Australian currency note identifier for the vision impaired: Part I hardware description

摘要

Polymer notes recently replaced Australia's decimal paper currency. The denominations of the new notes, while very distinctive in their colour and design, are very difficult to differentiate for a vision impaired person. All notes are of equal width and increase only slightly in length with increasing value. The article describes the design and development of a prototype device to identify Australian polymer banknotes, which indicates the denomination to a vision impaired person using a digitally recorded voice output. Use is made of a charge-coupled device (CCD) linear array and a digital signal processing (DSP) chip. Identification is performed by imaging and recognising the contents of the clear window found near the lower corner of each note which is unique for each denomination. This development is of significance in Australia to people who suffer a large degree of vision impairment, and possibly also to the vision impaired population of the European Union, which may also plan to adopt polymer note technology.