Read image from the clipboard and decode its qr code

qrclipboard.py

#!/usr/bin/python3
from PyQt5.QtWidgets import QApplication, QLabel, QMessageBox
from pyzbar import pyzbar
import numpy as np

def qimage2mat(qimage):
    qimage.convertToFormat(4)
    ptr = qimage.bits()
    ptr.setsize(qimage.byteCount())
    arr = np.array(ptr).reshape([qimage.height(), qimage.width(), 4])
    return arr

def messagebox(text, is_error=False):
    msg = QMessageBox()
    msg.setIcon(QMessageBox.Critical if is_error else QMessageBox.Information)
    msg.setText(text)
    msg.setWindowTitle("Error" if is_error else "Information")
    msg.show()
    msg.exec_()

app = QApplication([])
clipboard = app.clipboard()
qimage = clipboard.image()
if not qimage.bits():
    messagebox("No image in clipboard", True)
    exit(1)
img = qimage2mat(qimage)
qrs = pyzbar.decode(img)
if qrs:
    texts = [qr.data.decode() for qr in qrs]
    clipboard.setText(texts[0])
    messagebox("\n".join(texts) + "\nCopied to clipboard")
else:
    messagebox("No QR code found", True)
    exit(1)