Ellington

There are no Harry Potter moving holograms or Narnia-transporting wardrobes to report just yet. However, breaking the waves is a joint project among computer-science researchers and students at the UW and Cornell University. The team’s goal? To process a collection of 2-D digital photos into 3-D building reconstructions. And, as anyone closely following the project will tell you, it’s pretty magical.

Noah Snavely, a professor at Cornell University who coined the phrase “photo tourism” (licensed by Microsoft as Photosynth), used Kathleen Tuite, a UW graduate student in computer science and engineering (CSE), as his echo. Branching off of this idea of photo tourism was her project PhotoCity, a game that cleared room on the platform for students to interact.

“We are trying to reconstruct the whole world in 3-D,” Tuite said. “Or at least parts of it, for now. We can make 3-D models from a bunch of computer-vision techniques developed here at UW, but to get a really big model, we need an extremely large number of photos. Since almost everyone these days has a camera on them — point-and-shoot digital camera, even a cell phone — we figured we’d try and tap into this resource of humans and their cameras to collect the photos to make really cool 3-D models.”

PhotoCity is a game that allows people to take pictures around campus, grow the models, capture flags as the models grow and even “own” the buildings.

Upon signing up for the game online, participants can declare team affiliations — red, yellow, blue, green. Then, after further site navigation, they can stumble upon a host of interactive tools such as forums and chat rooms available to organize team information. The site offers participants a few different directions they can go with in the game: you versus another player, your team color versus all the other teams, or, as Tuite threw in, “UW versus Cornell.”

Participants might not immediately associate feelings of victory with photographing buildings and reconstructing them in their entirety. But PhotoCity regular and CSE graduate student Erik Andersen has enjoyed playing the game since it came out.

“I feel a strong sense of accomplishment when I am able to reconstruct a model of a building, grow the model so that it goes all the way around the building and expand models to other buildings,” Andersen said.

Andersen, who belonged to the same research group as Tuite, has followed the project from its humble beginnings. And while he admits to not being a component in the development of the project, he has allowed it to flourish through other means, or “rabid playing,” as Tuite puts it.

By contributing thousands of photos, the project was able to take off and even become somewhat of a competition among players.

“A rivalry has developed between me and Daniel Leventhal, a fellow CSE Ph.D. student, and this frequently motivates me to take pictures of areas of buildings that he has currently captured so that I can steal flags from him,” Andersen said.

Leventhal can see beyond the mere fun and games of it all, however, understanding that in offering his hand at the game, he is helping to debug it. Leventhal, like Andersen, stood before Tuite as she originally pitched the idea of the 2-D reconstruction project. He wanted to see it soar.

“I thought the reconstructions were fun to explore, so I took an interest in the game,” he said. “I also know how hard it is to test software that will be used by other people. As soon as someone else uses your software, they usually uncover a bunch of bugs. I wanted to help Kathleen and the PhotoCity team by testing their stuff as much as I could and try to provide useful feedback.”

CSE junior Nadine Aurora Tabing worked in the arena of debugging and customer service. Her role involved much of the project’s game design and user studies and even asking people to play the game.

“I would ask them to narrate their thought process as they went through the Web site and played the game, and [I] listened to what they found difficult or confusing or not fun about the way the game was presented,” she said. “Maybe one of the game’s instructions would be unclear, for example. Or, in the beginning, the map controls were pretty small, and people ended up not seeing them and therefore not knowing they could zoom in on the map and see the game’s flags more clearly. I also help maintain some parts of the Web site.”

CSE junior Sylvia Tashev follows some of these same roles: making the Web page easy to use and organized, and in particular, making the page for teams a center for all player- and team-related data. It’s common for her to work alongside Tuite and the rest of the team.

“[I work with them to] make it interesting to those involved, attract and retain more players and encourage players to keep participating whether for the sake of competition or just the joy of contributing to building the 3-D models,” Tashev said.

What makes this project accessible to students is the emergence of the PhotoCity iPhone application. It was created by graduate student Dun-Yu Hsiao, who says that significant strides are being made by using this medium.

“A few weeks ago, people were able to create new seed buildings all over the world from the Web site. Now, people can submit new seeds directly from their iPhones,” Hsiao said. “The goal for this application is to make PhotoCity playable everywhere, anytime, and get the game much closer to people. People might not take a camera every day, but they probably always have their cell phones with them. With a mobile-version game, people are able to access the game everywhere. That speeds up the completion of the goal of PhotoCity: to reconstruct everywhere in the world in 3-D.”

The team has its suspicions — and a few fingers crossed — that the project will be as far-reaching as its goal of “reconstructing the entire world.” In any case, PhotoCity is grabbing the attention of folks nationwide and inspiring new technological research.

“The thing that I hope PhotoCity inspires more of is the re-presentation of other powerful technologies so that they’re easier and more fun for normal people to use,” Tabing said. “When you think about it, it’s pretty amazing. Without knowing anything about computer graphics or computer vision or modeling, your average person can reconstruct a building in 3-D. And since there are tons upon tons of normal people, you can get tons of data (i.e., pictures) essentially for free, as long as you make things easy and fun.”

Reach reporter Colin Gorenstein at lifestyles@dailyuw.com.