Techniques are disclosed for processing a video stream to reduce platform power by employing a stepped and distributed pipeline process, wherein CPU-intensive processing is selectively performed. The techniques are particularly well-suited for efficient hand-based navigational gesture processing of a video stream, in accordance with some embodiments. The stepped and distributed nature of the process allows for a reduction in power needed to transfer image data from a given camera to memory prior to image processing. In one example case, for instance, the techniques are implemented in a user's computer system wherein initial threshold detection (image disturbance) and optionally user presence (hand image) processing components are proximate to or within the system's camera, and the camera is located in or proximate to the system's primary display. The computer system may be any mobile or stationary computing system having a display and camera that are internal and/or external to the system.