OUDON / rmqrcode-python

Rectangular Micro QR Code (rMQR Code) Generator in Python

Rectangular Micro QR Code (rMQR Code) Generator

The rMQR Code is a rectangular two-dimensional barcode. This is easy to print in narrow space compared to conventional QR Code. This package can generate an rMQR Code image. This is implemented based on ISO/IEC 23941: Rectangular Micro QR Code (rMQR) bar code symbology specification.

🎮 Online Demo Site

You can try this online: https://rmqr.oudon.xyz .

📌 Notice

• To read rMQR code, we can use QRQR app. However many other QR code readers may have not been supported yet.
• Please verify an image generated by this software whether it can decode correctly before use.

🚀 Installation

pip install rmqrcode

📕 Basic Usage

CLI

Generate an rMQR Code image from your command line, use rmqr command:

rmqr "Text data" "my_qr.png"

See the help to list the options:

➜ rmqr -h
usage: rmqr [-h] [--ecc {M,H}] [--version VERSION] [--fit-strategy {min_width,min_height,balanced}]
            DATA OUTPUT

positional arguments:
  DATA                  Data to encode.
  OUTPUT                Output file path

optional arguments:
  -h, --help            show this help message and exit
  --ecc {M,H}           Error correction level. (default: M)
  --version VERSION     rMQR Code version like 'R11x139'.
  --fit-strategy {min_width,min_height,balanced}
                        Strategy how to determine rMQR Code size.

Generate rMQR Code in scripts

Alternatively, you can also use in python scripts:

from rmqrcode import rMQR
import rmqrcode

data = "https://oudon.xyz"
qr = rMQR.fit(
    data,
    ecc=rmqrcode.ErrorCorrectionLevel.M,
    fit_strategy=rmqrcode.FitStrategy.MINIMIZE_WIDTH
)

The ecc parameter is an enum value of rmqrcode.ErrorCorrectionLevel to select error correction level. The following values are available:

• ErrorCorrectionLevel.M: Approx. 15% Recovery Capacity.
• ErrorCorrectionLevel.H: Approx. 30% Recovery Capacity.

The fit_strategy parameter is enum value of rmqrcode.FitStrategy to specify how to determine size of rMQR Code. The following values are available:

• FitStrategy.MINIMIZE_WIDTH: Try to minimize width.
• FitStrategy.MINIMIZE_HEIGHT: Try to minimize height.
• FitStrategy.BALANCED: Try to keep balance of width and height.

Here is an example of images generated by each fit strategies for data Test test test:

Save as image

from rmqrcode import QRImage

image = QRImage(qr, module_size=8)
image.show()
image.save("my_qr.png")

📙 Advanced Usage

Select rMQR Code size manually

To select rMQR Code size manually, use rMQR() constructor.

from rmqrcode import rMQR, ErrorCorrectionLevel
qr = rMQR('R11x139', ErrorCorrectionLevel.H)

R11x139 means 11 rows and 139 columns. The following table shows available combinations.

	27	43	59	77	99	139
R7	❌	✅	✅	✅	✅	✅
R9	❌	✅	✅	✅	✅	✅
R11	✅	✅	✅	✅	✅	✅
R13	✅	✅	✅	✅	✅	✅
R15	❌	✅	✅	✅	✅	✅
R17	❌	✅	✅	✅	✅	✅

Encoding Modes and Segments

The rMQR Code has the four encoding modes Numeric, Alphanumeric, Byte and Kanji to convert data efficiently. We can select encoding mode for each data segment separately. The following example shows how to encode data "123Abc". The first segment is for "123" in the Numeric mode. The second segment is for "Abc" in the Byte mode. We can select an encoding mode by passing the encoder_class argument to the rMQR#add_segment method. In this example, the length of bits after encoding is 47 in the case combined with the Numeric mode and the Byte mode, which is shorter than 56 in the Byte mode only.

from rmqrcode import rMQR, ErrorCorrectionLevel, encoder
qr = rMQR('R7x43', ErrorCorrectionLevel.M)
qr.add_segment("123", encoder_class=encoder.NumericEncoder)
qr.add_segment("Abc", encoder_class=encoder.ByteEncoder)
qr.make()

The value for encoder_class is listed in the below table.

Mode	Value of encoder_class	Characters
Numeric	NumericEncoder	0-9
Alphanumeric	AlphanumericEncoder	0-9 A-Z \s $ % * + - . / :
Byte	ByteEncoder	Any
Kanji	KanjiEncoder	from 0x8140 to 0x9FFC, from 0xE040 to 0xEBBF in Shift JIS value

Optimal Segmentation

The rMQR.fit method mentioned above computes the optimal segmentation. For example, the data "123Abc" is divided into the following two segments.

Segment No.	Data	Encoding Mode
Segment1	123	Numeric
Segment2	Abc	Byte

In the case of other segmentation like "123A bc", the length of the bit string after encoding will be longer than the above optimal case.

🤝 Contributing

Any suggestions are welcome! If you are interesting in contributing, please read CONTRIBUTING.

📚 References

• Rectangular Micro QR Code (rMQR) bar code symbology specification: ISO/IEC 23941
• rMQR Code | QRcode.com | DENSO WAVE
• Creating a QR Code step by step

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The word "QR Code" is registered trademark of DENSO WAVE Incorporated.
http://www.denso-wave.com/qrcode/faqpatent-e.html