Qt Python으로 문서 스캔 및 바코드 인식 애플리케이션 구축

전제 조건

pip install dbr

pip install PyQt5

크로스 플랫폼 문서 스캐닝 및 바코드 인식 애플리케이션 구축 단계

1. Qt 위젯으로 Qt 애플리케이션 만들기

from PyQt5.QtWidgets import *
from PyQt5.QtCore import *
from PyQt5.QtGui import *
from PyQt5.QtWebEngineWidgets import QWebEngineView
from PyQt5.QtWebChannel import QWebChannel

app = QApplication([])
win = QWidget()
win.setWindowTitle('Dynamic Web TWAIN and Dynamsoft Barcode Reader')
win.show()
app.exec_()

class WebView(QWebEngineView):
    def __init__(self):
        QWebEngineView.__init__(self)

layout = QVBoxLayout()
win.setLayout(layout)

view = WebView()
bt_scan = QPushButton('Scan Barcode Documents')
bt_read = QPushButton('Read Barcode')
text_area = QTextEdit()

layout.addWidget(view)
layout.addWidget(bt_scan)
layout.addWidget(bt_read)
layout.addWidget(text_area)

def keyPressEvent(event):
    if event.key() == Qt.Key.Key_Q:
        win.close()
    elif event.key() == Qt.Key.Key_R:
        refresh_page()

win.keyPressEvent = keyPressEvent

python app.py

2. Qt 애플리케이션에서 HTML 및 JavaScript 코드 로드

import os

class WebView(QWebEngineView):
    def __init__(self):
        QWebEngineView.__init__(self)

        # Load web page and resource files to QWebEngineView
        file_path = os.path.abspath(os.path.join(
            os.path.dirname(__file__), "index.html"))
        local_url = QUrl.fromLocalFile(file_path)
        self.load(local_url)

3. Python과 JavaScript 간의 통신 설정

function AcquireImage() {
    if (DWObject) {
        var OnAcquireImageSuccess, OnAcquireImageFailure;
        OnAcquireImageSuccess = OnAcquireImageFailure = function () {
            DWObject.CloseSource();
        };

        DWObject.SelectSourceByIndex(document.getElementById("source").selectedIndex); //Use method SelectSourceByIndex to avoid the 'Select Source' dialog
        DWObject.OpenSource();
        DWObject.IfDisableSourceAfterAcquire = true;    // Scanner source will be disabled/closed automatically after the scan.
        DWObject.AcquireImage(OnAcquireImageSuccess, OnAcquireImageFailure);
    }
}

def read_barcode():
    frame = view.page()
    frame.runJavaScript('AcquireImage();')

bt_scan.clicked.connect(acquire_image)

function getCurrentImage() {
    if (DWObject) {
        DWObject.ConvertToBase64(
            [DWObject.CurrentImageIndexInBuffer],
            Dynamsoft.DWT.EnumDWT_ImageType.IT_JPG,
            function (result, indices, type) {
                // TODO:
            },
            function (errorCode, errorString) {
                console.log(errorString);
            }
        );
    }
}

var backend;
new QWebChannel(qt.webChannelTransport, function (channel) {
    backend = channel.objects.backend;
});

function getCurrentImage() {
    if (DWObject) {
        DWObject.ConvertToBase64(
            [DWObject.CurrentImageIndexInBuffer],
            Dynamsoft.DWT.EnumDWT_ImageType.IT_JPG,
            function (result, indices, type) {
                backend.onDataReady(result.getData(0, result.getLength()))
            },
            function (errorCode, errorString) {
                console.log(errorString);
            }
        );
    }
}

class Backend(QObject):
    @pyqtSlot(str)
    def onDataReady(self, base64img):

class WebView(QWebEngineView):
    def __init__(self):
        QWebEngineView.__init__(self)

        # Load web page and resource files to QWebEngineView
        file_path = os.path.abspath(os.path.join(
            os.path.dirname(__file__), "index.html"))
        local_url = QUrl.fromLocalFile(file_path)
        self.load(local_url)
        self.backend = Backend(self)
        self.channel = QWebChannel(self.page())
        self.channel.registerObject('backend', self.backend)
        self.page().setWebChannel(self.channel)

def read_barcode():
    frame = view.page()
    frame.runJavaScript('getCurrentImage();')

bt_read.clicked.connect(read_barcode)

4. 스캔한 문서에서 바코드 디코딩

from dbr import *
import base64

# Initialize Dynamsoft Barcode Reader
reader = BarcodeReader()
# Apply for a trial license https://www.dynamsoft.com/customer/license/trialLicense?product=dbr
reader.init_license('LICENSE-KEY')

class Backend(QObject):
    @pyqtSlot(str)
    def onDataReady(self, base64img):
        imgdata = base64.b64decode(base64img)

        try:
            text_results = reader.decode_file_stream(bytearray(imgdata), '')
            if text_results != None:
                out = ''
                for text_result in text_results:
                    out += "Barcode Format : "
                    out += text_result.barcode_format_string + '\n'
                    out += "Barcode Text : "
                    out += text_result.barcode_text + '\n'
                    out += "-------------------------------------------------" + '\n'

                text_area.setText(out)
        except BarcodeReaderError as bre:
            print(bre)

소스 코드