The analysis of the depth coordinates of objects in a visual scene is of vital importance for animals as well as in technological applications like autonomous robot navigation or product quality control. In this article we describe a phase-based algorithm for stereoscopic depth analysis which utilizes IIR-filters.1 This algorithm is especially well suited to be built into dedicated VLSI-hardware and can therefore, also be used as a fast realtime front end in any more general image processing system. Example movies which demonstrate the real-time capabilities of this algorithm can be found at: http://www.cn.stir.ac.uk/Real-Time-Stereo.