An innovative solution has emerged for travelers concerned about privacy in accommodations. The SweepLED device, a cost-effective smartphone accessory, has been engineered to help identify hidden cameras in hotel rooms and short-term rentals.
Developed by researchers, this prototype integrates an LED-equipped phone case with computer vision and machine learning, allowing it to detect camera lenses’ optical signatures in less than five seconds.
Advanced Detection with LED Technology
Hidden cameras are often camouflaged within everyday items like clocks, adapters, and smoke detectors. Traditionally, their detection required expensive tools or labor-intensive manual methods, prone to false alarms due to reflective surfaces such as glass or metal.
The SweepLED device addresses these challenges by altering the inspection process. It attaches to a smartphone case, using a compact LED array to illuminate objects from multiple angles while the phone camera remains fixed.
Technical Insights from KAIST Researchers
The process leverages differences in light reflection between camera lenses and shiny surfaces. Camera lenses tend to produce stable reflections, unlike ordinary glossy materials. The device captures a video during LED sweeps, stabilizes it, and uses machine learning to identify potential camera lenses.
In tests involving 12 hidden-camera objects and 18 non-camera reflective items, the system achieved a detection accuracy of 93.9%, with a 7.2% false-positive rate. Each inspection, using three viewpoints, takes approximately 4.5 seconds.
SweepLED’s Practical Applications
With core components costing under $7, SweepLED presents a viable low-cost option for travelers or hotel-provided privacy tools. The prototype utilizes directional LEDs, a PWM controller, and an ATmega328P microcontroller, all controlled via an Android app.
However, SweepLED is not foolproof. Its effectiveness diminishes when lenses are obscured or when inspections occur from distances beyond 100 cm. Despite these limitations, it offers a rapid and accessible alternative to specialized equipment.
The SweepLED device represents a significant step toward enhancing privacy for hotel guests and Airbnb users, making hidden-camera detection more accessible and efficient.
