Design and Evaluation of LED Illumination Source for Multispectral Imaging Applications

Abstract

Multispectral imaging, which extends the number of imaging channels beyond the conventional three, has demonstrated to be beneficial for a wide range of applications. Its ability of acquiring images beyond the visible range and applicability in many different application domains lead to the design and the development of a number of multispectral imaging technologies and systems. Among these systems Light Emitting Diode (LED) illumination based multispectral imaging (LEDMSI) has received much attention in recent years due to its fast computer controlled switching ability, robustness and cost effectiveness. Scene illumination is important to successful spectral imaging. This is an often-overlooked issue and is one of the main reasons for measurement performance being compromised.Given different modes of illumination to choose from, it is important to be able to compare them in a general and in many situations specific to a certain application of interest. In this paper, we evaluate two of the important types of illumination for the rapidly growing LED based multispectral imaging systems This work provides a framework for the evaluation of ring illumination for LED based multispectral imaging systems with different ring diameters and varying number of light emitting diodes for uniform illumination, which, would be very helpful in identifying the most appropriate technique or system for a given application.