QR code and Micro QR code serialization¶

A QR code or Micro QR code is independent of its output, it’s just a matrix. To save a QR code or Micro QR code, Segno provides several output formats.

Segno provides a segno.QRCode.save() method to serialize a (Micro) QR code in different formats:

>>> import segno
>>> qrcode = segno.make('Tomorrow Never Knows')
>>> qrcode.save('tomorrow-never-knows.svg')
>>> qrcode.save('tomorrow-never-knows.png')
>>> qrcode.save('tomorrow-never-knows.eps')

2-Q QR code encoding "Tomorrow Never Knows"

Border¶

All serializers accept a border parameter which indicates the “quiet zone” of a (Micro) QR code. If border is None, the default border (quiet zone) size will be used. If the resulting (Micro) QR code should have no border or a custom border, the user may specify the border explicitly.

>>> import segno
>>> qrcode = segno.make('Vampire Blues')
>>> qrcode.save('vampire-blues.svg', border=0)  # No border

>>> import segno
>>> qrcode = segno.make('Vampire Blues')
>>> qrcode.save('vampire-blues.png', border=10)  # Larger border

M4-M QR code encoding "Vampire Blues", quiet zone of 10

Scale¶

Most serializers accept a scale parameter which indicates the scaling factor of the serialization. By default, the scaling factor is 1 which means that size of a dark / light module is interpreted as one unit in the specific user space (i.e. 1 pixel for the PNG serializer or 1 point (1/72 of an inch) in EPS). Some serializers (like PNG) accept only an integer value or convert the provided scaling factor to an integer. Other, like SVG and EPS, accept float values and do not “downgrade” it to an integer.

>>> import segno
>>> qrcode = segno.make_qr('The Beatles')
>>> qrcode.save('the-beatles.png', scale=1.2)  # No scaling at all since int(1.2) is 1

>>> import segno
>>> qrcode = segno.make_qr('The Beatles')
>>> qrcode.save('the-beatles.png', scale=10)  # 1 module == 10 pixels

>>> import segno
>>> qrcode = segno.make_qr('The Beatles')
>>> qrcode.save('the-beatles.svg', scale=2.4)  # SVG accepts float values

>>> import segno
>>> qrcode = segno.make_qr('The Beatles')
>>> # The SVG serializer provides the "unit" parameter to specify
>>> # how to interpret the values
>>> qrcode.save('the-beatles.svg', scale=10, unit='mm')  # 1 unit = 1 mm

>>> import segno
>>> qrcode = segno.make_qr('The Beatles')
>>> qrcode.save('the-beatles.svg', unit='cm')  # 1 unit = 1 cm, result as above

Color of dark and light modules¶

Many serializers accept the parameters dark and light to specify the color of the dark modules and light modules. See Colorful QR Codes for details.

>>> import segno
>>> qrcode = segno.make("Sgt. Pepper’s Lonely Hearts Club Band")
>>> qrcode.save('sgt-peppers.svg', dark='darkred', light='lightblue')

>>> import segno
>>> qrcode = segno.make("Sgt. Pepper’s Lonely Hearts Club Band")
>>> qrcode.save('sgt-peppers.svg', dark='#ccc')

>>> import segno
>>> qrcode = segno.make("Sgt. Pepper’s Lonely Hearts Club Band")
>>> qrcode.save('sgt-peppers.png', light=None)  # Transparent background

3-M QR code encoding "Sgt. Pepper’s Lonely Hearts Club Band"

>>> import segno
>>> qrcode = segno.make("Sgt. Pepper’s Lonely Hearts Club Band")
>>> # Dark modules = transparent, light modules = black
>>> qrcode.save('sgt-peppers.png', dark=None, light='black')

>>> import segno
>>> qrcode = segno.make("Sgt. Pepper’s Lonely Hearts Club Band")
>>> # Dark modules with alpha transparency
>>> qrcode.save('sgt-peppers.png', dark='#0000ffcc')

>>> import segno
>>> qrcode = segno.make("Sgt. Pepper’s Lonely Hearts Club Band")
>>> qrcode.save('sgt-peppers.svg', dark='#00fc')  # Same as above but SVG

>>> import segno
>>> qrcode = segno.make("Sgt. Pepper’s Lonely Hearts Club Band")
>>> # Anonther color, save as compressed SVG
>>> qrcode.save('sgt-peppers.svgz', dark=(8, 90, 117))

Saving QR codes to streams¶

If the QR code should be serialized to a buffer, use the kind parameter to specify the output format. Please note that some serializers write bytes while others write strings, see segno.QRCode.save() for details.

>>> import segno
>>> import io
>>> qrcode = segno.make('Paul McCartney')
>>> buff = io.BytesIO()
>>> qrcode.save(buff, kind='svg')
>>> # All other serializer parameters are supported as well
>>> buff = io.BytesIO()
>>> qrcode.save(buff, kind='svg', dark='darkblue', light='#eee')

See segno.QRCode.save() for a complete reference which parameters are accepted by the specific serializer.

More colorful QR Codes¶

The SVG, PNG and PPM serializers support more than two colors.

>>> import segno
>>> qrcode = segno.make('Yellow Submarine', version=7, error='h')
>>> qrcode.save('qrcode_yellow-submarine.png', scale=5, dark='darkred',
...             data_dark='darkorange', data_light='yellow')

Colorful 7-H QR code encoding "Yellow Submarine"

See Colorful QR Codes for available options.

Available serializers¶

ANSI: ANSI escape code. The serializer supports the border keyword, only. See ANSI for details.
EPS: Encapsulated PostScript (EPS). The serializer provides all default features (scale, border, color of dark / light modules), see EPS for details.
LaTeX: LaTeX / PGF/TikZ. The serializer provides no support to change the color of the light modules, but all other default features (scale, border, color) are supported, see LaTeX for details.
PAM: Portable Arbitrary Map (PAM). The serializer provides all default features (scale, border, color of dark / light modules), see PAM for details.
PBM: Portable Bitmap (PBM). The serializer does not support any coloring, but the common featurs like scale and border are supported, see PBM for details.
PPM: Portable Pixmap (PPM). The serializer does not support transparency, but the common features like scale, border and (multiple) colors are supported, see PPM for details.
PDF: Portable Document Format (PDF). The serializer provides all default features (scale, border, color of dark / light modules), see PDF for details.
PNG: Portable Network Graphics (PNG). The serializer provides all default features (scale, border, color of dark / light modules) and a few more to customize the output, see PNG for details.
SVG: Scalable Vector Graphics (SVG). The serializer provides all default features (scale, border, color of dark / light modules) and many more to customize the output, see SVG for details. SVGZ (compressed SVG) is supported as well.
TXT: Text output. The serializer does not support any scale or color, but the characters for the dark and light modules may be specified, see TXT for details.
XBM: X BitMap (XBM). The serializer does not support any coloring, but scale and border are supported, see XBM for details.
XPM: X PixMap (XPM). The serializer provides all default features (scale, border, color of dark / light modules) and a few more, see XPM for details.