QR code data retrieve


A QR code uses four standardized encoding modes to store data efficiently:
We are going to talk about the binary data in the QR code. In the data part, it includes data and error correction codewords.

Here is an example from the internet: 


The 'w' is '01110111' because dark is 0 on even rows 1 on odd rows. The rows are from 0 start from bottom.



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