qreader

library3.16pypypi✓ verified 86d ago

QReader is a robust and straight-forward QR code detection and decoding library for Python, powered by a YOLOv8-based QR segmentation model. It excels at reading difficult, blurry, or tricky QR codes. The current version is 3.16, with active development and frequent updates.

devops

pip install qreader

github ↗homepage ↗

INSTALL

IMPORT

SIG · QREADER

qreader

devopspythonv3.16

harness data pending

Install & Compatibility

Where this runs

No compatibility data collected yet for this library.

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

QReader

✓ from qreader import QReader

✗ import QReader

QReader is a class exported from the qreader package.

Basic usage: load an image, detect and decode QR codes, and print the result.

from qreader import QReader import cv2 # Initialize QReader qreader = QReader() # Read image image = cv2.imread('path/to/qr_code.jpg') if image is None: print('Could not load image') import sys sys.exit(1) # Detect and decode decoded_text = qreader.detect_and_decode(image=image) if decoded_text: print('Decoded text:', decoded_text) else: print('No QR code found')

Debug

Known issues

gotchaReturns empty list if no QR code is found, not None.

fix

Check if the list is empty with 'if not decoded_text' instead of 'if decoded_text is None'.

affects: >=3.0

gotchaInput image must be a numpy array (OpenCV format). QReader does not accept file paths directly.

fix

Load the image using cv2.imread() or another method to get a numpy array before passing to QReader.

affects: all

deprecatedThe 'detect_and_decode' method with argument 'img' (instead of 'image') is deprecated in version 3.0+.

fix

Use 'image' as the keyword argument instead of 'img'.

affects: >=3.0, <3.16

gotchaQReader downloads the YOLOv8 model on first use, which requires internet and may take a few seconds.

fix

Ensure internet connectivity on first run, or consider pre-downloading the model.

affects: all

Errors

Common errors & fixes

ModuleNotFoundError: No module named 'qreader'

QReader is not installed.

fix

Run 'pip install qreader'.

AttributeError: module 'qreader' has no attribute 'QReader'

Incorrect import statement.

fix

Use 'from qreader import QReader'.

TypeError: detect_and_decode() missing 1 required positional argument: 'img'

Using old API with 'img' parameter.

fix

Use 'image' instead of 'img' as the argument name.

ValueError: Could not find a QR code

No QR code detected in the image or decoding failed.

fix

Ensure the image contains a visible QR code, try different image preprocessing.

Upgrade

Version history

3.16latest on PyPI · released Feb 16, 2025

Audit

Dependencies

opencv-pythonrequiredRequired for image loading and processing.

pyzbarrequiredRequired for decoding QR codes.

ultralyticsrequiredRequired for YOLOv8 model loading and inference.

Agent activity

5 hits · last 30 days

node

Resources

githubhttps://github.com/Eric-Canas/qreader ↗

homepagehttps://github.com/Eric-Canas/qreader ↗