Visual Navigation for the Blind - Path and Obstacle Detection

We present a real-time vision system to assist blind and visually impaired persons. This system complements the white cane, and it can be used both indoor and outdoor. It detects borders of paths and corridors, obstacles within the borders, and it provides guidance for centering and obstacle avoidance. Typical obstacles are backpacks, trash cans, trees, light poles, holes, branches, stones and other objects at a distance of 2 to 5 meters from the camera position. Walkable paths are detected by edges and an adapted Hough transform. Obstacles are detected by a combination of three algorithms: zero crossings of derivatives, histograms of binary edges, and Laws’ texture masks.