1. A Lightweight Computer Vision-based Electronic Travel Aid Andrew B. Raij (raij@cs.unc.edu)raij@cs.unc.edu Enabling Tech Project Status Report 3/6/2003 Department of Computer Science, UNC-Chapel Hill

2. High-Level (Long Term?) Goal Inexpensive, lightweight device that assists with orientation and mobility (O&M) Gathers spatial data from the environment with one or more cameras and presents it to a blind user in a useful form

3. Big Questions (1) Why Cameras? NxM 2D grid of intensity / color data Find edges, other features Lots more information than ultrasound, infrared lasers, etc Wide field of view (particularly when using several cameras) Can extract long-range depth from the world (as opposed to 3-6 ft. of a cane) No need to scan the world like a cane Cameras are getting cheaper and cheaper

4. Big Questions (2) What data to gather? Intensity / Color Depth * Cane is too short Cane does not help much for high objects Patterns (brick, tile, marble, etc?) Faces Objects

5. Big Questions (3) How to transform visual data to useful information? Auditory Don’t want to affect ability to listen to the world Tactile Other?

6. Big Questions (4) How to do it fast on a small, lightweight device? Hardware Requirements Floating point ? Low heat, power Inexpensive Cameras and Camera Interface (Firewire? USB?) Possibilities PDA – no floating point, useless video display Mini PC

7. This Semester Do a lot of Learning / Reading Perception of the world by the blind Existing O&M “Devices” Existing O&M work using computer vision Experiment with Multiple View Geometry concepts Two-View Geometry Mirror Stereo Look into inexpensive, lightweight hardware platforms Begin implementation