Smartphone recognition of the U.S. banknotes' denomination, for visually impaired people

We have developed the prototype of a system that recognizes the denomination of the largest U.S.A. currency notes in circulation in Ecuador, aimed at visually impaired people. It is capable of reproducing audio messages that announce the denomination of a banknote in front of a smartphone camera by processing each frame of its continuous filming. This work takes its theoretical basis from the Digital Image Processing (DIP) techniques and primarily from the image recognition method known as Eigenfaces, which is based on the Principal Component Analysis (PCA) mathematical theory. Tests on two different Nokia smartphones show an accuracy rate of 99.8% and a processing speed of at least 7 frames per second.