Abstract: A method of managing power usage of a depth imaging system including an image sensor having an array of pixels configured to detect light incident from a scene and an optical encoder configured to modulate the incident light detected by the pixels in accordance with an angle of incidence of the incident light. The method includes operating the system in a lower power mode corresponding to a first power consumption level, including capturing, with the pixels, image data of the scene having angle-dependent information encoded therein by the optical encoder, and identifying, based on the angle-dependent information, signature information in the image data indicative of a detection of an object within a specified depth range. The method also includes, in response to identifying the signature information, transitioning to operating the system in a higher power mode corresponding to a second power consumption level higher than the first power consumption level.