Hi HN — solo dev here. sqr.art turns an image into a QR code where the picture is the code: it's encoded into the QR's data and Reed–Solomon bits (the "QArt" approach), rendered as a colour halftone — not a logo pasted on top and hoping error correction survives it. Every code is decoded back by a real reader and URL-verified before it ships, so nothing invalid can go out.
The encoding itself is old (a 2013 SIGGRAPH Asia paper, and there are several open implementations). What actually ate my time was making these things scan off a printed page — a software decoder validates the math, not the print, and the two fail on completely different things. I wrote up the war stories (diamond dots carrying half the ink, flat logos with nothing for a phone's thresholding to grab onto, the ~4 cm print floor): https://sqr.art/blog/the-decoder-lies
You can generate a preview for free without an account — I'd genuinely like feedback on scannability with your own phone and images, especially odd cameras or small prints. Happy to go deep on any of it.
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[ 2.2 ms ] story [ 15.5 ms ] threadThe encoding itself is old (a 2013 SIGGRAPH Asia paper, and there are several open implementations). What actually ate my time was making these things scan off a printed page — a software decoder validates the math, not the print, and the two fail on completely different things. I wrote up the war stories (diamond dots carrying half the ink, flat logos with nothing for a phone's thresholding to grab onto, the ~4 cm print floor): https://sqr.art/blog/the-decoder-lies
The engine is MIT and standalone if you just want the library: https://github.com/mikaelcarlavan/qart-php (composer require sqrart/qart).
You can generate a preview for free without an account — I'd genuinely like feedback on scannability with your own phone and images, especially odd cameras or small prints. Happy to go deep on any of it.