Researchers build a $7 smartphone clip-on that spots hidden cameras — AI and dynamic LED grid deliver 94% accuracy

Researchers from KAIST, formerly known as the Korea Advanced Institute of Science and Technology, who collaborated with the National University of Singapore (NUS) and Singapore Management University (SMU), have developed a clip-on LED light that works in tandem with an AI app to detect hidden cameras. According to The Chosun Daily, the team, led by Professor Han Jun of KAIST’s School of Computing, called the technology SweepLED [PDF], and it used an LED light grid that magnetically snaps to your power and an AI-powered app to analyze the image taken.

There are many ways to detect hidden cameras using your smartphone — this includes shining a flashlight around the room to spot tiny reflections coming from tiny lenses, using your phone’s camera to detect infrared emissions from hidden cameras, or using camera apps with reflection analysis. However, the first two methods require manual scanning, meaning you’re likely to miss something small and unnoticeable, while the last method is prone to false positives. Because of this, the research team decided to make their own solution using artificial intelligence.

First, they built a $7 (around KRW 10,000) LED grid that snaps to the back of your camera phone. These lights change direction continuously, allowing the reflections on different surfaces to move or disappear altogether as they move around. Since most cameras, including hidden ones, have a unique structure with their lenses, aperture, and sensor, they often exhibit a distinctive reflection pattern which SweepLED can reliably detect. The team tested the gadget in real-world settings, running it across 30 items, some of which have embedded hidden cameras, and it was able to achieve a 93.9% detection accuracy. This makes it a huge improvement over manual methods, which are tedious and prone to false positives.

Hidden cameras placed in private areas like restrooms, changing rooms, and even some rental properties and hotel rooms are slowly becoming a problem across the world, especially in East Asia. In fact, the issue has become so bad in South Korea that women started protesting it in 2018. So, one way anyone could protect themselves against voyeurs is to use this gadget, which is faster, more reliable, and easier to use compared to checking the area manually yourself. Unfortunately, this will not protect you against the over 40,000 security cameras all over the world that are streaming footage without any security, and the proliferation of smart glasses that are recording video and taking photos without the knowledge of people around them. Aside from privacy concerns, this also raises security issues, which is why the U.S. Air Force has banned the use of the gadgets in all its bases.