I am trying to get a qrcode with opencv, in order to do this I have the following code:

import cv2
import numpy as np

...

data, bbox,rectifiedImage = qrDecoder.detectAndDecode(frame)

...

The code runs ok, but when detect the QRCode and I want get data, I got this

Library QUIRC is not linked. No decoding is performed. Take it to the OpenCV repository.

I tried with pip install quirc, but doesn't work and I installed opencv with sudo apt-get install python3-opencv.

How can I fix this?

CodePudding user response：

The version of OpenCV you get with the apt package is always fairly old. Additionally, there's no guarantee that all the modules (here: the QR decoder) were given the required dependencies (here: quirc). Installing additional packages wouldn't solve this because OpenCV needs them at build time, before packaging.

To get the most recent version, install it via pip:

$ pip3 install opencv-python

There is the opencv-python package that only contains the main modules, and there is opencv-contrib-python, which additionally contains "contrib" modules. The packages are mutually incompatible, so only install one of them.