1. A method of spectral imaging comprising: obtaining color images through a sensor, comprising R, G and B color components, the color images comprising pixel values corresponding to locations in a field of view of the sensor, and being captured during corresponding illumination periods in which different LED light sources illuminate the field of view of the sensor, and the color images represent a combination of light from an LED light source and ambient light reflected from a scene in the field of view; applying a coupling factor to pixel values of the color images corresponding to a spectral channel to provide spectral channel values, wherein the spectral channel is associated with a combination of light source and a color component; summing pixel values for corresponding locations to provide sums for the corresponding locations; and for N spectral channels and the locations, computing a ratio of the spectral channel value and sum of a corresponding location to provide a spectricity vector for the corresponding location.