Steerable Projector Calibration

A steerable projector is a digital projector whose beam can be moved under computer control to illuminate different objects in its environment. Various projects have explored the possibilities of steerable projectors but they have not addressed the calibration of a generalized optical and mechanical system. We present a method for calibrating a device comprised of a projector and a pan-tilt mirror. It starts by obtaining the internal parameters of a camera and the projector, then the pan-tilt mirror is placed in a series of positions and for each one the reflected projector position is calculated from a pattern projected onto a planar surface. From those readings a coarse version of the steerable projector parameters is obtained, which is then iteratively refined. We describe real results from our physical setup and a range of results from simulated data to characterize the performance of our algorithm.