Read one-dimensional barcodes and QR codes from Python 2 and 3.
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Read one-dimensional barcodes and QR codes from Python 2 and 3 using the
zbar <http://zbar.sourceforge.net/>
__ library.
ndarray
\ s, and raw bytesThe older zbar <https://sourceforge.net/p/zbar/code/ci/default/tree/python/>
__
package is stuck in Python 2.x-land.
The zbarlight <https://github.com/Polyconseil/zbarlight/>
__ package does not
provide support for Windows and depends upon Pillow.
The zbar
DLLs are included with the Windows Python wheels.
On other operating systems, you will need to install the zbar
shared
library.
Mac OS X:
::
brew install zbar
Linux:
::
sudo apt-get install libzbar0
Install this Python wrapper; use the second form to install dependencies of the command-line scripts:
::
pip install pyzbar pip install pyzbar[scripts]
The decode
function accepts instances of PIL.Image
.
::
from pyzbar.pyzbar import decode from PIL import Image decode(Image.open('pyzbar/tests/code128.png')) [ Decoded( data=b'Foramenifera', type='CODE128', rect=Rect(left=37, top=550, width=324, height=76), polygon=[ Point(x=37, y=551), Point(x=37, y=625), Point(x=361, y=626), Point(x=361, y=550) ], orientation="UP", quality=77 ) Decoded( data=b'Rana temporaria', type='CODE128', rect=Rect(left=4, top=0, width=390, height=76), polygon=[ Point(x=4, y=1), Point(x=4, y=75), Point(x=394, y=76), Point(x=394, y=0) ], orientation="UP", quality=77 ) ]
It also accepts instances of numpy.ndarray
, which might come from loading
images using OpenCV <http://opencv.org/>
__.
::
import cv2 decode(cv2.imread('pyzbar/tests/code128.png')) [ Decoded( data=b'Foramenifera', type='CODE128', rect=Rect(left=37, top=550, width=324, height=76), polygon=[ Point(x=37, y=551), Point(x=37, y=625), Point(x=361, y=626), Point(x=361, y=550) ], orientation="UP", quality=77 ) Decoded( data=b'Rana temporaria', type='CODE128', rect=Rect(left=4, top=0, width=390, height=76), polygon=[ Point(x=4, y=1), Point(x=4, y=75), Point(x=394, y=76), Point(x=394, y=0) ], orientation="UP", quality=77 ) ]
You can also provide a tuple (pixels, width, height)
, where the image data
is eight bits-per-pixel.
::
image = cv2.imread('pyzbar/tests/code128.png') height, width = image.shape[:2]
8 bpp by considering just the blue channel
decode((image[:, :, 0].astype('uint8').tobytes(), width, height)) [ Decoded( data=b'Foramenifera', type='CODE128', rect=Rect(left=37, top=550, width=324, height=76), polygon=[ Point(x=37, y=551), Point(x=37, y=625), Point(x=361, y=626), Point(x=361, y=550) ], orientation="UP", quality=77 ) Decoded( data=b'Rana temporaria', type='CODE128', rect=Rect(left=4, top=0, width=390, height=76), polygon=[ Point(x=4, y=1), Point(x=4, y=75), Point(x=394, y=76), Point(x=394, y=0) ], orientation="UP", quality=77 ) ]
8 bpp by converting image to greyscale
grey = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY) decode((grey.tobytes(), width, height)) [ Decoded( data=b'Foramenifera', type='CODE128', rect=Rect(left=37, top=550, width=324, height=76), polygon=[ Point(x=37, y=551), Point(x=37, y=625), Point(x=361, y=626), Point(x=361, y=550) ], orientation="UP", quality=77 ) Decoded( data=b'Rana temporaria', type='CODE128', rect=Rect(left=4, top=0, width=390, height=76), polygon=[ Point(x=4, y=1), Point(x=4, y=75), Point(x=394, y=76), Point(x=394, y=0) ], orientation="UP", quality=77 ) ]
If you don't provide 8 bpp
decode((image.tobytes(), width, height)) Traceback (most recent call last): File "
", line 1, in File "/Users/lawh/projects/pyzbar/pyzbar/pyzbar.py", line 102, in decode raise PyZbarError('Unsupported bits-per-pixel [{0}]'.format(bpp)) pyzbar.pyzbar_error.PyZbarError: Unsupported bits-per-pixel [24]
The default behaviour is to decode all symbol types. You can look for just your symbol types
::
from pyzbar.pyzbar import ZBarSymbol
Look for just qrcode
decode(Image.open('pyzbar/tests/qrcode.png'), symbols=[ZBarSymbol.QRCODE]) [ Decoded( data=b'Thalassiodracon', type='QRCODE', rect=Rect(left=27, top=27, width=145, height=145), polygon=[ Point(x=27, y=27), Point(x=27, y=172), Point(x=172, y=172), Point(x=172, y=27) ], orientation="UP", quality=1 ) ]
If we look for just code128, the qrcodes in the image will not be detected
decode(Image.open('pyzbar/tests/qrcode.png'), symbols=[ZBarSymbol.CODE128]) []
Development of the original zbar <http://zbar.sourceforge.net/>
__ stopped in 2012.
Development was started again in 2019 under a new project <https://github.com/mchehab/zbar/>
__
that has added some new features, including support for decoding
barcode orientation. At the time of writing this new project does not produce Windows DLLs.
The zbar
DLLs that are included with the Windows Python wheels are built from the original
project and so do not include support for decoding barcode orientation.
If you see orientation=None
then your system has an older release of zbar that does
not support orientation.
From
zbar.h <https://sourceforge.net/p/zbar/code/ci/default/tree/include/zbar.h#l359>
__, the quality field is
...an unscaled, relative quantity: larger values are better than smaller values, where "large" and "small" are application dependent. Expect the exact definition of this quantity to change as the metric is refined. currently, only the ordered relationship between two values is defined and will remain stable in the future
The blue and pink boxes show rect
and polygon
, respectively, for
barcodes in pyzbar/tests/qrcode.png
(see
bounding_box_and_polygon.py <https://github.com/NaturalHistoryMuseum/pyzbar/blob/master/bounding_box_and_polygon.py>
__).
.. figure:: https://github.com/NaturalHistoryMuseum/pyzbar/raw/master/bounding_box_and_polygon.png :alt: Two barcodes with bounding boxes and polygons
If you see an ugly ImportError
when importing pyzbar
on Windows
you will most likely need the Visual C++ Redistributable Packages for Visual Studio 2013 <https://www.microsoft.com/en-US/download/details.aspx?id=40784>
__.
Install vcredist_x64.exe
if using 64-bit Python, vcredist_x86.exe
if
using 32-bit Python.
pyzbar
is distributed under the MIT license (see LICENCE.txt
).
The zbar
shared library is distributed under the
GNU Lesser General Public License, version 2.1 <http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html>
__