Recently, non-RGB image sensors gain a traction in the automotive applications for high sensitivity camera system. Some color filter combinations have been proposed, such as RCCB, RCCG, RYYCy, etc. However, some of them have a difficulty to differentiate Yellow and Red traffic signals. This paper proposes the solution to that issue by shifting Red color filter edge. The differentiation performance was verified by the segmentation in the color space using the traffic signal spectrum database we built up. This result was also checked with image data by using a hyperspectral camera simulation. For the SNR comparison between those color filter options, we propose SNR10-based scheme for an apple-to-apple comparison and discuss on the overall pros / cons.
Eiichi Funatsu, Steve Wang, Jken Vui Kok, Lou Lu, Fred Cheng, Mario Heid, "Non-RGB color filter options and traffic signal detection capabilities" in Proc. IS&T Int’l. Symp. on Electronic Imaging: Autonomous Vehicles and Machines, 2022, pp 215-1 - 215-6, https://doi.org/10.2352/EI.2022.34.16.AVM-215