PyQt显示来自opencv的视频流

PyQt显示来自opencv的视频流

问题是获取图像的功能仅执行一次，而不更新标签。
正确的方法是将其放置在循环中，但会导致阻塞主窗口。主窗口的这种阻塞可以通过使用

QThread

类来解决，并通过信号发送

QImage

来更新标签。例如：

import cv2import sysfrom PyQt5.QtWidgets import  QWidget, QLabel, QApplicationfrom PyQt5.QtCore import QThread, Qt, pyqtSignal, pyqtSlotfrom PyQt5.QtGui import QImage, QPixmapclass Thread(QThread):    changePixmap = pyqtSignal(QImage)    def run(self):        cap = cv2.VideoCapture(0)        while True: ret, frame = cap.read() if ret:     # https://stackoverflow.com/a/55468544/6622587     rgbImage = cv2.cvtColor(frame, cv2.COLOR_BGR2RGB)     h, w, ch = rgbImage.shape     bytesPerLine = ch * w     convertToQtFormat = QImage(rgbImage.data, w, h, bytesPerLine, QImage.Format_RGB888)     p = convertToQtFormat.scaled(640, 480, Qt.KeepAspectRatio)     self.changePixmap.emit(p)class App(QWidget):    def __init__(self):        super().__init__()        [...]        self.initUI()    @pyqtSlot(QImage)    def setImage(self, image):        self.label.setPixmap(QPixmap.fromImage(image))    def initUI(self):        self.setWindowTitle(self.title)        self.setGeometry(self.left, self.top, self.width, self.height)        self.resize(1800, 1200)        # create a label        self.label = QLabel(self)        self.label.move(280, 120)        self.label.resize(640, 480)        th = Thread(self)        th.changePixmap.connect(self.setImage)        th.start()        self.show()