An imaging directional backlight apparatus including a waveguide, a light source array, for providing large area directed illumination from localized light sources. The waveguide may include a stepped structure, in which the steps may further include extraction features optically hidden to guided light, propagating in a first forward direction. Returning light propagating in a second backward direction may be refracted, diffracted, or reflected by the features to provide discrete illumination beams exiting from the top surface of the waveguide. Viewing windows are formed through imaging individual light sources by waveguide facets and rear reflector images in cooperation. Viewing windows may be provided at first and second different window planes to improve uniformity in a lateral direction. Further, stray light may be reduced by inner and outer portions of reflective facets with different inclinations for the rear reflector.