Login for a greater good

When you want to post a comment to a blog or send an email from a relatively new email account, you have to type in a series of distorted letters and numbers (a CAPTCHA) to prove you're a person and not a computer looking to add comment spam to a blog.

What if – instead of wasting your time and energy on typing ‘SGO9DXG’ you could label an image that will help someone who is visually impaired go shopping?

That’s exactly what computer scientists from UC San Diego led by computer science professor Serge Belongie are working on. They are presenting this work at a computer vision conference in October in Rio (ICCV 2007).

The image describes one of the many useful tasks that could be done by people who are proving that they are live humans and not computers trying to put spam comments on a blog. These kinds of labeling tasks are time consuming but important for Belongie's Grozi project -- which is an effort to create a grocery shopping assistant for the visually impaired (2006 press release).

You can download the PDF of the paper here.

Here is the press release.

Parlez-vour francais? Read the story in on the French tech site: L'Atelier

This work is related the work from Luis von Ahn that has been described by the BBC, TechCrunch and others.

"Google for Music"

When engineers put the words "indie" and "Backstreet Boys" in the same sentence in an academic paper, you got to take notice.

"For example, a pre-teen girl might consider a Backstreet Boys song to be ‘touching and powerful’ whereas a dj at an indie radio station may consider it ‘abrasive and pathetic’."

-from Identifying Words that are Musically Meaningful, by David Torres, Doug Turnbull, Luke Barrington and Gert Lanckriet from UC San Diego’s Jacobs School of Engineering.

The UC San Diego electrical engineers and computer scientists used the Backstreet Boys to highlight the subjective nature of music. This subjectivity makes it tricky to teach a computer to label songs with words. Should the computer label a Backstreet Boys song as if it were a pre-teen girl? or a dj at an indie radio station? If you want to find out, check out the paper. It is one of three papers the UCSD group is presenting at a music information retrieval conference (ACM ISMIR) this week in Vienna.

Beyond the Backstreet Boys, the researchers are working on a music search engine that lets you type in words and get acutal songs in return. One of the main things they are reporting at the conference in Vienna is that their online game (it's called Listen Game) is good for collecting data that they need to train their computer system to automatically label songs (with no input from humans, except for the initial training.) Read the full press release here.

They are now working on new versions of the games. The original version, Listen Game, works well, but, as the authors told me, "it was made my a bunch of engineers." (Read: it looks like an old-school video game and it doesn't exactly measure up to today's coolest online games.)

You can check out the old version of Listen Game here.

If you want to get an email (no spam, I promise) when the new version of the game comes out, send an email to gert@ece.ucsd.edu

Papers presented at ISMIR 2007:
A Game-Based Approach for Collecting Semantic Annotations of Music
http://cosmal.ucsd.edu/~gert/papers/MusicGame_short.pdf

Identifying Words that are Musically Meaningful
http://cosmal.ucsd.edu/~gert/papers/MusicVocab_ISMIR07.pdf

A Supervised Approach for Detecting Boundaries in Music using Difference Features and Boosting
http://cosmal.ucsd.edu/~gert/papers/MusicalBoundryDetection.pdf

UCSD at TechCrunch

App2You, a UCSD startup that spun out of the computer science department landed on the TechCrunch 40 list this week. I'm not suprised. Their Web 2.0 app is super cool. It lets you build a database driven Web site without doing any coding. I'm especially fond of this idea since I actually tried to learn all the client-server and Web coding necesseary to do this kind of thing -- back in 2001 -- right before the first Internet bubble burst. Anywhow, I wrote about App2You for the alumni magazine for UCSD's Jacobs School of Engineering. I will probably put up a story on the Jacobs site about them being named to the TechCrunch list...but you heard it here first!

By the way, if you check out the app2you site, the two guys who are on the front cover are actually two of the computer science students who helped UCSD computer science professor Yannis Papakonstantinou develop the core technology behind this company.

Computer Graphics Research featured in Science

Henrik Wann Jensen, a computer science professor at UC San In the news section of the 17 August, 2007 issue of the journal Science.

If you have access to the content behind the Science wall, you can read the story here.

For visual-effects creators, rendering objects like the mist-emitting Pensieve in Harry Potter is no mean feat. Even creating a realistic glass of milk can take computer artists hours of tedious work. But a new image-generating technique may accurately replicate many substances given only the type and amount of their ingredients.

"If we know what it's made of, we can say what it looks like," says computer scientist Henrik Jensen of the University of California, San Diego, who outlined the technique last week at a computer-graphics conference in San Diego.

Jensen, who won a 2004 Academy Award for a novel method of rendering skin that was used to create The Lord of the Rings' Gollum, worked with colleagues from the Technical University of Denmark in Lyngby to broaden a 100-year-old model of optical scattering called Lorenz-Mie theory. The team extended it to include irregularly shaped particles like the constituents of milk, seawater, and other light-absorbing substances.

The technique can also be run in reverse to derive a substance's composition from digital photographs. Commercially, this could make it possible to spot spoiled or contaminated food. A Danish company, Danisco, is interested in using it to check the freshness of milk and ice cream.

Wireless Research Featured in Technology Review

The "taking the Why out of Wi-Fi" research (see post below) landed on the front of the Technlogy Review page this week. Check out the story here


Watching Wi-Fi: This schematic illustrates the Wi-Fi access points (in red) and the radios (in black) that monitor traffic in the computer-science building at UCSD. Below: two traffic-monitoring radios on a wall. Credit: University of California, San Diego

Taking the Why out of Wireless

"People expect WiFi to work, but there is also a general understanding that it’s just kind of flakey,” said Stefan Savage, one of the UCSD computer science professors who led development of an automated, enterprise-scale WiFi troubleshooting system for UCSD’s computer science building. The system is described in a paper presented last week in Kyoto, Japan at ACM SIGCOMM, one of the world’s premier networking conferences.


“If you have a wireless problem in our building, our system automatically analyzes the behavior of your connection – each wireless protocol, each wired network service and the many interactions between them. In the end, we can say ‘it’s because of this that your wireless is slow or has stopped working’ – and we can tell you immediately,” said Savage.

"Our system is the ultimate laboratory for testing new wireless gadgets and new approaches to building wireless systems. We just started looking at WiFi-based Voice-Over-IP (VOIP) phones," Savage said.

You can read more about this here.

Stefan Savage is a UCSD computer science professorand one of the leaders of the UCSD wireless monitoring project.

Digital Dandelions Bloom in Japan

Digital dandelions are blooming at SIGCOMM 2007 in Kyoto, Japan. This paper is about creating random maps of the Internet that capture things like the interconnectivity characteristics of the actual Internet. One of the things they measure is "betweenness." Between you and me, I'm a big fan of "betweenness." You can read the press release or go to the actual SIGCOMM paper.