QR and Barcode library libqrean
----

What's this?

A portable QR and Barcode generation / manipulation library written in C.

!animation
!rmqr-animation

DEMO

Wasm (thanks @taisukef)

CLI Usage

Generation

``
% qrean -t rmqr Hello
███████████████████████████████
██ ▄▄▄▄▄ █ ▀ █ █ █▄█ █▄█▄█▄▄ ██
██ █ █ ██▄ ▄█▀▄▄ ▄▄ ▀█ ▄██
██ █▄▄▄█ ██▀▀▀▄█▄▄█▀█▄ █▀▀▄██
██▄▄▄▄▄▄▄█▄██ ▄ ▀▄█▀▀█▀▄ ▄▄▄ ██
██ ▄▀▀ ▀▄ ▄█▄███▀▀▄▄▀▄▀▄ █▄█ ██
██▄▄▄█▄█▄█▄█▄█▄█▄█▄█▄█▄█▄▄▄▄▄██
▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀▀
% qrean -t mQR Hello > mqr.png # CAVEAT: Outputs PNG stream for not a tty
% qrean -o qr.png Hello # You can also specify output filename
% qrean -h
Usage: qrean [OPTION]... [STRING]
Generate QR/Barcode image

General options:
-h Display this help
-o FILENAME Image save as FILENAME
-i FILENAME Data read from FILENAME
-f FORMAT Output format, one of the following:
TXT (default for tty)
PNG (default for non tty)
PPM
-t CODE Output CODE, one of the following:
QR, mQR, rMQR, tQR
EAN13, EAN8, UPCA
CODE39, CODE93
ITF, NW7
-p PADDING Comma-separated PADDING for the code

QR family specific options:
-v VERSION Use VERSION, one of the following:
1 ... 40 (for QR)
M1 ... M4 (for mQR)
R7x43 ... R17x139 (for rMQR)
R{H}x{W}
H: 7, 9, 11, 13, 15, 17
W: 43, 59, 77, 99, 139
tQR (for tQR)
-m MASK Use MASK pattern, one of the following:
0 ... 7 (for QR)
0 ... 4 (for mQR)
-l LEVEL Use ecc LEVEL, one of the following:
L, M, Q, H (for QR)
L, M, Q (for mQR)
M, H (for rMQR)
`


Detection


`
% qrean-detect qr.png # The source file must be a PNG file so far
Hello
%
`

Library Usage

`c
qrean_t qrean = create_qrean(QREAN_CODE_TYPE_QR);
qrean_write_string(&qrean, "Hello, world", QREAN_DATA_TYPE_AUTO);

size_t len = qrean_read_bitmap(&qrean, buffer, sizeof(buffer), 8);
fwrite(buffer, 1, len, stdout);
`

`c
qrean_write_pixel(&qrean, qrean.canvas.symbol_width - 1, qrean.canvas.symbol_height - 1, 0);
qrean_fix_errors(&qrean);

qrean_read_string(&qrean, buffer, sizeof(buffer));
printf("%s\n", buffer);
`

`c
qrean_t *qrean = new_qrean(QREAN_CODE_TYPE_QR);
qrean_set_qr_version(qrean, QR_VERSION_3);
qrean_set_qr_errorlevel(qrean, QR_ERRORLEVEL_M);
qrean_set_qr_maskpattern(qrean, QR_MASKPATTERN_7);

qrean_write_qr_finder_pattern(qrean);
qrean_write_qr_alignment_pattern(qrean);
qrean_write_qr_timing_pattern(qrean);
qrean_write_qr_format_info(qrean);
qrean_write_qr_version_info(qrean);
`

See examples/ directory for working examples.




JavaScript / TypeScript Usage (Powered by Wasm)

`js
import { Qrean } from 'qrean';

const qrean = new Qrean();
const img = await qrean.encode('Hello, world');
console.log(img);
// {
// width: 116,
// height: 116,
// data: Uint8ClampedArray(53824) [
// :

const { detected } = await qrean.detect(img);
console.log(detected[0].text);
// Hello, world
`

It requires Wasm to run, but don't worry, most engines support it; Node, Deno, Bun and browsers.

Install

As a CLI

* Windows
- Download from Release Page
UNIX-like systems (Linux / macOS / BSD)
- Just make install

As a JavaScript / TypeScript library

`sh
% npm install qrean
`

As a C library for embedded systems

Take a look at src/ and include (or copy) them!

Why?

As you can see, you can take control.
I love QR and Barcodes.

The core (encode/decode) doesn't rely on malloc() for portability. It uses a stack instead of a heap, but you can still use new_qrean` for example if you prefer.

You can also configure a callback to draw a pixel directly on a screen for example.

Supported codes

| type | encode | decode | detect
|---------------------|--------|--------|-----------
| QR | ✓ | ✓ | ✓
| mQR | ✓ | ✓ | ✓
| rMQR | ✓ | ✓ | ✓
| tQR | ✓ | ✓ | ✓
| UPCA / EAN13 / EAN8 | ✓ | ✓ | ✓
| CODE39 | ✓ | ✓ | ✓
| CODE93 | ✓ | ✓ | ✓
| NW7 | ✓ | ✓ | ✓
| ITF | ✓ | ✓ | ✓