Fast Camera Motion Estimation for Hand-Devices and Applications

In this paper we present an efficient motion estimation algorithm for camera-enabled handheld devices, such as mobile phones and PDAs. Compared to general camera motion estimation, the estimation of ego-motion of handheld devices presents unique challenges because most devices are limited in resources (processing power, memory and battery). The algorithm must be lightweight so it can be efficiently embedded and run fast enough to produce smooth seamless translation. Our solution includes a multi-resolution scheme which searches the match from coarse to fine; and optimization of the search space. As a demonstration, we implemented the algorithm on the Symbian based Nokia 3650/6600 camera phone, and explored several interesting applications, including using camera motion for browsing documents and as a pointing device. A cross-platform implementation is also discussed.