Barcode Libary Usage
In Android device, the third-party app can use android bar code scanning and decoding api or some open source barcode libary. ZXing and ZBar are both open-source to scan barcodes or 2-D "graphical barcodes" and retrieve the data encoded.
ZXing
Supports decoding and generating of barcodes (like QR Code, PDF 417, EAN, UPC, Aztec, Data Matrix, Codabar) within images.. Please refer to https://archive.codeplex.com/?p=zxingnet.
ZBar
An open source software suite for reading bar codes from various sources, such as video streams, image files and raw intensity sensors. It supports many popular symbologies (types of bar codes) including EAN-13/UPC-A, UPC-E, EAN-8, Code 128, Code 39, Interleaved 2 of 5 and QR Code. Please refer to http://zbar.sourceforge.net/.