h3. Barcodes for spatial markup and control
“Spotcodes”:http://www.highenergymagic.com/spotcode/index.html use a very “simple circular barcode”:http://www.highenergymagic.com/spotcode/symbols.html, to mark objects for interaction with a camera equipped phone.
* Requires a “small application”:http://www.highenergymagic.com/spotcode/download.html running on a Series 60 phone to scan barcodes with the built in camera
* Each barcode can currently store 42 bits of data using technology modified from iris tracking and wavelet technologies (as far as I understood)
* Potential for more data by increasing the number of rings, but current setup is a compromise for low quality cameraphone cameras
* The mobile phone application can determine position of phone relative to barcode by the elliptical distortion of the circle, could perhaps be used for quite accurate tracking with multiple spots
* The phone application communicates via bluetooth or gprs, using the barcodes as triggers for interactions
* It’s coded ‘close to the hardware’ to use the video input to do barcode calculation in realtime: Java/Symbian apps don’t have an API to realtime video input
* In use commercially via “Bango”:http://www.bango.net
h3. Bluetooth mapping
“Reverend Rat”:http://www.spy.org.uk/ratblog/ demoed his 10 Watt bluetooth receiver, 10 times more powerful than a 35 mile 802.11b receiver, and 100 times more powerful than a Bluetooth dongle.
Not particularly interesting in itself, but using it from a high vantage point he might be able to map out usage patterns in urban areas, or track the flow of people and devices.
h3. Some photos
p(caption). Nice impromptu public markup
p(caption). Anil demonstrates test barcodes for spotcode
p(caption). Reverend Rat discovers Bluetooth devices
p(caption). Celia and Rod