Use of light-emitting diodes in multispectral systems design: variability of spectral power distribution according to angle and time of usage

Abstract

Multispectral systems allow the spectral and color characterization of objects using images obtained from several acquisition channels with different spectral sensitivities. Light sources based on light-emitting diodes have started to be used in multispectral systems, mainly to develop low-cost devices for the industry. In this study, the authors examine the variability of spectral power distribution according to the viewing angle of white and single color light-emitting diodes, which can have a significant impact on spectral and color accuracy. This must be taken into account if they are to be used in multispectral systems design. The spectrum drift according to the time of usage of white light-emitting diodes is also analyzed.