1. A system comprising: a detecting component configured to detect incident electromagnetic radiation at a number of pixels; a number of electromagnetic radiation sources; each electromagnetic radiation source emitting at substantially one wavelength from a number of wavelengths; at least some of the number of wavelengths substantially coinciding with wavelengths in an absorption spectrum of predetermined materials; each one of the number of the electromagnetic radiation sources sequentially illuminating an area of interest; the number of electromagnetic radiation sources emitting substantially from one location; the detecting component receiving reflected/scattered electromagnetic radiation from the area of interest; a modulating component configured to modulate, with respect to time, emission from said each one of the number of electromagnetic radiation sources; a timing component configured to provide a signal for initiation of emission from a selected one of the number of electromagnetic radiation sources; the timing component also configured to provide said initiation signal for initiating detection by the detecting component; and an analysis component configured to: process a number of pixelated images, the number of pixelated images obtained by sequentially illuminating an area of interest, each sequential illumination being from one of the number of electromagnetic radiation sources, said one emitting at substantially one wavelength from the number of wavelengths; processing comprising subtracting, at each pixel from the number of pixels, a background image pixel value from a pixel value for detected reflected/scattered electromagnetic radiation; the subtraction producing a background subtracted value at said each pixel; the number of pixelated images, after processing, constituting, at said each pixel from a number of pixels, a vector of processed data; each element of said vector at one pixel being one of a ratio or differential between a value at one wavelength from the number of wavelengths and a value at another wavelength from the number of wavelengths; at said each pixel, thereby forming a vector of ratio or differential values at said each pixel; and compare, at each pixel, the vector of processed data to a predetermined vector corresponding to a predetermined material; presence of the predetermined material being determined by comparing.