TL;DR: I need a way to decode a QR-code from an image file using (preferable pure) Python.
I've got a jpg file with a QR-code which I want to decode using Python. I've found a couple libraries which claim to do this:
PyQRCode (website here) which supposedly can decode qr codes from images by simply providing a path like this:
import sys, qrcode
d = qrcode.Decoder()
if d.decode('out.png'):
print 'result: ' + d.result
else:
print 'error: ' + d.error
So I simply installed it using sudo pip install pyqrcode
. The thing I find strange about the example code above however, is that it only imports qrcode
(and not pyqrcode
though) Since I think qrcode
refers to this library which can only generate qr-code images it kind of confused me. So I tried the code above with both pyqrcode
and qrcode
, but both fail at the second line saying AttributeError: 'module' object has no attribute 'Decoder'
. Furthermore, the website refers to Ubuntu 8.10 (which came out more than 6 years ago) and I can't find a public (git or other) repository of it to check the latest commit. So I moved on to the next library:
ZBar (website here) claims to be "an open source software suite for reading bar codes from various sources, such as image files."
So I tried installing it on Mac OSX running sudo pip install zbar
. This fails with error: command 'cc' failed with exit status 1
. I tried to suggestions in the answers to this SO question, but I can't seem to solve it. So I decided to move on again:
QRTools, which according to this blogpost can decode images easily by using the following code:
from qrtools import QR
myCode = QR(filename=u"/home/psutton/Documents/Python/qrcodes/qrcode.png")
if myCode.decode():
print myCode.data
print myCode.data_type
print myCode.data_to_string()
So I tried installing it using sudo pip install qrtools
, which can't find anything. I also tried it with python-qrtools
, qr-tools
, python-qrtools
and a couple more combinations, but unfortunately to no avail. I suppose it refers to this repo which says it is based on ZBar (see above). Although I want to run my code on Heroku (and thus prefer a pure Python solution) I successfully installed it on a Linux box (with sudo apt-get install python-qrtools
) and tried running it:
from qrtools import QR
c = QR(filename='/home/kramer65/qrcode.jpg')
c.data # prints u'NULL'
c.data_type # prints u'text'
c.data_to_string() # prints '\xef\xbb\xbfNULL' where I expect an int (being `1234567890`)
Although this seems to decode it, It doesn't seem to do it correctly. It furthermore needs ZBar and is thus not pure Python. So I decided to find yet another library.
PyXing (website here) is supposedly a Python port of the popular Java ZXing library, but the initial and only commit is 6 years old and the project has no readme or documentation whatsoever.
For the rest I found a couple qr-encoders (not decoders) and some API endpoints which can decode for you. Since I don't like this service to be dependent on other API endpoints I would want to keep the decoding local though.
So to conclude; would anybody know how I can decode QR-codes from images in (preferable pure) Python? All tips are welcome!
The following code works fine with me:
brew install zbar
pip install pyqrcode
pip install pyzbar
For QR code image creation:
import pyqrcode
qr = pyqrcode.create("test1")
qr.png("test1.png", scale=6)
For QR code decoding:
from PIL import Image
from pyzbar.pyzbar import decode
data = decode(Image.open('test1.png'))
print(data)
that prints the result:
[Decoded(data=b'test1', type='QRCODE', rect=Rect(left=24, top=24, width=126, height=126), polygon=[Point(x=24, y=24), Point(x=24, y=150), Point(x=150, y=150), Point(x=150, y=24)])]
There is a library called BoofCV which claims to better than ZBar and other libraries.
Here are the steps to use that (any OS).
Pre-requisites:
pip install pyboof
Class to decode:
import os
import numpy as np
import pyboof as pb
pb.init_memmap() #Optional
class QR_Extractor:
# Src: github.com/lessthanoptimal/PyBoof/blob/master/examples/qrcode_detect.py
def __init__(self):
self.detector = pb.FactoryFiducial(np.uint8).qrcode()
def extract(self, img_path):
if not os.path.isfile(img_path):
print('File not found:', img_path)
return None
image = pb.load_single_band(img_path, np.uint8)
self.detector.detect(image)
qr_codes = []
for qr in self.detector.detections:
qr_codes.append({
'text': qr.message,
'points': qr.bounds.convert_tuple()
})
return qr_codes
Usage:
qr_scanner = QR_Extractor()
output = qr_scanner.extract('Your-Image.jpg')
print(output)
Tested and works on Python 3.8 (Windows & Ubuntu)
ZBar
Pre-requisites:
choco install zbar
pip install pyzbar
To decode:
from PIL import Image
from pyzbar import pyzbar
img = Image.open('My-Image.jpg')
output = pyzbar.decode(img)
print(output)
Alternatively, you can also try using ZBarLight
by setting it up as mentioned here:
https://pypi.org/project/zbarlight/
I'm answering only the part of the question about zbar
installation.
I spent nearly half an hour a few hours to make it work on Windows + Python 2.7 64-bit, so here are additional notes to the accepted answer:
Install it with pip install zbar-0.10-cp27-none-win_amd64.whl
If Python reports an ImportError: DLL load failed: The specified module could not be found.
when doing import zbar
, then you will just need to install the Visual C++ Redistributable Packages for VS 2013 (I spent a lot of time here, trying to recompile unsuccessfully...)
Required too: libzbar64-0.dll must be in a folder which is in the PATH. In my case I copied it to "C:\Python27\libzbar64-0.dll" (which is in the PATH). If it still does not work, add this:
import os
os.environ['PATH'] += ';C:\\Python27'
import zbar
PS: Making it work with Python 3.x is even more difficult: Compile zbar for Python 3.x.
PS2: I just tested pyzbar with pip install pyzbar
and it's MUCH easier, it works out-of-the-box (the only thing is you need to have VC Redist 2013 files installed). It is also recommended to use this library in this pyimagesearch.com article.
Source: Stackoverflow.com