Compression of executable QR codes or sQRy for Industry: an example for Wi-Fi access points

TL;DR

The paper addresses the payload constraint of executable QR codes used in industrial settings by introducing a simple, extensible dictionary-based compression for strings within the sQRy framework. It integrates the compression into the QRtree dialect, enabling concatenation of constant and dictionary substrings and header-stored dictionaries while supporting ASCII-7 and UTF-8 encodings. Through a Wi-Fi access point example, the authors demonstrate substantial string space reductions and a smaller overall QR size, highlighting practical gains for offline interactive configurations. The work emphasizes extensibility and outlines future improvements that maintain compatibility with the existing sQRy execution chain. Overall, this approach broadens the practical applicability of sQRy in environments with limited connectivity and tighter payload budgets.

Abstract

Executable QR codes, or sQRy, is a technology dated 2022 that permits to include a runnable program inside a QR code, enabling interaction with the user even in the absence of an Internet connection. sQRy are enablers for different practical applications, including network equipment configuration, diagnostics, and enhanced smart manuals in industrial contexts. Many other non-industry-related fields can also benefit from this technology. Regardless of where sQRy are used, text strings are among the most commonly embedded data. However, due to strict limitations on the available payload, the occupancy of strings limits the length of the programs that can be embedded. In this work, we propose a simple yet effective strategy that can reduce the space taken by strings, hence broadening sQRy applicability.

Figures (4)

• Figure 1: Generation and execution chain of sQRy.
• Figure 2: sQRy of the program reported in Fig. \ref{['fig:high_level']}.
• Figure 3: Encoding of header and strings to improve compression (in the example all the strings are coded in ASCII-7).
• Figure 4: High-level representation of the code included in the sQRy.