Scalable Visual Codes for Embedding Digital Data in the Physical World
Number of Authors: 3
2015 (English)Conference paper (Refereed)
Visual codes, such as QR codes, offer a low-cost alternative to RF technology when digital data needs to be embedded in objects in the physical world. However, in order to sup- port receivers with a poor visual channel, e.g. low-resolution cameras, most visual codes are designed for low data capacity and short reading distances. We present our work-in-progress on Focus, a visual code that avoids earlier work’s explicit trade-off between code capacity and channel quality. Rather than encoding the pay- load directly into individual pixels, Focus encodes the pay- load over a range of spatial frequencies. As a result, even a receiver with a very poor channel (e.g., with low-resolution camera or motion blur) can still partly decode a Focus code, because the code’s low-frequency components are robust to common channel impairments. A receiver with a good channel can decode all data from the same code. In our demo, we will present a prototype of Focus for smartphones and showcase how it deals with common impairments of the visual channel.
Place, publisher, year, edition, pages
Computer and Information Science
IdentifiersURN: urn:nbn:se:ri:diva-24488OAI: oai:DiVA.org:ri-24488DiVA: diva2:1043572
Embedded Networked Sensor Systems (SenSys)