Paper on RGBC-IR color filter array

Tripurari Singh, Image Algorithmics (US); Mritunjay Singh, Image Algorithmics presented a paper titled "RGBC-IR: A CFA for single exposure dark flash" at Electronic Imaging 2025.

Abstract: Modern RGB-IR cameras have evolved to capture accurate colors and NIR from a single sensor. While these cameras can employ their RGB images to effectively denoise IR, they contain too few IR pixels to do the reverse: denoise RGB with IR.Improving low light RGB with an IR illuminator is an important feature for upcoming automotive applications where cabins have to be kept dark at night so as not to distract the driver. Current solutions to this problem either discard the IR cut filter and take separate RGB and IR exposures and suffer from poor colors. Or employ a bulky beam splitter architecture with separate RGB and IR sensors.We propose a camera with a novel RGBC-IR color filter array containing clear pixels that are sensitive to both visible light and IR. Its RGB pixels feature an IR attenuating coating while its IR pixels contain a black filter that blocks visible light.Mulitspectral demosaicking techniques are used to reconstruct RGB and IR images, as well as a high SNR luminance image containing the Clear, RGB and IR signals. Fusion techniques developed for beam splitter RGB-IR cameras are used to denoise RGB and IR using the luminance.