Bad detection of DataMatrix about zxing-cpp

[TimZaman]

The detector is made for when the code is dead center and fairly large in view. You could try making your own pre-localisation.

[axxel]

In case that is still relevant: I had the same issue and found the c++ port from @huycn (https://github.com/nu-book/zxing-cpp. It is a completely new port based on the current Java code with the goal of having an idiomatic c++ library instead of a 1:1 mapping of Java classes.

That said, the DMDetector had the same limitations: it only works with sufficient resolution and an unrealistic requirement on the amount of whitespace surrounding the code and the orientation of the code. I reimplemented the detector from scratch and now it can detect all the samples from the test directory and more challenging examples like https://www.deutsche-apotheker-zeitung.de/_Resources/Persistent/55c53726b5bbcc918ec7800229cf2e9d27794c21/k4_931_258080_258181-800x343-660x283-482x271.jpg

I'd be happy to get feedback.

[pke]

You implementation can be tested where?

[axxel]

If you have a Linux/macOS machine, you can use the test runner project https://github.com/nu-book/zxing-cpp/tree/master/test/runners/generic to build a binary that can be called with an image path and it will try to decode that. You'll need the imagemagic convert tool in the path for internal jpg/png->pgm conversion.