Mobile Visual Aid Tools for Users with Visual Impairments

In this chapter we describe “MobileEye”, a software suite which converts a camera enabled mobile device into a multi-function vision tool that can assist the visually impaired in their daily activities. MobileEye consists of four subsystems, each customized for a specific type of visual disabilities: A color channel mapper which can tell the visually impaired different colors; a software based magnifier which provides image magnification as well as enhancement; a pattern recognizer which can read currencies; and a document retriever which allows access to printed materials. We developed cutting edge computer vision and image processing technologies, and tackled the challenges of implementing them on mobile devices with limited computational resources and low image quality. The system minimizes keyboard operation for the usability of users with visual impairments. Currently the software suite runs on Symbian and Windows Mobile handsets. In this chapter we provides a high level overview of the system, and then discuss the pattern recognizer in detail. The challenge is how to build a real-time recognition system on mobile devices and we present our detailed solutions.