, for example). Those photos are automatically lined up, pattern-matched, and analyzed at a fairly deep level to generate a large mapping of points that capture the color, texture, and depth of various parts of a facade. The images are broken down into sections, analyzed for things such as embedded symmetries (to identify evenly spaced features that ought to be identical), then merged back together to speed up the rendering. A user helps the program identify the façadeâ''s salient features (this part of the talk was left unclear), and voila, an extremely detailed rendering of a street face pops up.

Neither approach is complete, but things move fast in the graphics world. It could be a matter of months before something along these lines gets incorporated into existing 3D modeling tools.

SIGGRAPH Asia: Virtual tigers, real engineers

If you're set on building a virtual reality installation, you've basically got a few paths to choose from:

- reflect ponderously on the shortcomings of perception.

- juxtapose unfamiliar environments for the sake of being weird.

- claim it's all for the greater good of education, expanding the mind, or shrinking physical distances.

In other words, there's a reason that VR has struggled to find its place. But that doesn't mean my cynical heart didn't thaw at the sight of this virtual take on historical fiction, by students from Nanyang Technological University, in Singapore. It explores local lore about the last wild tiger in Singapore, which was supposedly shot at the famous Raffles Hotel. (In addition to giving the world one dead tiger, the hotel also reputedly invented the Singapore Sling.)

In this installation, a user wears a headset that superimposes a video projection on a real-world set. As the individual turns his or her head, the head-mounted display exposes new facets of the scene. It's a bit hard to follow for observers not wearing the headset, but the swift changes in perspective do make for a convincing visual experience for the user.

SIGGRAPH Asia: Advice to a budding graphics guru

The first SIGGRAPH held in Asia is under way this week in Singapore, and the usual arts and entertainment crowd is parading its wares at this epic graphics technology conference. Iâ''ve struggled to resist asking exhibitors that awful wet-blanket question, â''soâ'¿ what could this possibly be useful for?â'' because of course that isnâ''t always the point. Nonetheless, I canâ''t help wondering how many versions of, say, gesture-based gaming the world could possibly need.

So it was with some satisfaction that I listened to Don Greenberg, an early graphics pioneer, question that same narrow focus on entertainment in his keynote speech here. Greenberg, the director of Cornellâ''s computer graphics program, noted that while cutting-edge computer graphics research into animation and gaming is unquestionably valuable, the uses for those talents are also obvious in fields such as medical imaging, computer-aided design, and architectural modeling, to name a few. And with the ubiquity of display devices and cheap processing power, that algorithmic and software expertise ought to find a broader audience.

Greenberg cited a project he recently worked on with his son, a surgeon at the Cleveland Clinic. They came up with mathematical models to design a personalized intravascular stent, which is used to prop open vessels to allow for healthy blood flow through a constricted path. Applying graphics techniques to analyze CT scans, he was able to design within quarter-millimeter accuracy the size and shape of a personalized stent to fit a patientâ''s blood vessel. And that was done with precious little medical knowledge, so the barriers are low.

At a later panel with several LucasFilm artists, another point hit home. The reality is that while the gaming and special-effects industries are large, companies such as LucasFilm, Pixar, and Dreamworks predominantly hire artists and animators, with software engineers making up a much smaller percentage of the workforce. But of course itâ''s the engineers who are bringing new techniques to revolutionize the visual experience. The enthusiasm for graphics among computer scientists just isnâ''t matched, head for head, in the job market. Greenberg compared the artists-engineers discrepancy to an hourglass â'' the sand particles closest to the neck are moving and changing position the fastest, but they are also the fewest.

Graphics specialists are among the most artistic engineers out there. They, more than others, have whittled down that stereotypical left-brain, right-brain split to produce viscerally satisfying experiences. And they, more than others, may also be better-equipped to hop across disciplinary barriers and share their talents for the benefit of mankind.

Nanotechnology and the Glazed Over Look You Get When Describing It

Long ago I lost count on the times I have tried to explain what nanotechnology is to friends and family. Despite the large number of times I have engaged in this fruitless enterprise, the reaction process is striking similar in most cases.

First you get earnest interestâ''they are your friends and family after all. Then you begin to see the confusion start to set in, which is usually accompanied by what seems to you a very strange question. After trying to answer the question, the confusion has become so great that they have completely lost interest and they are staring off into the ether dreaming of when you are going to shut up.

After listening to Professor Tony Ryan of Sheffield University conduct man-on-the-street interviews for the BBCâ''s Street Science radio program, I couldnâ''t help but think about the times I have engaged in the joyless job of describing nanotech.

Against insurmountable odds Professor Ryan sallies forth again and again to meet his enemyâ'¿umh I mean public. Unbowed after getting responses from university professors who confess all they know about nanotechnology is â''grey gooâ'', he tries to get his interviewees to grasp some basic concept about nanotechnology.

Itâ''s hard to know if he really succeeds with anyone. But after a lengthy and somewhat complicated explanation to a couple of how nanotechnology is involved in 2-in-1 shampoo, which initially elicits the typical â''Isnâ''t that interestingâ'' response, the man asks something like â''Wouldnâ''t it make more sense to use this technology for treating diseases rather than making shampoo?â''

If I were Professor Ryan, I would walk away with the feeling that this one question alone made it all worth it.

Computer Pioneers Celebrating Anniversary of Interactive Computing Urge Industry to Go Back to the Future


Yesterday, the pioneers of the computing revolution gathered together at Stanford Universityâ''s Memorial Auditorium to celebrate the birthday of interactive computing. On Dec 9th, 1968 Doug Engelbart and his team from the Augmentation Research Center at the Stanford Research Institute (SRI) gave a 90-minute demo that rocked a world used to punch cards and teletype machines. The demonstration included hypertext linking, multiple windows, real-time text editing, shared screen teleconferencing, and the computer mouse. Perhaps even more revolutionary, it showed that a computer could help people with more varied tasks then mathematical computationâ''like managing a shopping list (something I do on my computer to this day).

After watching clips of the demo, the crowd at the anniversary celebration gave Engelbart, sitting in the audience, a long and enthusiastic standing ovation. Then a panel of folks that were there at the beginning talked about that break through demonstration and the evolution of computing since.

The mood was one of nostalgia; during breaks, black and white slides of longhaired computer researchers flashed on a screen, accompanied by the 1968 hit â''Those Were the Daysâ''.

There was a lot of talk of what weâ''ve gainedâ''better search and universal access make computing a far more powerful proposition than it was back in the 60s. But there was also talk of what weâ''ve lost. Said Andries van Dam, a professor of computer science at Brown University who attended the 1968 demonstration, â''This vision hasnâ''t been realized. We can do a lot of the individual things that were done in [Engelbartâ''s] system better, but they donâ''t play nice together. They had everything interoperable in this superrich environment. Weâ''ve lost that.â''

â''Iâ''m looking for a reintegration of the various components so we can go back to the future,â'' van Dam said to a burst of applause, pointing out, in particular, the ease of multimedia teleconferencing on the 1968 system. But, he mused, â''I donâ''t see how we are going to get there.â''

Boston Power's Sonata Batteries Coming to H-P Laptops


Back last fall I saw a prototype of a safe, long-lasting, environmentally friendly lithium-ion battery, built by Westborough, Mass., start-up Boston Power. Company founder Christina Lampe-Onnerud, who IEEE Spectrum tagged in its March issue as â''The Lady and the Li-On,â'' called me this week with happy news. Hewlett-Packard was to announce today that it will be using Boston Powerâ''s Sonata lithium-ion cells to power its HP Enviro Series notebook batteries.

These batteries will come with a three-year warranty, the longest battery warranty offered to date. Seems that H-P is convinced that the Sonata cells will indeed hold up longer than traditional designs, as Lampe-Onnerud told Spectrum last year. However, H-Pâ''s promotion for these batteries will be playing up the green angle more than the performance.

Lampe-Onnerud is thrilled. â''Our company is only three years old,â'' she says, and â''H-P is number one in the laptop marketplace. Itâ''s such a lovely way for us to end 2008.â''

H-P will be shipping the new battery packs early next year, as replacement batteries only, not built into new laptops. â''That was the way to get into consumersâ'' hands as soon as possible,â'' Lampe-Onnerud says.

For Boston-Power, this may work out just fine. Youâ''d have to think that in the current economy, people are going to be hanging onto older laptops longer instead of trading them in for new models, which means a bigger market for replacement batteries.

H-P has not announced pricing yet, but, says Lampe-Onnerud, sheâ''s assured that itâ''s quite reasonable.

Caption: Boston-Power founder Christina Lampe-Onnerud

Many Young People "Digitally Hard-wired" Since Childhood

A new book by a U.S. psychiatrist argues that new technology may be physically changing the way our brains work.

In iBrain: Surviving the Technological Alteration of the Modern Mind (HarperCollins 2008), Dr. Gary Small and wife Gigi Vorgan argue that young people who have grown up with videogames, text messaging, websites, and the other trappings of the virtual world are beginning to show signs of behavioral differences compared to previous generations.

Small, the Director of the Memory and Aging Research Center at the University of California at Los Angeles, says research shows that twenty-somethings are developing unique brains in response to a nonstop cycle of information overload. Still, while this high-speed mental activity may be leading to a cohort of wired overachievers, it does have its negative side effects: attention deficit disorder, social isolation, and online addiction, among others.

The authors write: "Besides influencing how we think, digital technology is altering how we feel, how we behave, and the way in which our brains function."

In an interview with the Associated Press, Small admits that his theory has not been proven but that constant exposure to digital technologies most likely is at the root of much of the social dysfunction witnessed in classrooms and workplaces by the younger set.

Small calls this group digital natives, those who have been "digitally hard-wired since toddlerhood." He says his book is aimed at helping digital natives improve their social skills, as well as making others aware of the implications of new technology on behavior.

What does Small think is the solution to too much immersive technology? It's a page right out of the behavioral psychology textbook: adaptation. And he and his co-author offer a "technology toolkit" with suggestions (such as "aerobicizing your mind") for those who have become overloaded with high-tech distractions.

If this all sounds like a contemporary update of past arguments against the perils of new technology to young minds (see the dangers of television circa 1970, for example), it's because it is. As with previous generations, youngsters today will most likely turn out fine in the long run, a little quirkier and more awkward perhaps but still just as responsible and healthy.

Just in case, though, it would not be a bad thing to remind those reaching maturity now that they need to spend a little more quality time with their friends and family in the real world.

.Tel Me What I'm Missing

I'm bewildered by all the buzz surrounding the Internetâ''s new â''.telâ'' top-level domain. This new entity, sponsored by London-based Telnic, is intended to be a global repository of contact information for individuals and businesses. The twist here is that this information will be encoded into DNS (Domain Name System) records, allowing it to be distributed to the 12 million or so name servers around the world. When folks look me upâ''perhaps as BewilderedDave.telâ''the DNS will not direct them to a Website, as it typically does. Rather, they will access my contact information directly from the records that are returned by whatever name servers their computers are using to look up IP addresses.

That much is clear. Itâ''s also apparent from the news coverage and the descriptions on Telnicâ''s Website that the company has put mechanisms in place for those with .tel domains to control access to their contact information, should they not wish all of it to be publicly available. Whatâ''s confusing is why this service would prove all that helpful to either individuals or to businesses.

Consider the scenario Telnic uses to explain how an individual using a .tel domain can guard his or her privacy. In the companyâ''s illustrative example, Alice ( meets someone named Gary. (Bob is occupied in another role.) She informs Gary about her .tel address and gives him the URL for a login page at a Website run by Telnic. He then uses Telnicâ''s Website to create a â''friend request message,â'' which gets transmitted to Alice. She receives the message, reading within it a short greeting from Gary reminding her that this â''friendingâ'' request comes from the guy she just met at the local pub. Alice then puts the wheels in motion to allow Gary to obtain access to parts of her contact information that she doesnâ''t share with the general public.

Obviously, Gary didnâ''t impress Alice enough when they first met. If he had, she surely would have just given him her phone number then and there, instead of asking him to jump through hoops.

Telnicâ''s description explains in detail how the friending scheme worksâ''how encrypted contact information is put into a subdomain of using Garyâ''s public encryption key so only he can read it. Telnic further explains that if Alice has a falling out with Gary, â''she simply stops publishing private contact dataâ'' at that subdomain. Telnicâ''s explanation is silent, however, on what to do about the fact that Gary may still retain Aliceâ''s phone number, written perhaps in a small black book.

I suppose Alice could change her phone number, cutting off Gary without irritating too many of her other friends because theyâ''ll be using the always-up-to-date to reach her from their Internet-enabled mobile phones. But how about Aliceâ''s grandmother?

To me, the friending mechanism seems too cumbersome, and the actions needed to cut someone off are too drastic. I am also skeptical about how useful it might be for reaching businesses, although they will in general publish contact information thatâ''s always freely available to the general public.

The problem is that I wonâ''t know the .tel domain name of the business I want to reach. How can I figure out the .tel name for, say, the new pizza joint that just opened down the street? Even if I remember that the name of the place is Joeâ''s Pizza, using is more likely to return information about a restaurant in Los Angeles than the one in my home town. So Iâ''d be more inclined to Google Joeâ''s Pizza, using as much information as I have about it to find its Website, where I can look up its contact information easily enough.

Perhaps Iâ''m just too mired in late-20th-century thinking to see the value of the new service. Somebody please tell me what Iâ''m missing.

Nanosystems Author Launches His Own Blog

Some of those who read Eric Drexlerâ''s books like Nanosystems or Engines of Creation were so inspired by his vision of molecular manufacturing they started websites and blogs promoting many of his ideas.

Now we can get the up-to-date thoughts of Drexler on a broad range of subjects concerning science and technology on his new blog Metamodern.

It will be interesting to see if Drexler and his disciples see eye-to-eye on a number of subjects.

It reminds me of a scene from Martin Scorseseâ''s The Last Temptation of Christ, when Jesus gets the opportunity to confront Paul and argue that he did not die on the cross and was not resurrected. To which Paul replies: "I donâ''t care whether you are Jesus or not. The resurrected Jesus will save the world and thatâ''s all that matters.... I created the truth out of what people needed and what they believed."

As recently as last year, Drexler seemed to be opening up the possibility that the avenue towards atomically precise manufacturing may not necessarily be through self-replicating assemblers (nanobots).

Despite this nanobots have seemingly taken on an unavoidable consequence in the publicâ''s image of nanotechnology. It seems to have become what they need and what they believe when it comes to the subject of nanotechnology. Then again science is not quite like religion, itâ''s a little more difficult to create the truth.

The Armor of the Future is Armani

The soldier is modeling the 2030 Future Soldier Concept at the ASC 2008 exhibition hall, which runs from about 10:00 am until 6:30 pm. Showing off his Star Wars attire, he's all good posture and game face, but when I run into him in the elevator at the end of the day, he looks like he wants to unzip his own skin. I assume it's because the faux armor is heavy. "No," he says miserably. "The fabric is really itchy." But the next morning he's back, and you would never know he's remotely uncomfortable. That Army training is formidable.

Before you get too excited, I should mention that this is what the US Army plans to put on our soldiers around 2030. If you want to see it before that, you'll have to stick with your local Star Wars convention.

The material may not be carbon nanotube fiber with electronic-based ink circuits, but it is in fact Armani. Dutch Degay of the US Army Natick Soldier Research, Development and Engineering Center in Massachussetts says his group got it as part of a last run of Armani fabric because it was such a perfect visual match for the nanotube fiber and e-ink circuit material they wanted for their concept demonstration. When they first got the material, it was a lovely shade of cream. Then they heated it up to 140 degrees so that it could be dyed the tasteful brown shade you see above. "We totally ruined it," Dutch says, a little spitefully.


Tech Talk

IEEE Spectrum’s general technology blog, featuring news, analysis, and opinions about engineering, consumer electronics, and technology and society, from the editorial staff and freelance contributors.

Newsletter Sign Up

Sign up for the Tech Alert newsletter and receive ground-breaking technology and science news from IEEE Spectrum every Thursday.

Load More