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/.
