Abstract
Visually impaired people have a much higher chance of head injuries in daily life because of obstacles that cannot be reliably detected using conventional aids. We present part of a solution to this problem, using only one head mounted camera and optical flow techniques. As part of the system, a novel method to estimate the focus of expansion is presented, which also provides a metric for the quality of the estimate. The final result is a real time capable software system, which can detect obstacles at eye level.