How Are LED Illumination Based Multispectral Imaging Systems Influenced by Different Factors?

Abstract

LED illumination based multispectral imaging (LEDMSI) is one of the promising techniques of fast and effective spectral image acquisition. Several LEDMSI systems and methodologies have been proposed in the literature. A typical LEDMSI system uses a monochrome camera, which captures images of a scene under n different color LED lights, producing an n-band spectral image of the scene. RGB camera based LEDMSI systems have been proposed to speed up the acquisition process. However, demosaicing process in these systems affects the spatial accuracy, and in turn influences the quality of resulting spectral images. In this paper, we study how the performance and quality of LEDMSI systems are influenced by different factors. Four major factors: camera type, demosaicing, number of color LEDs and, noise are considered in the study. We carry out simulation experiments using monochrome and RGB camera based LEDMSI systems, under the influence of different amounts of noise and practical constraints on the number of different color LEDs. The experiments confirm the influence of these factors on the performance of a LEDMSI system. We believe that this work would be useful not only in designing LEDMSI systems, but also in developing quality framework(s) for the evaluation of spectral images and spectral imaging systems.