QR Code

Created: 2017-11-28


QR Codes (aka: Quick Response Code) are an extension of the more general (and often faster) Fiducial Marker that is used in Computer Vision to help identify objects based on other easy to recognize markers in an image. There are a lot of different implementations and uses with varying standards much like how barcodes have many different standards.


There doesn’t appear to be a definitive source for implementing a QR Code generator or scanner as there are many different algorithms for the different standards in existence. However, you can look at example implementations for guidelines on how to write your own implementation. Here are some commonly suggested code bases people point to for implementations:

And here are some tutorials that can hopefully provide explanations and a walkthrough:






Use Cases

Encoding Data

Many examples of different types of data that can be encoded. At the core, all of these are just bits/strings that are encoded into the QR Code. You can even encrypt it prior to encoding (for example: using passwords) for security. It’s not often used this way because QR Codes are meant to be public, but there are valid use cases for it.


Can be used here, though fiducial markers are more generally used.


Here are some public projects you can look at for implementations and example uses of QR Codes in apps.

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