A visible and near infrared (NIR) spectral reflectance database of commonly imaged objects was developed having minimal spectral redundancy. A spectral analysis was performed on this database to investigate the relationship between NIR and visible spectral reflectance. The correlation between the digital signals of theoretical NIR channels and tristimulus values for the database was analyzed to find the optimal NIR channel such that this channel could be used to improve color accuracy and improve image quality. The closer the NIR channel was located to the visible spectrum, the more optimal was the result. A colorimetric image segmentation algorithm was developed to improve this correlation. The spectral sensitivities of a typical color filter array (CFA) camera were used as a virtual camera model to test the viability of a NIR channel and colorimetric segmentation to improve color accuracy. The simulation results using the database revealed the possibility to exploiting the NIR spectral sensitivities of common CFA cameras as an additional channel for improved color accuracy.
Shizhe Shen, Roy S. Berns, Wonhee Choe, SeongDeok Lee, ChangYeong Kim, "Exploiting Color Filter Array Sensor NIR Spectral Sensitivity to Improve Color Accuracy: Spectral Reflectance Analysis" in Proc. IS&T 16th Color and Imaging Conf., 2008, pp 183 - 188, https://doi.org/10.2352/CIC.2008.16.1.art00035