Dark Light with RGBC-IR
Color Imaging in the Dark
Color imaging in the dark is challenging, as turning on a light is not feasible in many situations. Current automotive surround cameras perform poorly at night since traffic laws prohibit sideways-facing vehicle lighting. Similarly, automotive cabins cannot be illuminated at night, as this would create glare on the windshield and obscure the driver’s view of the road.
In defense scenarios, maintaining darkness can be mission-critical. Biological specimens may be photosensitive. Even when lights are permitted, they can be intrusive and disruptive.
Solution: Dark Light
Active systems that illuminate scenes with infrared light greatly outperform passive systems that rely on cameras with enhanced sensitivity to ambient light. Our system combines an infrared illuminator with an RGBC-IR camera. The RGBC-IR sensor improves upon conventional RGB-IR sensors by adding clear pixels that are sensitive to both visible and infrared light, while incorporating a specialized coating on the RGB pixels that blocks 95% of IR light. The dual bandpass IR cut filter with IR notch remains unchanged.
This innovative system, which we call “Dark Light,” is similar to Dark Flash but offers greater versatility—it does not require multiple exposures, or multiple cameras or bulky beam splitters. It’s not limited to still photography and can capture high-quality color video in low-light conditions.
Turning on the IR Illuminator
IR illumination improves the luminance signal-to-noise ratio by 20 dB in our testing. Overall chrominance quality is largely similar. While removing IR that leaks into the R, G, and B channels increases chroma noise, the improved luminance SNR makes chroma denoising more effective by clearly defining edges and preventing pixel averaging across edge boundaries.
Comparison Videos
More Information
Our EI2025 paper and its Chinese translation.