Columbia University

Technology Ventures

Image-capture system for extraction of visually encoded information

Technology #cu14328

This technology is a system for extracting information encoded by variations in light intensity from displayed images.

Unmet Need: Reliable and nonintrusive methods to provide supplementary information in visual displays

Current strategies to provide additional information, such as an associated URL, with displayed images are often limited by imposed requirements on viewer proximity and position, or overreliance on manual copying by the user. Thus, there is a need for alternative mechanisms to conveniently and reliably delivery supplementary information alongside displayed images.

The Technology: Light-based method for embedding information in visual displays does not affect design aesthetics

By temporally modulating a display’s brightness at high frequencies, messages can be coded into displayed images in a way that is imperceptible to the human eye. This technology uses a rolling shutter camera to capture the image and convert the modulated incident light into a spatial flicker pattern, which can be subsequently decoded to extract the embedded information. This method is compatible with the standard camera sensors found on most mobile devices and can be readily applied to any backlit display or advertisement, as well as illumination shone on an object, such as artwork at a museum. By digitally encoding the data in light intensity, this technology allows data to be transmitted with high accuracy regardless of any hindrances such as blurring, motion, or occlusion. Moreover, since the signal is invisible to the human eye, aesthetic design of the advertisement or visual aid is not impeded. A multitude of information can be embedded in a single image using this approach, increasing simplicity and efficiency for both advertisers and consumers.

This technology has been validated through physical simulations of a mobile phone camera with a flickering LED illumination signal in a variety of real-world settings.


  • Digital transmission of data
  • Embedding of invisible messages for detection and decoding on mobile devices
  • Embedding of URLs or other information for advertisement in visual displays
  • Transmission of information through ambient illumination of artwork or other displayed objects


  • Compatible with standard camera sensors found on most mobile devices
  • Unaffected by blur, distance, partial occlusion, or camera angle
  • Does not impede on design aspects or occupy space in graphic

Lead Inventor:

Shree Nayar, Ph.D.

Patent Information:

Patent Pending (US 20170034412)

Related Publications:

Tech Ventures Reference: