qrlyzer 0.3.3

qrlyzer is a lightweight Python module for reading QR codes from images.

qrlyzer

qrlyzer is a lightweight Python module for reading QR codes from images. It offers an optional auto-resizing feature that leverages fast_image_resize to utilize SIMD instructions for enhanced performance.

There is at least one top level domain that started using the name qrlyzer after this projects' conception and release. This project is not affiliated nor does it condone the use of the name.

Getting Started

Installing

qrlyzer is available on PyPi. Install it with:

python -m pip install qrlyzer

Basic usage:

Detecting QR codes from an image file

import qrlyzer

# From path
qr_codes = qrlyzer.detect_and_decode("my_image.jpg")
print(f"Found QR codes: {qr_codes}")

Detecting QR codes from image bytes

# From bytes
from PIL import Image
im = Image.open("my_image.jpg")
im = im.convert("L")
qr_codes = qrlyzer.detect_and_decode_from_bytes(im.to_bytes(), im.width, im.height)
print(f"Found QR codes: {qr_codes}")

Using auto-resizing

Pass the auto_resize parameter to enable automatic resizing (from 100px to 1280px in the largest direction. 5 steps). These dimensions seem to be a good detection range for the libraries used.

# Auto-scaling
qrlyzer.detect_and_decode("my_image.jpg", auto_resize=True)

Note: This can in some cases increase accuracy as well as speed, especially for large images where there is a QR code. If an image does not contain a QR code or the QR code is unreadable it will be slower.

Getting decoded text with bounding boxes (xywh)

Use the bbox variants to get both content and coordinates. The bbox format is (x, y, width, height).

results = qrlyzer.detect_and_decode_with_bbox("my_image.jpg")
for content, (x, y, width, height) in results:
    print(content, x, y, width, height)

results = qrlyzer.detect_and_decode_from_bytes_with_bbox(
    im.tobytes(), im.width, im.height
)

Uses

• maturin - Build & PyO3 bindings
• rqrr - Reading QR codes
• rxing - Reading QR codes
• fast_image_resize - Image resizing

Authors

• Nikolai Ugelvik - Initial work - NikolaiUgelvik

License

This project is licensed under the MIT License - see the LICENSE file for details

Acknowledgments

• Thanks to all the contributors to the maturin, rqrr, rxing & fast_image_resize projects.