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CovidPass: Making it badass by drawing inside the QR code
As a small, useless but fun hobby project, I wanted to try and draw something inside my EU Covid Pass QR certificate WITHOUT relying on error correction or rendering the digital certificate invalid.
TL;DR - some deflate misuse, mixed-mode alphanumeric and numeric QR encoding, mask choice override, padding the code with content that base45 encodes to numbers only and choosing them in a way to produce a meaningful image. Apparently, verifier apps are fine with it - every one I tried scans green.
This is a non-prod demo cert used for illustration of the concept with some funny images inside:
https://i.imgur.com/3JonSRX.png
Would there be any interest in me doing a post explaining how it was done?
Also, what else should I draw inside?
- hrvach 5y agoUrl link: https://i.imgur.com/3JonSRX.png https://i.imgur.com/3JonSRX.png
- severine 5y agoDefinitely interested in a writeup!
- bellyfullofbac 5y agoNeat. How about a pixel art that reads "Legit certificate of vaccination" in bad hand writing (like this[1]), but actually scans to a valid certificate? TBH I didn't even notice the skull and syringe at first glance, just a QR code. [1] https://papersplease.fandom.com/wiki/Jorji_Costava?file=Fake_passport_1160.png https://papersplease.fandom.com/wiki/Jorji_Costava?file=Fake... vs legitimate passports in the game: https://steamtradingcards.fandom.com/wiki/Papers,_Please_-_Passports?file=Papers_Please_Artwork_7.jpg https://steamtradingcards.fandom.com/wiki/Papers,_Please_-_P...
- muzani 5y agoI love it. I probably wouldn't do it, but it's interesting, especially for those of us who have been doing QR code apps for years.
- JoshMandel 5y agoWhat a delight! For sure would love to read the details.