A multispectral system based on a monochrome camera and an adaptive illumination source is presented in this paper. Its
preliminary application is focused on material discrimination for food and beverage industries, where monochrome,
color and infrared imaging have been successfully applied for this task. This work proposes a different approach, in
which the relevant wavelengths for the required discrimination task are selected in advance using a Sequential Forward
Floating Selection (SFFS) Algorithm. A light source, based on Light Emitting Diodes (LEDs) at these wavelengths is
then used to sequentially illuminate the material under analysis, and the resulting images are captured by a CCD camera
with spectral response in the entire range of the selected wavelengths. Finally, the several multispectral planes obtained
are processed using a Spectral Angle Mapping (SAM) algorithm, whose output is the desired material classification.
Among other advantages, this approach of controlled and specific illumination produces multispectral imaging with a
simple monochrome camera, and cold illumination restricted to specific relevant wavelengths, which is desirable for the
food and beverage industry. The proposed system has been tested with success for the automatic detection of foreign
object in the tobacco processing industry.