Scalable Visual Codes for Embedding Digital Data in the Physical World

• 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 support 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 on Focus, a visual code that avoids earlier work's explicit trade-off between code capacity and channel quality. Rather than encoding the payload directly into individual pixels, Focus encodes the payload over a range of spatial frequencies. As a result, even a receiver with a very poor visual channel (e.g., a low-resolution camera, or a camera experiencing 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.

Subject headings

NATURVETENSKAP  -- Data- och informationsvetenskap -- Datorteknik (hsv//swe)

NATURAL SCIENCES  -- Computer and Information Sciences -- Computer Engineering (hsv//eng)

NATURVETENSKAP  -- Data- och informationsvetenskap (hsv//swe)

NATURAL SCIENCES  -- Computer and Information Sciences (hsv//eng)

Keyword

Datavetenskap med inriktning mot datorkommunikation

Computer Science with specialization in Computer Communication

Publication and Content Type

ref (subject category)

kon (subject category)