Darwin Wallet enables blind and visually impaired users to quickly recognize paper money. It uses the phone's camera to detect currency denominations for U.S., U.K., Canadian, European Union, and Australian bills. Simply hold the bill in front of the phone's camera, and the app will speak its value. The app uses the phone's camera and OpenCV (via Android NDK) to analyze and identify the currency image.
OpenALPR is an automated license plate recognition library that analyzes images and identifies license plates. The output is the text representation of any license plate characters found in the image. It uses OpenCV computer vision libraries to recognize and analyze the plate images, and the Tesseract OCR library and a specially trained character set to recognize characters.
Adding new currency should be fairly simple. Check out the format in the res/raw directory. Each of those png images correspond to a bill (front or back). Add a new language code in res/values/language_packs.xml and run it.
Most of the logic is in the C++ NDK code. That should pick up your changes and use the new Argentinian currency.