Skip to content

Latest commit

 

History

History
139 lines (98 loc) · 4.92 KB

README.md

File metadata and controls

139 lines (98 loc) · 4.92 KB
Raw

Python implementation of QR code generator.

The module generates QR Code from text file or stdin. The output image can be saved, displayed or both.

Requirements:

Python 3

External libraries:

numpy, PIL

Usage examples:

  • Create QR code from stdin and save the image.

There's only input message [-i] and output file name [-o] required and we are good to go. All the remaining parameters will be set automatically, based on the message length and its type (number, UTF-8, ASCII, etc.).

$ python3 qr_code.py -i "Hello world" -o "stdin_sample.png"
  [+] Latin-1 encoding applied.
  [+] QR version: 1 chosen.
  [+] Error Correction Level: Q chosen.
  [+] Best mask has been applied: [2]. With 342.0 penalty
  QR saved at: /absolute/path/to/the/stdin_sample.png

Hello world image.

  • Create QR code from a text file [-f] and display the image [-d]. We do not save it this time.
    Set the scale flag [-s] to control the output image size.

$ python3 qr_code.py -f samples/sample_text.txt -d -s 4
  [+] UTF-8 encoding applied.
  [+] QR version: 30 chosen.
  [+] Error Correction Level: Q chosen.
  [+] Best mask has been applied: [2]. With 12380.0 penalty

Display sample scale 4 image.

  • Set QR code version and error correction level.

    If a message is too long to meet version [-v] and error correction level [-e] constraints, the following error will be raised.

    AssertionError: Message too long (7716) for a given version capacity (104)

    When we pass incorrect values, another error will be raised.

    qr_code.py: error: argument -v: Value out of range: 1111. Should be between 1 and 40.

    If these values are correct, then we should see the expected output image.

    $ python3 qr_code.py -i "Hello world" -d -s 5 -v 15 -e 2
    [+] Latin-1 encoding applied.
[+] QR version: 15 chosen.
[+] Error Correction Level: Q chosen.
[+] Best mask has been applied: [4]. With 3546.0 penalty

Set version ec image.

  • Setting QR code mask and quiet zone values.

It's not recommended to set a mask value [-m] if you want to be sure that the best one is chosen. It will however speed up generating QR codes noticeably. Quiet zone value [-z] determines width of white space around QR code.

  $ python3 qr_code.py -i "https://github.com/abcs-ab" -d -s 7 -v 8 -e 3 -m 3 -z 1
  [+] Latin-1 encoding applied.
  [+] QR version: 8 chosen.
  [+] Error Correction Level: H chosen.

Set mask qzone image.

  • Last but not least, the [-h] flag.

    $ python3 qr_code.py -h
    usage: qr_code.py [-h] [-v VERSION] [-e EC LEVEL] [-m MASK] [-s SCALE IMAGE]
                  [-i INPUT TEXT | -f INPUT FILE NAME] [-o OUTPUT IMAGE NAME]
                  [-z QUIET ZONE] [-d]

Create QR Code from text file [-f] or stdin [-i] and save as an image.
When version is to be chosen automatically, then it's worth noting, 
that keeping declared error correction level will be a priority.
So, qr version will be increased first, before error correction level
is lowered in order to fit a message.

optional arguments:
  -h, --help            show this help message and exit
  -v VERSION            Valid values from 1 to 40. If omitted, version is computed automatically.
  -e EC LEVEL           Valid values from 0 to 3. Default 2.
                        0 - Level L (Low)         ~7% of codewords can be restored.
                        1 - Level M (Medium)      ~15% of codewords can be restored.
                        2 - Level Q (Quartile)    ~25% of codewords can be restored.
                        3 - Level H (High)        ~30% of codewords can be restored.
  -m MASK               Valid values from 0 to 7. Default None.
  -s SCALE IMAGE        Takes positive integer. Image is resized according to this value. Default 10.
  -i INPUT TEXT         Just write anything in "quotes" and the message will be processed.
  -f INPUT FILE NAME    Text file with a message to be encoded.
  -o OUTPUT IMAGE NAME  File name for QR code output image.
  -z QUIET ZONE         Takes positive integer. It's a width of white space around QR code.
  -d                    If the flag is present, QR code preview will be displayed, when done.

Appendix

  • Kanji is handled by UTF-8 at the moment. However, straight kanji encoding would save fair number of bytes, thus longer messages would become available.

  • Please, feel free to contact me if you find a bug, typo or have some questions.

Contact

abcs.luk@gmail.com

License

MIT