• Skip to primary navigation
  • Skip to main content
  • Skip to primary sidebar
  • Skip to footer

Electrical Engineering News and Products

Electronics Engineering Resources, Articles, Forums, Tear Down Videos and Technical Electronics How-To's

  • Products / Components
    • Analog ICs
    • Battery Power
    • Connectors
    • Microcontrollers
    • Power Electronics
    • Sensors
    • Test and Measurement
    • Wire / Cable
  • Applications
    • 5G
    • Automotive/Transportation
    • EV Engineering
    • Industrial
    • IoT
    • Medical
    • Telecommunications
    • Wearables
    • Wireless
  • Learn
    • eBooks / Handbooks
    • EE Training Days
    • Tutorials
    • Learning Center
    • Tech Toolboxes
    • Webinars & Digital Events
  • Resources
    • White Papers
    • Educational Assets
    • Design Guide Library
    • Digital Issues
    • Engineering Diversity & Inclusion
    • LEAP Awards
    • Podcasts
    • DesignFast
  • Videos
    • EE Videos and Interviews
    • Teardown Videos
  • EE Forums
    • EDABoard.com
    • Electro-Tech-Online.com
  • Bill’s Blogs
  • Advertise
  • Subscribe

Computational Imaging On The Electric Grid

July 14, 2017 By American Technion Society

Researchers at the Technion-Israel Institute of Technology and the University of Toronto have developed a technology for producing a new understanding of the nighttime landscape—from the office level to the entire city—based on the flicker of electric lights.

Artificial lighting plays a central role in our lives—in the home, in the office, on the road, and more—and is produced by a variety of lamps that are found in streetlights, offices, searchlights, billboards, computer monitors and more. Light emitted from all lamps connected to the electricity grid is constantly changing, but because of the high speed of this effect, people do not sense this flickering.

In a study to be presented July 22nd at the Computer Vision and Pattern Recognition conference of the Institute of Electrical and Electronics Engineers (IEEE), lead researcher Mark Sheinin of the Technion’s Andrew and Erna Viterbi Faculty of Electrical Engineering, along with Technion Professor Yoav Schechner and Professor Kyros Kutulakos of the University of Toronto will present a new way to produce a great deal of useful information from the flicker patterns of lighted scenes. The approach combines various fields of research, including optics, computer vision, image processing and electrical grid engineering.

The researchers developed a system that extracts information from a passive video (without additional lighting) of the desired scene—office, hallway, even an entire city. The analysis of the information obtained from the photograph concludes, among other things, how the scene would look if some of the bulbs were turned off, amplified or replaced them with a different type of light, which may also help to cancel the reflections from windows. The analysis could help people take “selfies” in a restaurant and digitally eliminate a shadow-casting ceiling bulb, and vary the color and shading in the background.

Furthermore, the researchers found that the flicker across city scale provides valuable information about the electric grid itself, with potential to indicate anomalies in its dynamics. Based on this industrial application, they thus submitted a patent jointly with Technion Professor Yoash Levron.

The reason for the flicker of the light is that electrical networks operate in an alternating current (AC), in which the current of the electrons continuously reverses its direction. In North America, for example, the frequency in the grid is 60 Hz, which means that the electron current changes direction 120 times per second, and that is the rate at which the light flickers. The jitter pattern depends on the type of bulb—fluorescent, mercury, halogen, LED—since each bulb converts the electricity energy to light in a different process; in other words, each type of bulb has a unique time signature.

For photographers, flicker photography is a challenge. On the one hand, identifying the dynamics of flicker requires a very brief exposure. On the other hand, photography at night requires a long exposure to collect enough light to create an image. To solve this discrepancy, the researchers developed a unique electro-optical camera called ACam to sense the flicker of the alternating current. The camera, which is connected to the electricity grid, uses the flicker cycle to capture fast signals from the scene. The camera’s electronic shutter is open the entire time an image is taken, but the scene is only visible to the sensor in the desired time section of each flicker cycle.

The technology has developed a pathway for further research to perform a wide range of tasks, including the controlled illumination of objects, the measurement of three-dimensional objects and their surface texture based on their shadow, and the analysis of the properties of the electrical grid remotely by optical methods.

Srinivas Narasimhan, a professor in the School of Computer Sciences at Carnegie-Mellon University who was not involved with the study, said the ACam paper demonstrates “really innovative work, by measuring a signal that is hidden in plain sight and turning it into useful information. Its applications could include light pollution monitoring, air quality estimation at night, non-line-of-sight imaging, and monitoring power grid output and fluctuations.”

Professor Schechner’s interest in amateur astronomy, and the challenge light pollution poses for city star-gazers, prompted an interest in studying these subtle changes in light. Street lights flicker, so he reasoned “a way to capture the flicker could allow us to make urban night-sky observations, by integrating the brief moments that the light flicker has minimum brightness.”

But the researchers soon discovered that light bulbs don’t all flicker in the same way. “When one bulb reaches a minimum brightness, another bulb might be approaching its own maximum.”

“So the astronomical idea was shelved for the time being,” Professor Schechner added, “but we found great new uncharted territory to explore: the electrical grid.”

(Image Credit: American Technion Society)

You Might Also Like

Filed Under: Displays

Primary Sidebar

EE Engineering Training Days

engineering

Featured Contributions

Five challenges for developing next-generation ADAS and autonomous vehicles

Robust design for Variable Frequency Drives and starters

Meeting demand for hidden wearables via Schottky rectifiers

GaN reliability milestones break through the silicon ceiling

From extreme to mainstream: how industrial connectors are evolving to meet today’s harsh demands

More Featured Contributions

EE Tech Toolbox

“ee
Tech Toolbox: 5G Technology
This Tech Toolbox covers the basics of 5G technology plus a story about how engineers designed and built a prototype DSL router mostly from old cellphone parts. Download this first 5G/wired/wireless communications Tech Toolbox to learn more!

EE Learning Center

EE Learning Center
“ee
EXPAND YOUR KNOWLEDGE AND STAY CONNECTED
Get the latest info on technologies, tools and strategies for EE professionals.
“bills
contribute

R&D World Podcasts

R&D 100 Episode 10
See More >

Sponsored Content

Advanced Embedded Systems Debug with Jitter and Real-Time Eye Analysis

Connectors Enabling the Evolution of AR/VR/MR Devices

Award-Winning Thermal Management for 5G Designs

Making Rugged and Reliable Connections

Omron’s systematic approach to a better PCB connector

Looking for an Excellent Resource on RF & Microwave Power Measurements? Read This eBook

More Sponsored Content >>

RSS Current EDABoard.com discussions

  • reverse polarity circuit protection between to power sources
  • Cascade Amplifier at High Frequency
  • Keysight ADS Oscillator using Negative Resistance method
  • Equipment to see if household should buy battery/solar/inverter?
  • How to simulate a microstrip gap with such a reference plane

RSS Current Electro-Tech-Online.com Discussions

  • Fun with AI and swordfish basic
  • Epson crystal oscillators
  • Simple LED Analog Clock Idea
  • Microinverters and storeage batteries?
  • PIC KIT 3 not able to program dsPIC
Search Millions of Parts from Thousands of Suppliers.

Search Now!
design fast globle

Footer

EE World Online

EE WORLD ONLINE NETWORK

  • 5G Technology World
  • Analog IC Tips
  • Battery Power Tips
  • Connector Tips
  • DesignFast
  • EDABoard Forums
  • Electro-Tech-Online Forums
  • Engineer's Garage
  • EV Engineering
  • Microcontroller Tips
  • Power Electronic Tips
  • Sensor Tips
  • Test and Measurement Tips

EE WORLD ONLINE

  • Subscribe to our newsletter
  • Teardown Videos
  • Advertise with us
  • Contact us
  • About Us

Copyright © 2025 · WTWH Media LLC and its licensors. All rights reserved.
The material on this site may not be reproduced, distributed, transmitted, cached or otherwise used, except with the prior written permission of WTWH Media.

Privacy Policy