1. A method for using a single-pixel imager to reconstruct the spatial appearance of a scene, the method comprising: configuring a light filtering device comprising an array of imaging elements to a spatially varying optical filtering process of incoming light according to a series of spatial patterns corresponding to a series of sampling functions that enable spatial reconstruction of an image of the scene; said light filtering device is a transmissive filter including a first membrane, a second membrane, and a variable gap therebetween; tuning a controller for manipulating a variable dimension of said gap; measuring, using a single photodetector of the single-pixel imager, a magnitude of an intensity of said filtered light across pixel locations in said series of spatial patterns; reconstructing an image of the scene from a sequence of intensity values; wherein said tuning of said controller and said gap defines a dimension having a resultant associated wavelength band transmission for controlling multi-spectral imaging; wherein a first associated wavelength band transmission is controlled by a first selected gap defining a first wavelength band of said wavelength band transmission to said single photodetector; and, wherein a second associated wavelength band transmission is controlled by at least a second selected gap defining a subsequent at least a second wavelength band of said wavelength band transmission to same said single photodetector.