Traditional bar codes and RFID tags have proved their worth many times over, but can we do better? Seeking an answer to that question, MIT researchers have come up with a tiny light-emitting device that can contain many times the information of a bar code and can be read at a greater distance.

The breakthrough invention, called Bokode, may not replace the deeply entrenched bar code or RFID tags any time soon, but it could open the door to a new generation of applications that would communicate personal information as well as location and motion. Bokodes can be read from a distance of 3 meters by any camera, including a cell phone camera that is equipped to decode the information.

“Bar codes require laser scanners, but now everyone has a cell phone with a camera. So why not think of a new way to tag things?” said Quinn Smithwick, a post-doctoral researcher at the MIT Media Lab, who is working on the project. “RFID tells you something is there, but not where it is. And you need a special RFID reader.”

A light-emitting Bokode is 3 millimeters in diameter and 8 millimeters thick. Efforts are under way to get the thickness down to a millimeter or two, said Smithwick. There is a parallel development track to create a light-reflecting Bokode, which could be made as thin as a film, he explained.

A light-emitting Bokode sends out a cone-shaped beam that is captured by the camera at any of several angles. The angle of light capture can indicate information about motion.

It is important that the camera focus on infinity so the light source appears blurry. It’s the blur that contains the information. The name "Bokode" comes from the Japanese photography term "bokeh," which refers to the round blob produced in an out-of-focus image of a light source.

With the concept proven, the researchers are starting to imagine a plethora of real-world applications using Bokode. For example, shoppers could point their cell phone cameras at items on shelves to obtain detailed product information including price comparisons from several items at once. Museum exhibit labels that are Bokode-enabled could send out information about the items on display. Medical information could be contained on a Bokode-enabled bracelet and read by emergency care providers.

In addition, the devices could capture motion to create video games or computer-generated movie scenes. Typically, video cameras record a person's or object’s motions using colored dots or balls attached to various parts of the person’s body. The Bokode system would allow the camera to record very precisely not just the position but the angle of each tag with much higher accuracy than conventional methods.

Bokode prototypes cost about $5 each, but that price could easily drop to 5 cents once they are produced even in volumes of a few hundred units, according to MIT researchers. A paper on Bokode will be presented in August 2009 at the SIGGRAPH conference in New Orleans. The paper is titled "Bokode: Imperceptible Visual Tags for Camera-based Interaction from a Distance," and is written by Ankit Mohan, Grace Woo, Shinsaku Hiura, Quinn Smithwick and Ramesh Raskar. The group's Website is http://cameraculture.media.mit.edu/.