In this paper we describe a new framework to control an active camera platform in order to improve the performance of tasks such as active stereo vision. This framework encompasses both calibrated and uncalibrated operations. We show how to control the camera system by making measurements as much as possible on compressed video streams. Coarse depth information, object segmentation, and focus and zoom control can be obtained from JPEG/MPEG streams without complete image stream decompression. When better accuracy is required, finer resolution depth maps can be reconstructed in the usual way by completely recovering the pixel information in the frames of the video stream. Our experimental results show the potential of these strategies for active vision systems.