Recently [mit41301] wondered about increasing the data capacity of QR codes, and was able to successfully triple the number of bits using color. He chose the new rectangular micro QR code (rMQR) ...

Among the many changes brought about by the pandemic is the widespread use of QR codes, graphical representations of digital data that can be printed and later scanned by a smartphone or other device.

Imagine your daily routine being entirely dependent on a smart phone app. Leaving your home, taking the subway, going to work, entering cafes, restaurants and shopping malls — each move, dictated by ...