1. An imaging system for obtaining snapshot images of an object in a number of different wavelength bands S, comprising: a. an image sensor having a plurality of sensor pixels in a sensor plane; b. an optical block having a disperser, the disperser providing at the sensor plane a light dispersion with a complete lateral dispersive shift Δd such that Δd matches a featuresize Δ of a spatial feature Φ of a non-dispersed image of the object formed at the sensor plane; and c. a mechanism for extracting from the light dispersion spectral-spatial data that can be converted into S images of the object in, correspondingly, S different wavelength bands.