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. In one example case, the techniques are implemented in a user's computer system wherein initial threshold detection (image disturbance) and optionally user presence (e.g., 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 threshold detection and/or target presence stages can be selectively disabled for a hold-off period. The hold-off period may be, for example, in the range of 50 to 1000 mSec and triggered in response to an indication that a user of the system is unlikely to be making navigational gestures or that the system is not ready to process video, thereby conserving power by avoiding processing of video frames free of navigation gestures.