A device including: an image sensor for imaging an object field reflected from an object to be imaged; a first objective lens for focusing a background field from the object into a concentrated energy field on a spatial frequency plane of the first objective lens; and a programmable spatial light modulator positioned in an optical path at the spatial frequency plane, the programmable spatial light modulator being programmed to display an opaque region and a substantially transparent region outside of the opaque region, the opaque region corresponding to a position of the concentrated energy field.