Recovering spectral information using digital camera systems

Abstract

There is an increasing need to be able to measure colour properties of complex surfaces or images for which traditional spectrophotometers are not suitable. New multispectral imaging systems are being developed but it is not clearly understood how the parameters (such as the number of colour channels, the spectral properties of the channels, and the choice of illuminant) of such systems affect the performance. Furthermore, the effect of sensor and quantisation noise on the overall performance of the system also needs to be considered. This paper describes the development of a mathematical model of a multispectral imaging system that takes into account imaging parameters and noise. The results from the computational model show that increasing the number of colour channels alone in the imaging system does not necessarily allow better estimates of spectral reflectance. The choice of illumination can also, in the presence of noise, greatly affect performance.