qrcode and German Umlauts

[klausbraun]

Thierry,

thank you for creating the qrcode package. I started to play around with it and found some weird behavior I don't understand.
It occurs for example when I try to use "Straße", the german word for road and written with the letter ß, in some text and create a qrcode:

library(qrcode)
code <- qr_code("Straße")
png(file="qrstrasse.png", width = 512, height = 512, units = "px")
plot(code)
dev.off()

Decoding it with zbarimg on linux, I get the QR-Code:Stra絽. Doing the same with the string "Straßeê", i.e. the word "Straße" plus an ê, decoding works fine. This is true for R on linux (version 4.3.2), and R on Windows (verison 4.2.0). Comparable behaviour can be found using other german "Umlaut" characters, i.e. Ää, Üü, Öö.

Decoding a qrcode with those characters with an Android Phone always shows ? for the german "Umlauts". Decoding it with online tools like

https://zxing.org/w/decode.jspx or
https://blog.qr4.nl/Online-QR-Code-Decoder.aspx

might work or not, depending on the tools used.

Any idea how to fix this?

Best
Klaus

[ThierryO]

I cannot reproduce the problem. Can you try the code below and post the output here? Below is the QR code I get on my machine. Can you try to scan that?

library(qrcode)
text <- "Straße"
Encoding(text)
code <- qr_code(text)
plot(code)
sessioninfo::session_info()

[klausbraun]

I'm getting the same result as with my code. zbarimg on linux gives Stra絽, and my Android device and the online decoder
https://blog.qr4.nl/Online-QR-Code-Decoder.aspx give Stra�e. https://zxing.org/w/decode.jspx works well.

The encoding command shows:

> Encoding(text)
[1] "latin1"

Session info below:

- Session info -------------------------------------------------------------------------------------------------------------
 setting  value
 version  R version 4.2.0 (2022-04-22 ucrt)
 os       Windows 10 x64 (build 17763)
 system   x86_64, mingw32
 ui       Rgui
 language (EN)
 collate  German_Germany.1252
 ctype    German_Germany.1252
 tz       Europe/Berlin
 date     2024-11-02
 pandoc   NA

- Packages -----------------------------------------------------------------------------------------------------------------
 package     * version date (UTC) lib source
 assertthat    0.2.1   2019-03-21 [1] CRAN (R 4.2.3)
 cli           3.6.2   2023-12-11 [1] CRAN (R 4.2.3)
 qrcode      * 0.3.0   2024-09-29 [1] CRAN (R 4.2.0)
 sessioninfo   1.2.2   2021-12-06 [1] CRAN (R 4.2.3)

[1] C:/Apps/R-Portable/App/R-Portable/library

---

[klausbraun]

I saw your test and I tried to do the following on my linux box where UTF-8 is the default encoding:

text <- "Straße"
Encoding(text) <- "latin1"
code <- qr_code(text)
plot(code)

This qrcode can be read and decoded by my Android device and online with zxing, even if I don't understand why.
On Windows it dosn't work because the default encoding in R seems to be Windows-1252.

[torfason]

I get the correct "Straße" code when I read the code @ThierryO posted using my iPhone.

My own R life got much easier when I configured UTF-8 as the default encoding everywhere, including in R (can be set with options(encoding = "UTF-8") if that is not the native encoding on your system).

I personally would advocate the UTF-8 Everywhere approach 😊:

• https://utf8everywhere.org