tinyzing is an open-source library to read QR-codes with embedded devices in mind. This is a simplified version of ZXing C++ Port adapted to use C++17 features.

• Compile-time defined parameters such as image size and maximum QR version;
• No dynamic allocations;
• No exceptions;

• QR Code up to version N (defined at compilation time)

OpenCV demo depends on OpenCV >= 4.0.0.

1. Edit core/src/zxing/ZXingConfig.h to define ImageWidth and ImageHeight (this must be the exact dimension of the input image) and MaxGridSize (this is used to compute the maximum supported QR version:

MaxSupportedQRVersion = (MaxGridSize - 17) / 4;

2. If necessary, edit the parameters marked as TODO - these were defined in a way that works for my case but can be probably computed from QR version.
3. In an empty build directory, invoke cmake .. to build the library and examples.

Run opencv_zxing to detect QR codes using a webcam. Position the code inside the green box and observe the resulting black matrix:

This is a preview of the ESP32 demo. For more details and actual usage check my other repo OvenCamera.