ACamera Phone Based Currency Reader for the Visually Impaired

In this paper we present a camera phone-based currency reader for the visually impaired to denominate face values of the U.S. paper dollars. Currently, they can only be identified visually and this situation will continue in foreseeable future. Our solution harvests the imaging and computational power on camera phones to read bills. Considering it is impractical for the visually impaired to capture high quality image, our currency reader performs real time processing for each captured frame as the camera approaches the bill. We develop efficient background subtraction and perspective correction algorithms and train our currency reader using the Ada-boost framework, which is efficient. Our currency reader processes 10 frames/second and achieves a false positive rate of 10^-4. Major smart phone platforms, including Symbian and Windows Mobile, are supported.