import sysfrom PyQt5 import QtCoreimport cv2from PyQt5 import QtGuifrom PyQt5.QtCore import QThreadfrom PyQt5.QtGui import QImagefrom PyQt5.QtWidgets import QApplication, QWidget, QHBoxLayout, QLabelfrom PyQt5.QtGui import QPixmapfrom PyQt5.QtWidgets import QPushButtondef getCameraNum():    """获取摄像头数量"""    num = 0    for i in range(0,5) :        # 从摄像头中取得视频        cap = cv2.VideoCapture(i)        if cap.isOpened():            num+=1        cap.release()    return numclass FrameThread(QThread):    imgLab = None    device = None    paizhao = 0    """摄像头拍照线程，摄像头拍照耗时较长容易卡住UI"""    def __init__(self,deviceIndex,imgLab):        QThread.__init__(self)        self.imgLab = imgLab        self.deviceIndex = deviceIndex        self.device = cv2.VideoCapture(self.deviceIndex)  # 从摄像头中取得视频        self.device.set(cv2.CAP_PROP_FRAME_WIDTH, 1600)        self.device.set(cv2.CAP_PROP_FRAME_HEIGHT, 1200)    def run(self):        if self.device.isOpened():            try:                while True:                    ret, frame = self.device.read()                    height, width, bytesPerComponent = frame.shape                    bytesPerLine = bytesPerComponent * width                    # 变换彩色空间顺序                    cv2.cvtColor(frame, cv2.COLOR_BGR2RGB, frame)                    # 转为QImage对象                    image = QImage(frame.data, width, height, bytesPerLine, QImage.Format_RGB888)                    if self.paizhao == 1:                        image.save("C:\\img"+str(self.deviceIndex)+".jpg")                        self.paizhao = 0                    pixmap = QPixmap.fromImage(image)                    pixmap = pixmap.scaled(400, 300, QtCore.Qt.KeepAspectRatio)                    self.imgLab.setPixmap(pixmap)            finally:                self.device.release()        # if self.cap.isOpened():        #     # 获取视频播放界面长宽        #     width = int(self.cap.get(cv2.CAP_PROP_FRAME_WIDTH) + 0.5)        #     height = int(self.cap.get(cv2.CAP_PROP_FRAME_HEIGHT) + 0.5)        #     # 定义编码器 创建 VideoWriter 对象        #     while (self.cap.isOpened()):        #         # 读取帧摄像头        #         ret, frame = self.cap.read()        #         image = QtGui.QImage(frame, width, height, QtGui.QImage.Format_Indexed8)        #         pixmap = QtGui.QPixmap.fromImage(image.mirrored(False, True))        #         # pixmap = QPixmap('C:\left.jpg')        #         self.imgLab.setPixmap(pixmap)    def destroyed(self, QObject=None):        self.device.release()class Example(QWidget):    def __init__(self):        super().__init__()        self.initUI()    def initUI(self):        hbox = QHBoxLayout(self)        lb1 = QLabel(self)        lb2 = QLabel(self)        btn = QPushButton(self)        btn.setText("拍照")        btn.clicked.connect(self.paizhao)        self.frameThread = FrameThread(0,lb1)        self.frameThread.start()        self.frameThread2 = FrameThread(1,lb2)        self.frameThread2.start()        hbox.addWidget(lb1)        hbox.addWidget(lb2)        hbox.addWidget(btn)        self.setLayout(hbox)        self.move(300, 300)        self.setWindowTitle('像素图控件')                self.show()    def paizhao(self):        self.frameThread.paizhao = 1        self.frameThread2.paizhao = 1    def showDate(self, date):        self.lb1.setText(date.toString())if __name__ == '__main__':    app = QApplication(sys.argv)    ex = Example()    sys.exit(app.exec_())