1. A mobile or portable device comprising an illuminating arrangement comprising a light source, and an amplitude splitting interferometer configured to form an interferogram of light emitted by the light source, the illuminating arrangement being configured to illuminate a target region at a distance of at least 10 cm from the device by the interferogram, thereby projecting a structured light pattern onto the target region; an image sensor configured to capture at least one digital image frame of the target region illuminated by the interferogram; and a processing unit configured to obtain image data of the at least one digital image frame, and determine depth of at least one object location in the target region relative to a reference location on the basis of the obtained image data.