2）相机视频流停止预览；

3）相机拍照功能。

需求背景 ：客户需要对生产的产品进行定期抽样质检，其中涉及到外观检测，比如，样品的表面清洁度、外观等指标。所以，需要先通过管理平台点击相机的“预览”按钮，进行预览相机拍摄的实时效果，当客户认为清晰度和角度满足条件时，才会点击“拍照”按钮进行拍摄，从而保证质检的照片是有意义和有实用价值的。

二、调研历程

由于项目团队同事之前没有做过工业相机视频和拍照的相关开发，于是乎，就开启了“漫长”而“煎熬”的调研之路（断断续续持续了1个多月）。

最终于2022年12月6日，通过 Python “完美”实现了上述的三个功能。

特地写下此篇博客，供需要的网友参考，避免少走很多弯路。

1、海康工业相机官网

https://www.hikrobotics.com/cn/machinevision/productdetail?id=8518&pageNumber=13&pageSize=20

2、官网示例

可以在海康机器人官网提供的 客户端工具 MVS，“ 帮助 ”--> " Development "，点击“Development”会跳转到安装目录，从“Samples”中获取官方提供的一些简单示例。

如果已经安装了 MVS，直接进入 C:\Program Files (x86)\MVS\Development\Samples 目录即可看到，目前支持 C#、C++、 Java 、OpenCV、 Python 、VB等语言。

本人主要使用Java和Python，所以，本篇博文主要从Java和Python两种语言调研了实现方案。

1）RTSP（Runtime Stream Protocol）协议方向

（ 很遗憾， 此路不通！！！ ）

因为我们用的 海康机器人工业相机 MV-CU060-10GM 这款相机 ， 不支持 RTSP 协议 。

如下博客适用于 海康威视摄像头 ， 并不适用于 海康工业相机 ，如果是使用海康威视摄像头的小伙伴可以参考下。

参考博客： 海康威视摄像头对接SDK实时预览功能和抓拍功能，懒癌福利，可直接CV

2）Java实现方向

（ 不能完全满足客户需求， 此路不全通 ）

使用Java目前参考官网的示例，实现了图片抓取，并上传的功能，但是没有实现视频流的实时获取和显示的功能。

如果需求只是获取图片，不要求视频流实时显示，可以通过Java就可以实现。

3）Python实现方向

（ 目前，网上没有直接能完全满足上述三个需求的，本人通过借鉴、整合，结合Flask框架实现的 ）

参考博客如下：

python语言下使用opencv接口cv2.VideoCapture()接口调用海康机器人工业相机 （ 此篇博文可以重点看！！！ ）

通过python调用海康威视工业摄像头并进行图像存储，同时使用opencv实时图像显示（数据流问题已解决）

python调用海康工业相机并用opencv显示（整体实现） （ 此篇博文可以重点看！！！ ）

pyQT5 学习使用 笔记 六 pyQt5+opencv 显示海康GIGE相机动态视频流 ( 该方式虽然实现了视频的实时显示，但是，无法被给前端直接调用 )

web实时显示摄像头图像（python） （ 此篇博文可以重点看！！！ ）

4）Flask 的相关教程和博客

https://www.w3cschool.cn/flask/
https://dormousehole.readthedocs.io/en/latest/
https://blog.csdn.net/weixin_44239541/article/details/89390139
https://zhuanlan.zhihu.com/p/104273184
https://blog.csdn.net/tulan_xiaoxin/article/details/79132214

三、Python 代码实现

1、Python 环境

1）Python 版本

个人使用的是 Python 3.8.5 版本（ 建议使用该版本或者更高版本 ）

Python 官网地址： https://www.python.org/

安装和配置可以参考： https://www.runoob.com/python3/python3-install.html

2）Python 虚拟环境

个人建议给该工程单独创建一个Python虚拟环境（如：hikrobotEnv），后续现场如果出现无法连接外网的情况下，可以直接Copy虚拟环境部署，比较方便。

当然，如果不是特殊情况，多个项目工程可以共用一个虚拟环境。

可以使用 virtualenv、anaconda、PyCharm 等创建虚拟环境。

以 virtualenv 为例，创建 hikrobotEnv 虚拟环境的命令如下：

virtualenv hikrobotEnv --python=python3.8.5 

如果没有安装 virtualenv，可以通过如下命令安装：

pip install virtualenv

关于 virtualenv 的相关介绍和使用，可以参考博客： Python虚拟环境Virtualenv详解

2、测试代码

1）抓取图片测试代码

前提条件 ：将 C:\Program Files (x86)\MVS\Development\Samples\Python\ 目录下的 MvImport 目录，copy到自己的工程目录下，创建测试文件 TestGrabImage.py

代码如下：

# -- coding: utf-8 --
import cv2
import sys
import copy
import msvcrt
import numpy as np
from ctypes import *
sys.path.append("./MvImport")
from MvCameraControl_class import *
if __name__ == "__main__":
    deviceList = MV_CC_DEVICE_INFO_LIST()
    tlayerType = MV_GIGE_DEVICE | MV_USB_DEVICE
    # ch:枚举设备 | en:Enum device
    ret = MvCamera.MV_CC_EnumDevices(tlayerType, deviceList)
    if ret != 0:
        print ("enum devices fail! ret[0x%x]" % ret)
        sys.exit()
    if deviceList.nDeviceNum == 0:
        print ("find no device!")
        sys.exit()
    print ("find %d devices!" % deviceList.nDeviceNum)
    for i in range(0, deviceList.nDeviceNum):
        mvcc_dev_info = cast(deviceList.pDeviceInfo[i], POINTER(MV_CC_DEVICE_INFO)).contents
        if mvcc_dev_info.nTLayerType == MV_GIGE_DEVICE:
            print ("\ngige device: [%d]" % i)
            strModeName = ""
            for per in mvcc_dev_info.SpecialInfo.stGigEInfo.chModelName:
                strModeName = strModeName + chr(per)
            print ("device model name: %s" % strModeName)
            nip1 = ((mvcc_dev_info.SpecialInfo.stGigEInfo.nCurrentIp & 0xff000000) >> 24)
            nip2 = ((mvcc_dev_info.SpecialInfo.stGigEInfo.nCurrentIp & 0x00ff0000) >> 16)
            nip3 = ((mvcc_dev_info.SpecialInfo.stGigEInfo.nCurrentIp & 0x0000ff00) >> 8)
            nip4 = (mvcc_dev_info.SpecialInfo.stGigEInfo.nCurrentIp & 0x000000ff)
            print ("current ip: %d.%d.%d.%d\n" % (nip1, nip2, nip3, nip4))
        elif mvcc_dev_info.nTLayerType == MV_USB_DEVICE:
            print ("\nu3v device: [%d]" % i)
            strModeName = ""
            for per in mvcc_dev_info.SpecialInfo.stUsb3VInfo.chModelName:
                if per == 0:
                    break
                strModeName = strModeName + chr(per)
            print ("device model name: %s" % strModeName)
            strSerialNumber = ""
            for per in mvcc_dev_info.SpecialInfo.stUsb3VInfo.chSerialNumber:
                if per == 0:
                    break
                strSerialNumber = strSerialNumber + chr(per)
            print ("user serial number: %s" % strSerialNumber)
    nConnectionNum = 0
    if int(nConnectionNum) >= deviceList.nDeviceNum:
        print ("intput error!")
        sys.exit()
    # ch:创建相机实例 | en:Creat Camera Object
    cam = MvCamera()
    # ch:选择设备并创建句柄 | en:Select device and create handle
    stDeviceList = cast(deviceList.pDeviceInfo[int(nConnectionNum)], POINTER(MV_CC_DEVICE_INFO)).contents
    ret = cam.MV_CC_CreateHandle(stDeviceList)
    if ret != 0:
        print ("create handle fail! ret[0x%x]" % ret)
        sys.exit()
    # ch:打开设备 | en:Open device
    ret = cam.MV_CC_OpenDevice(MV_ACCESS_Exclusive, 0)
    if ret != 0:
        print ("open device fail! ret[0x%x]" % ret)
        sys.exit()
    # ch:探测网络最佳包大小(只对GigE相机有效) | en:Detection network optimal package size(It only works for the GigE camera)
    if stDeviceList.nTLayerType == MV_GIGE_DEVICE:
        nPacketSize = cam.MV_CC_GetOptimalPacketSize()
        if int(nPacketSize) > 0:
            ret = cam.MV_CC_SetIntValue("GevSCPSPacketSize", nPacketSize)
            if ret != 0:
                print ("Warning: Set Packet Size fail! ret[0x%x]" % ret)
        else:
            print ("Warning: Get Packet Size fail! ret[0x%x]" % nPacketSize)
    # ch:设置触发模式为off | en:Set trigger mode as off
    ret = cam.MV_CC_SetEnumValue("TriggerMode", MV_TRIGGER_MODE_OFF)
    if ret != 0:
        print ("set trigger mode fail! ret[0x%x]" % ret)
        sys.exit()
    # ch:获取数据包大小 | en:Get payload size
    stParam = MVCC_INTVALUE()
    memset(byref(stParam), 0, sizeof(MVCC_INTVALUE))
    ret = cam.MV_CC_GetIntValue("PayloadSize", stParam)
    if ret != 0:
        print ("get payload size fail! ret[0x%x]" % ret)
        sys.exit()
    nPayloadSize = stParam.nCurValue
    # ch:开始取流 | en:Start grab image
    ret = cam.MV_CC_StartGrabbing()
    if ret != 0:
        print ("start grabbing fail! ret[0x%x]" % ret)
        sys.exit()
    stDeviceList = MV_FRAME_OUT_INFO_EX()
    memset(byref(stDeviceList), 0, sizeof(stDeviceList))
    data_buf = (c_ubyte * nPayloadSize)()
    ret = cam.MV_CC_GetOneFrameTimeout(byref(data_buf), nPayloadSize, stDeviceList, 1000)
    if ret == 0:
        print ("get one frame: Width[%d], Height[%d], nFrameNum[%d]" % (stDeviceList.nWidth, stDeviceList.nHeight, stDeviceList.nFrameNum))
        nRGBSize = stDeviceList.nWidth * stDeviceList.nHeight * 3
        stConvertParam=MV_SAVE_IMAGE_PARAM_EX()
        stConvertParam.nWidth = stDeviceList.nWidth
        stConvertParam.nHeight = stDeviceList.nHeight
        stConvertParam.pData = data_buf
        stConvertParam.nDataLen = stDeviceList.nFrameLen
        stConvertParam.enPixelType = stDeviceList.enPixelType
        stConvertParam.nImageLen = stConvertParam.nDataLen
        stConvertParam.nJpgQuality = 70
        stConvertParam.enImageType = MV_Image_Jpeg
        stConvertParam.pImageBuffer = (c_ubyte * nRGBSize)()
        stConvertParam.nBufferSize = nRGBSize
        # ret = cam.MV_CC_ConvertPixelType(stConvertParam)
        print(stConvertParam.nImageLen)
        ret = cam.MV_CC_SaveImageEx2(stConvertParam)
        if ret != 0:
            print ("convert pixel fail ! ret[0x%x]" % ret)
            del data_buf
            sys.exit()
        file_path = "AfterConvert_RGB2.jpg"
        file_open = open(file_path.encode('ascii'), 'wb+')
        img_buff = (c_ubyte * stConvertParam.nImageLen)()
        cdll.msvcrt.memcpy(byref(img_buff), stConvertParam.pImageBuffer, stConvertParam.nImageLen)
        file_open.write(img_buff)
    print ("Save Image succeed!")
    # ch:停止取流 | en:Stop grab image
    ret = cam.MV_CC_StopGrabbing()
    if ret != 0:
        print ("stop grabbing fail! ret[0x%x]" % ret)
        del data_buf
        sys.exit()
    # ch:关闭设备 | Close device
    ret = cam.MV_CC_CloseDevice()
    if ret != 0:
        print ("close deivce fail! ret[0x%x]" % ret)
        del data_buf
        sys.exit()
    # ch:销毁句柄 | Destroy handle
    ret = cam.MV_CC_DestroyHandle()
    if ret != 0:
        print ("destroy handle fail! ret[0x%x]" % ret)
        del data_buf
        sys.exit()
    del data_buf

在python 虚拟环境中，执行 python TestGrabImage.py 运行后，会在当前目录下生成一个名为 AfterConvert_RGB2.jpg 的图片文件。

如果运行过程中提示模块不存在，可以通过 pip install 命令安装相应的模块，建议使用 清华源 ，如 安装 opencv-python ，命令如下：

pip install opencv-python==4.1.2.30 -i https://pypi.tuna.tsinghua.edu.cn/simple

2）Python+Qt 实现视频流实时显示测试代码

前提条件 ：将 C:\Program Files (x86)\MVS\Development\Samples\Python\ 目录下的 MvImport 目录，copy到自己的工程目录下，创建测试文件 TestVideoStream.py

代码如下：

# -- coding: utf-8 --
import cv2
from PyQt5 import QtCore, QtGui, QtWidgets
from PyQt5.QtCore import pyqtSignal
from PyQt5.QtGui import *
import numpy as np
#from CameraControl_header import MV_CC_DEVICE_INFO_LIST
#from mainWindow import Ui_MainWindow  # 导入创建的GUI类
import sys
import threading
import msvcrt
from ctypes import *
sys.path.append("./MvImport")
from MvCameraControl_class import *
from Ui_MainWindow  import *
from CameraParams_header import *
class mywindow(QtWidgets.QMainWindow, Ui_MainWindow):
    sendAddDeviceName = pyqtSignal() #定义一个添加设备列表的信号。
    deviceList = MV_CC_DEVICE_INFO_LIST()
    g_bExit = False
    # ch:创建相机实例 | en:Creat Camera Object
    cam = MvCamera()
    def connect_and_emit_sendAddDeviceName(self):
        # Connect the sendAddDeviceName signal to a slot.
        self.sendAddDeviceName.connect(self.SelectDevice)
        # Emit the signal.
        self.sendAddDeviceName.emit()
    def __init__(self):
        super(mywindow, self).__init__()
        self.setupUi(self)
        self.connect_and_emit_sendAddDeviceName()
        self.butopenCam.clicked.connect(lambda:self.openCam(self.camSelect.currentData()))
        self.butcloseCam.clicked.connect(self.closeCam)
        # setting main window geometry
        desktop_geometry = QtWidgets.QApplication.desktop()  # 获取屏幕大小
        main_window_width = desktop_geometry.width()  # 屏幕的宽
        main_window_height = desktop_geometry.height()  # 屏幕的高
        rect = self.geometry()  # 获取窗口界面大小
        window_width = rect.width()  # 窗口界面的宽
        window_height = rect.height()  # 窗口界面的高
        x = (main_window_width - window_width) // 2  # 计算窗口左上角点横坐标
        y = (main_window_height - window_height) // 2  # 计算窗口左上角点纵坐标
        self.setGeometry(x, y, window_width, window_height)  # 设置窗口界面在屏幕上的位置
        # 无边框以及背景透明一般不会在主窗口中用到，一般使用在子窗口中，例如在子窗口中显示gif提示载入信息等等
       # self.setWindowFlags(Qt.FramelessWindowHint)
       # self.setAttribute(Qt.WA_TranslucentBackground)
    #打开摄像头。
    def openCam(self,camid):
        self.g_bExit = False
        # ch:选择设备并创建句柄 | en:Select device and create handle
        stDeviceList = cast(self.deviceList.pDeviceInfo[int(camid)], POINTER(MV_CC_DEVICE_INFO)).contents
        ret = self.cam.MV_CC_CreateHandle(stDeviceList)
        if ret != 0:
            print("create handle fail! ret[0x%x]" % ret)
            sys.exit()
        # ch:打开设备 | en:Open device
        ret = self.cam.MV_CC_OpenDevice(MV_ACCESS_Exclusive, 0)
        if ret != 0:
            print("open device fail! ret[0x%x]" % ret)
            sys.exit()
        # ch:探测网络最佳包大小(只对GigE相机有效) | en:Detection network optimal package size(It only works for the GigE camera)
        if stDeviceList.nTLayerType == MV_GIGE_DEVICE:
            nPacketSize = self.cam.MV_CC_GetOptimalPacketSize()
            if int(nPacketSize) > 0:
                ret = self.cam.MV_CC_SetIntValue("GevSCPSPacketSize", nPacketSize)
                if ret != 0:
                    print("Warning: Set Packet Size fail! ret[0x%x]" % ret)
            else:
                print("Warning: Get Packet Size fail! ret[0x%x]" % nPacketSize)
        # ch:设置触发模式为off | en:Set trigger mode as off
        ret = self.cam.MV_CC_SetEnumValue("TriggerMode", MV_TRIGGER_MODE_OFF)
        if ret != 0:
            print("set trigger mode fail! ret[0x%x]" % ret)
            sys.exit()
            # ch:获取数据包大小 | en:Get payload size
        stParam = MVCC_INTVALUE()
        memset(byref(stParam), 0, sizeof(MVCC_INTVALUE))
        ret = self.cam.MV_CC_GetIntValue("PayloadSize", stParam)
        if ret != 0:
            print("get payload size fail! ret[0x%x]" % ret)
            sys.exit()
        nPayloadSize = stParam.nCurValue
        # ch:开始取流 | en:Start grab image
        ret = self.cam.MV_CC_StartGrabbing()
        if ret != 0:
            print("start grabbing fail! ret[0x%x]" % ret)
            sys.exit()
        data_buf = (c_ubyte * nPayloadSize)()
        try:
            hThreadHandle = threading.Thread(target=self.work_thread, args=(self.cam, data_buf, nPayloadSize))
            hThreadHandle.start()
        except:
            print("error: unable to start thread")
    #关闭相机
    def closeCam(self):
        self.g_bExit=True
        # ch:停止取流 | en:Stop grab image
        ret = self.cam.MV_CC_StopGrabbing()
        if ret != 0:
            print("stop grabbing fail! ret[0x%x]" % ret)
            sys.exit()
        # ch:关闭设备 | Close device
        ret = self.cam.MV_CC_CloseDevice()
        if ret != 0:
            print("close deivce fail! ret[0x%x]" % ret)
        # ch:销毁句柄 | Destroy handle
        ret = self.cam.MV_CC_DestroyHandle()
        if ret != 0:
            print("destroy handle fail! ret[0x%x]" % ret)
    def work_thread(self,cam=0, pData=0, nDataSize=0):
        stFrameInfo = MV_FRAME_OUT_INFO_EX()
        memset(byref(stFrameInfo), 0, sizeof(stFrameInfo))
        while True:
            QIm = np.asarray(pData)  # 将c_ubyte_Array转化成ndarray得到（3686400，）
            QIm = QIm.reshape((2048, 3072, 1))  # 根据自己分辨率进行转化
                # print(temp)
                # print(temp.shape)
            QIm = cv2.cvtColor(QIm, cv2.COLOR_BGR2RGB)  # 这一步获取到的颜色不对，因为默认是BRG，要转化成RGB，颜色才正常
            pyrD1=cv2.pyrDown(QIm) #向下取样
            pyrD2 = cv2.pyrDown(pyrD1)  # 向下取样
            image_height, image_width, image_depth = pyrD2.shape  # 读取图像高宽深度
            pyrD3 = QImage(pyrD2, image_width, image_height,  image_width * image_depth,QImage.Format_RGB888)
            self.label.setPixmap(QPixmap.fromImage(pyrD3))
            #cv2.namedWindow("result", cv2.WINDOW_AUTOSIZE)
            #cv2.imshow("result", temp)
            #if cv2.waitKey(1) & 0xFF == ord('q'):
            #    break
            ret = cam.MV_CC_GetOneFrameTimeout(pData, nDataSize, stFrameInfo, 1000)
            if ret == 0:
                print("get one frame: Width[%d], Height[%d], nFrameNum[%d]" % (
                    stFrameInfo.nWidth, stFrameInfo.nHeight, stFrameInfo.nFrameNum))
            else:
                print("no data[0x%x]" % ret)
            if self.g_bExit == True:
                del pData
                break
    #获得所有相机的列表存入cmbSelectDevice中
    def SelectDevice(self):
        '''选择所有能用的相机到列表中，
             gige相机需要配合 sdk 得到。
        #得到相机列表
        tlayerType = MV_GIGE_DEVICE | MV_USB_DEVICE
    # ch:枚举设备 | en:Enum device
        ret = MvCamera.MV_CC_EnumDevices(tlayerType, self.deviceList)
        if ret != 0:
            print("enum devices fail! ret[0x%x]" % ret)
            sys.exit()
        if self.deviceList.nDeviceNum == 0:
            print("find no device!")
            sys.exit()
        print("Find %d devices!" % self.deviceList.nDeviceNum)
        for i in range(0, self.deviceList.nDeviceNum):
            mvcc_dev_info = cast(self.deviceList.pDeviceInfo[i], POINTER(MV_CC_DEVICE_INFO)).contents
            if mvcc_dev_info.nTLayerType == MV_GIGE_DEVICE:
                print("\ngige device: [%d]" % i)
                strModeName = ""
                for per in mvcc_dev_info.SpecialInfo.stGigEInfo.chModelName:
                    strModeName = strModeName + chr(per)
                print("device model name: %s" % strModeName)
                self.camSelect.addItem(strModeName,i) #写入设备列表。
    def pushbutton_function(self):
        #do some things
        Img=cv2.imread('JP1.JPG') #通过opencv读入一张图片
        image_height, image_width, image_depth=Img.shape #读取图像高宽深度
        QIm=cv2.cvtColor(Img,cv2.COLOR_BGR2RGB)
        QIm=QImage(QIm.data, image_width, image_height,  image_width * image_depth,QImage.Format_RGB888)
        self.label.setPixmap(QPixmap.fromImage(QIm))
if __name__ == '__main__':
    app = QtWidgets.QApplication(sys.argv)
    window = mywindow()
    window.show()
    sys.exit(app.exec_())

上述代码中用到的 Ui_MainWindow.py ，放到 MvImport 目录下。

代码如下：

# -*- coding: utf-8 -*-
# Form implementation generated from reading ui file 'mainWindow.ui'
# Created by: PyQt5 UI code generator 5.15.0
# WARNING: Any manual changes made to this file will be lost when pyuic5 is
# run again.  Do not edit this file unless you know what you are doing.
from PyQt5 import QtCore, QtGui, QtWidgets
class Ui_MainWindow(object):
    def setupUi(self, MainWindow):
        MainWindow.setObjectName("MainWindow")
        MainWindow.resize(589, 530)
        self.centralwidget = QtWidgets.QWidget(MainWindow)
        self.centralwidget.setObjectName("centralwidget")
        self.verticalLayout = QtWidgets.QVBoxLayout(self.centralwidget)
        self.verticalLayout.setObjectName("verticalLayout")
        self.camSelect = QtWidgets.QComboBox(self.centralwidget)
        self.camSelect.setObjectName("camSelect")
        self.verticalLayout.addWidget(self.camSelect)
        self.label = QtWidgets.QLabel(self.centralwidget)
        self.label.setObjectName("label")
        self.verticalLayout.addWidget(self.label)
        self.butopenCam = QtWidgets.QPushButton(self.centralwidget)
        self.butopenCam.setObjectName("butopenCam")
        self.verticalLayout.addWidget(self.butopenCam)
        self.butcloseCam = QtWidgets.QPushButton(self.centralwidget)
        self.butcloseCam.setObjectName("butcloseCam")
        self.verticalLayout.addWidget(self.butcloseCam)
        MainWindow.setCentralWidget(self.centralwidget)
        self.menubar = QtWidgets.QMenuBar(MainWindow)
        self.menubar.setGeometry(QtCore.QRect(0, 0, 589, 23))
        self.menubar.setObjectName("menubar")
        MainWindow.setMenuBar(self.menubar)
        self.statusbar = QtWidgets.QStatusBar(MainWindow)
        self.statusbar.setObjectName("statusbar")
        MainWindow.setStatusBar(self.statusbar)
        self.retranslateUi(MainWindow)
        QtCore.QMetaObject.connectSlotsByName(MainWindow)
    def retranslateUi(self, MainWindow):
        _translate = QtCore.QCoreApplication.translate
        MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow"))
        self.label.setText(_translate("MainWindow", "TextLabel"))
        self.butopenCam.setText(_translate("MainWindow", "打开相机"))
        self.butcloseCam.setText(_translate("MainWindow", "关闭相机"))

在python 虚拟环境中，执行 python TestVideoStream.py 运行，可以看到如下视频中的效果：

如果运行过程中提示模块不存在，可以通过 pip install 命令安装相应的模块，建议使用 清华源 ，如 安装 opencv-python ，命令如下：

pip install opencv-python==4.1.2.30 -i https://pypi.tuna.tsinghua.edu.cn/simple

通过视频中的效果可以看出：虽然实现了视频流的实时获取和显示，但是无法直接对接前端展示，不够友好。

四、最终代码（完整版）

之前的两个测试代码，仅作为测试参考，并非最终代码！！！

此段落中的代码，才是最终代码，可以重点参考！！！

使用 Python + OpenCV + Flask 实现，可以满足视频实时获取，并返回通过GET请求返回给前端进行实时显示，也可以抓取图片，保存上传。

1、添加依赖文件

将 C:\Program Files (x86)\MVS\Development\Samples\Python\ 目录下的 MvImport 目录，copy到自己的工程目录下。

2、安装插件 DirectShow

1）进入第三方插件 DirectShow 路径

cd C:\Program Files (x86)\MVS\Development\ThirdPartyPlatformAdapter\DirectShow\x64\MvDSS2

2）安装 DirectShow

使用 管理员权限 运行 InstallDSSvc_x64.bat

（本人使用的是64位Windows操作系统，运行代码也是基于64位运行，故而使用该版本；32位系统在上一目录中也存在，大家可以根据实际情况进行安装）

3、安装依赖模块

1）安装 opencv-python

pip install opencv-python==4.1.2.30 -i https://pypi.tuna.tsinghua.edu.cn/simple

个人使用的是 Python 3.8.5 ， opencv-python 对应使用 4.1.2.30 版本即可。

如果使用的 opencv-python 的版本过高，可能报如下错误：

cv2.error: Unknown C++ exception from OpenCV code.

2）安装 Flask

pip install flask -i https://pypi.tuna.tsinghua.edu.cn/simple

也可以指定 Flask 的版本，如：

pip install flask=2.2.2 -i https://pypi.tuna.tsinghua.edu.cn/simple

4、核心代码

工程代码结构如下：

0）index.html

在工程中创建 templates 目录，用于存放 index.hml

</ head > < h1 > 拍照预览 </ h1 > < img src ="{{ url_for('startPreview') }}" width ="50%" > </ body > </ html >

1）JsonResponse.py

用于规范返回给前端的数据类型，代码如下：

# -- coding: utf-8 --
class JsonResponse(object):
    统一的json返回格式
    def __init__(self, code, msg, data):
        self.code = code
        self.msg = msg
        self.data = data
    @classmethod
    def success(cls, code=0, msg='success', data=None):
        return cls(code, msg, data)
    @classmethod
    def error(cls, code=-1, msg='error', data=None):
        return cls(code, msg, data)
    def to_dict(self):
        return {
            "code": self.code,
            "msg": self.msg,
            "data": self.data
    2）JsonFlask.py
    用于重定义数据返回格式，代码如下：
# -- coding: utf-8 --
from flask import Flask, jsonify
from JsonResponse import *
class JsonFlask(Flask):
    def make_response(self, rv):
        """视图函数可以直接返回: list、dict、None"""
        if rv is None or isinstance(rv, (list, dict)):
            rv = JsonResponse.success(rv)
        if isinstance(rv, JsonResponse):
            rv = jsonify(rv.to_dict())
        return super().make_response(rv)
    3）HikRobotCamera.py
    核心代码文件，实现如下功能：
    开始预览视频流、停止预览视频流、获取图片、记录日志等功能。
    代码如下：
# -- coding: utf-8 --
import cv2
from flask import Flask, render_template, Response
import sys
import msvcrt
import base64
import datetime
import logging
sys.path.append("./MvImport")
from MvCameraControl_class import *
from JsonResponse import *
from JsonFlask import *
logging.basicConfig(level=logging.DEBUG,#控制台打印的日志级别
                    filename='hikrobot.log',
                    filemode='a',##模式，有w和a，w就是写模式，每次都会重新写日志，覆盖之前的日志
                    #a是追加模式，默认如果不写的话，就是追加模式
                    format=
                    '%(asctime)s - %(pathname)s[line:%(lineno)d] - %(levelname)s: %(message)s'
                    #日志格式
# 这里配置一下 template_folder为当前目录，不然可以找不到 index.html
app = JsonFlask(__name__, template_folder='.')
# index
@app.route('/')
def index():
    return render_template('./templates/index.html')
# 获取码流
def generate(cap):
    # 捕获异常信息
    try:
        while True:
            # 如果是关闭相机，先退出取视频流的循环
            global open
            if (not open):
                break;
            retgrab = cap.grab()
            if retgrab == True:
                logging.debug("Grab true")
            ret1, frame = cap.retrieve()
            # print(type(frame))
            if frame is None:
                logging.error("frame is None")
                continue
            ret1, jpeg = cv2.imencode('.jpg', frame)
            jpg_frame = jpeg.tobytes()
            yield (b'--frame\r\n'
                b'Content-Type: image/jpeg\r\n\r\n' + jpg_frame + b'\r\n')
    except Exception as e:
        logging.error("generate error: %s" % str(e))
# 开始预览
@app.route('/startPreview')
def startPreview():
    logging.info("======================================")
    logging.info("start to preview video stream, current_time: " + str(datetime.datetime.now()))
    # 全局变量，用于控制获取视频流的开关状态
    global open
    open = True
    # 全局变量，获取视频连接
    global cap
    cap = cv2.VideoCapture(1)
    if False == cap.isOpened():
        logging.error("can't open camera")
        quit()
    else:
        logging.info("start to open camera")
    logging.info("open camera ok")
    # 分辨率设置 3072*2048（海康机器人工业相机 MV-CU060-10GM）
    cap.set(cv2.CAP_PROP_FRAME_WIDTH, 3072)
    cap.set(cv2.CAP_PROP_FRAME_HEIGHT, 2048)
    # 帧率配置
    cap.set(cv2.CAP_PROP_FPS, 15)   
    return Response(generate(cap), mimetype='multipart/x-mixed-replace;boundary=frame')
# 停止预览
@app.route('/stopPreview')
def stopPreview():
    logging.info("======================================")
    logging.info("stop to preview video stream, current_time: " + str(datetime.datetime.now()))
    logging.info("start to close camera")
    # 全局变量，用于停止循环
    global open
    open = False
    logging.info("release resources start")
    # 全局变量，用于释放相机资源
    try:
        global cap
        cap.release()
        cv2.destroyAllWindows()
    except Exception as e:
        logging.error("stopPreview error: %s" % str(e))
    logging.info("release resources end")
    logging.info("camera closed successfully, current_time: " + str(datetime.datetime.now()))
    logging.info("======================================")
    return "stop to preview"
@app.route('/openAndSave')
def openAndSave():
    logging.info("======================================")
    logging.info("start to grab image, current_time: " + str(datetime.datetime.now()))
    code = 100000
    msg = "连接相机时发生错误"
    # img_base64 = None
    try:
        deviceList = MV_CC_DEVICE_INFO_LIST()
        tlayerType = MV_GIGE_DEVICE | MV_USB_DEVICE
        # ch:枚举设备 | en:Enum device
        ret = MvCamera.MV_CC_EnumDevices(tlayerType, deviceList)
        if ret != 0:
            logging.error("enum devices fail! ret[0x%x]" % ret)
            sys.exit()
        if deviceList.nDeviceNum == 0:
            logging.error("find no device!")
            sys.exit()
        logging.info("find %d devices!" % deviceList.nDeviceNum)
        for i in range(0, deviceList.nDeviceNum):
            mvcc_dev_info = cast(deviceList.pDeviceInfo[i], POINTER(MV_CC_DEVICE_INFO)).contents
            if mvcc_dev_info.nTLayerType == MV_GIGE_DEVICE:
                logging.info("\ngige device: [%d]" % i)
                strModeName = ""
                for per in mvcc_dev_info.SpecialInfo.stGigEInfo.chModelName:
                    strModeName = strModeName + chr(per)
                logging.info("device model name: %s" % strModeName)
                nip1 = ((mvcc_dev_info.SpecialInfo.stGigEInfo.nCurrentIp & 0xff000000) >> 24)
                nip2 = ((mvcc_dev_info.SpecialInfo.stGigEInfo.nCurrentIp & 0x00ff0000) >> 16)
                nip3 = ((mvcc_dev_info.SpecialInfo.stGigEInfo.nCurrentIp & 0x0000ff00) >> 8)
                nip4 = (mvcc_dev_info.SpecialInfo.stGigEInfo.nCurrentIp & 0x000000ff)
                logging.info("current ip: %d.%d.%d.%d\n" % (nip1, nip2, nip3, nip4))
            elif mvcc_dev_info.nTLayerType == MV_USB_DEVICE:
                logging.info("\nu3v device: [%d]" % i)
                strModeName = ""
                for per in mvcc_dev_info.SpecialInfo.stUsb3VInfo.chModelName:
                    if per == 0:
                        break
                    strModeName = strModeName + chr(per)
                logging.info("device model name: %s" % strModeName)
                strSerialNumber = ""
                for per in mvcc_dev_info.SpecialInfo.stUsb3VInfo.chSerialNumber:
                    if per == 0:
                        break
                    strSerialNumber = strSerialNumber + chr(per)
                logging.info("user serial number: %s" % strSerialNumber)
        nConnectionNum = 0
        if int(nConnectionNum) >= deviceList.nDeviceNum:
            logging.error("intput error!")
            sys.exit()
        # ch:创建相机实例 | en:Creat Camera Object
        cam = MvCamera()
        # ch:选择设备并创建句柄 | en:Select device and create handle
        stDeviceList = cast(deviceList.pDeviceInfo[int(nConnectionNum)], POINTER(MV_CC_DEVICE_INFO)).contents
        ret = cam.MV_CC_CreateHandle(stDeviceList)
        if ret != 0:
            logging.error("create handle fail! ret[0x%x]" % ret)
            sys.exit()
        # ch:打开设备 | en:Open device
        ret = cam.MV_CC_OpenDevice(MV_ACCESS_Exclusive, 0)
        if ret != 0:
            logging.error("open device fail! ret[0x%x]" % ret)
            sys.exit()
        # ch:探测网络最佳包大小(只对GigE相机有效) | en:Detection network optimal package size(It only works for the GigE camera)
        if stDeviceList.nTLayerType == MV_GIGE_DEVICE:
            nPacketSize = cam.MV_CC_GetOptimalPacketSize()
            if int(nPacketSize) > 0:
                ret = cam.MV_CC_SetIntValue("GevSCPSPacketSize", nPacketSize)
                if ret != 0:
                    logging.warn("Warning: Set Packet Size fail! ret[0x%x]" % ret)
            else:
                logging.warn("Warning: Get Packet Size fail! ret[0x%x]" % nPacketSize)
        # ch:设置触发模式为off | en:Set trigger mode as off
        ret = cam.MV_CC_SetEnumValue("TriggerMode", MV_TRIGGER_MODE_OFF)
        if ret != 0:
            logging.error("set trigger mode fail! ret[0x%x]" % ret)
            sys.exit()
        # ch:获取数据包大小 | en:Get payload size
        stParam = MVCC_INTVALUE()
        memset(byref(stParam), 0, sizeof(MVCC_INTVALUE))
        ret = cam.MV_CC_GetIntValue("PayloadSize", stParam)
        if ret != 0:
            logging.error("get payload size fail! ret[0x%x]" % ret)
            sys.exit()
        nPayloadSize = stParam.nCurValue
        # ch:开始取流 | en:Start grab image
        ret = cam.MV_CC_StartGrabbing()
        if ret != 0:
            logging.error("start grabbing fail! ret[0x%x]" % ret)
            sys.exit()
        stDeviceList = MV_FRAME_OUT_INFO_EX()
        memset(byref(stDeviceList), 0, sizeof(stDeviceList))
        data_buf = (c_ubyte * nPayloadSize)()
        ret = cam.MV_CC_GetOneFrameTimeout(byref(data_buf), nPayloadSize, stDeviceList, 1000)
        if ret == 0:
            logging.info("get one frame: Width[%d], Height[%d], nFrameNum[%d]" % (stDeviceList.nWidth, stDeviceList.nHeight, stDeviceList.nFrameNum))
            nRGBSize = stDeviceList.nWidth * stDeviceList.nHeight * 3
            stConvertParam=MV_SAVE_IMAGE_PARAM_EX()
            stConvertParam.nWidth = stDeviceList.nWidth
            stConvertParam.nHeight = stDeviceList.nHeight
            stConvertParam.pData = data_buf
            stConvertParam.nDataLen = stDeviceList.nFrameLen
            stConvertParam.enPixelType = stDeviceList.enPixelType
            stConvertParam.nImageLen = stConvertParam.nDataLen
            stConvertParam.nJpgQuality = 70
            stConvertParam.enImageType = MV_Image_Jpeg
            stConvertParam.pImageBuffer = (c_ubyte * nRGBSize)()
            stConvertParam.nBufferSize = nRGBSize
            # ret = cam.MV_CC_ConvertPixelType(stConvertParam)
            logging.info("nImageLen: %d" % stConvertParam.nImageLen)
            ret = cam.MV_CC_SaveImageEx2(stConvertParam)
            if ret != 0:
                logging.error("convert pixel fail ! ret[0x%x]" % ret)
                del data_buf
                sys.exit()
            #file_path = "AfterConvert_RGB2.jpg"
            #file_open = open(file_path, 'wb+')
            #file_open = open(file_path.encode('utf8'), 'wb')
            img_buff = (c_ubyte * stConvertParam.nImageLen)()
            cdll.msvcrt.memcpy(byref(img_buff), stConvertParam.pImageBuffer, stConvertParam.nImageLen)
            #file_open.write(img_buff)
            # 对返回的图片进行 base64 格式转换
            img_base64 = "data:image/jpg;base64," + str(base64.b64encode(img_buff)).split("'")[1]
            code = 200
            msg = "success"
        logging.info("Save Image succeed!")
        # ch:停止取流 | en:Stop grab image
        ret = cam.MV_CC_StopGrabbing()
        if ret != 0:
            logging.error("stop grabbing fail! ret[0x%x]" % ret)
            del data_buf
            sys.exit()
        # ch:关闭设备 | Close device
        ret = cam.MV_CC_CloseDevice()
        if ret != 0:
            logging.error("close deivce fail! ret[0x%x]" % ret)
            del data_buf
            sys.exit()
        # ch:销毁句柄 | Destroy handle
        ret = cam.MV_CC_DestroyHandle()
        if ret != 0:
            logging.error("destroy handle fail! ret[0x%x]" % ret)
            del data_buf
            sys.exit()
        del data_buf
    except Exception as e:
        logging.error("openAndSave error: %s" % str(e))
    # print("openAndSave finished, current_time: " + str(datetime.datetime.now()))  
    return JsonResponse(code, msg, img_base64)
# 执行web服务, 端口号可自行修订
logging.info("start to run camera app, current_time: " + str(datetime.datetime.now()))
app.run(host='0.0.0.0', port=65432, debug=True, threaded=True)
    5、运行代码
    进入Python虚拟环境，执行如下命令：




    

python HikRobotCamera.py
    6、功能验证
    1）开始预览
    可以将 http://127.0.0.1:65432/startPreview 在前端用 img 标签 显示视频的实时预览效果。
http://127.0.0.1:65432/startPreview
    2）停止预览
    由于使用的这款海康机器人工业相机（MV-CU060-10GM）只能创建一个连接，所以，当预览完实时视频，需要调用该接口释放相机资源，避免资源被长期占用。
http://127.0.0.1:65432/stopPreview
    3）获取图片
    返回 base64 格式 的图片，前端可以直接接收显示，调用上传接口保存。
http://127.0.0.1:65432/openAndSave
    7、运行效果
    由于网速问题和相机没有光圈，相机的拍摄效果有点不清晰。运行效果如下：
    8、日志查看
    工程目录下回生产日志文件 hikrobot.log，内容如下：
HikRobotCamera.py 的改良优化版，对获取图片方法做了简化，更为简洁，代码如下：
# -- coding: utf-8 --
import cv2
from flask import Flask, render_template, Response
import sys
import msvcrt
import base64
import datetime
import logging
sys.path.append("./MvImport")
from MvCameraControl_class import *
from JsonResponse import *
from JsonFlask import *
logging.basicConfig(level=logging.DEBUG,#控制台打印的日志级别
                    filename='hikrobot.log',
                    filemode='a',##模式，有w和a，w就是写模式，每次都会重新写日志，覆盖之前的日志
                    #a是追加模式，默认如果不写的话，就是追加模式
                    format=
                    '%(asctime)s - %(pathname)s[line:%(lineno)d] - %(levelname)s: %(message)s'
                    #日志格式
# 这里配置一下 template_folder为当前目录，不然可以找不到 index.html
app = JsonFlask(__name__, template_folder='.')
# index
@app.route('/')
def index():
    return render_template('./templates/index.html')
# 获取码流
def generate(cap):
    # 捕获异常信息
    try:
        while True:
            # 如果是关闭相机，先退出取视频流的循环
            global open
            if (not open):
                break;
            retgrab = cap.grab()
            if retgrab == True:
                logging.debug("Grab true")
            ret1, frame = cap.retrieve()
            # print(type(frame))
            if frame is None:
                logging.error("frame is None")
                continue
            ret1, jpeg = cv2.imencode('.jpg', frame)
            jpg_frame = jpeg.tobytes()
            yield (b'--frame\r\n'
                b'Content-Type: image/jpeg\r\n\r\n' + jpg_frame + b'\r\n')
    except Exception as e:
        logging.error("generate error: %s" % str(e))
# 开始预览
@app.route('/startPreview')
def startPreview():
    logging.info("================== startPreview start ====================")
    logging.info("start to preview video stream, current_time: " + str(datetime.datetime.now()))
    # 全局变量，用于控制获取视频流的开关状态
    try:
        global open
        open = True
        # 全局变量，获取视频连接
        global cap
        cap = cv2.VideoCapture(1)
        if False == cap.isOpened():
            logging.error("startPreview -- can't open camera")
            quit()
        else:
            logging.info("startPreview -- start to open camera")
        logging.info("startPreview -- open camera ok")
        # 分辨率设置 3072*2048（海康机器人工业相机 MV-CU060-10GM）
        cap.set(cv2.CAP_PROP_FRAME_WIDTH, 3072)
        cap.set(cv2.CAP_PROP_FRAME_HEIGHT, 2048)
        # 帧率配置
        cap.set(cv2.CAP_PROP_FPS, 15)   
        response = Response(generate(cap), mimetype='multipart/x-mixed-replace;boundary=frame')
    except Exception as e:
        logging.error("startPreview error: %s" % str(e))
    return response
# 停止预览
@app.route('/stopPreview')
def stopPreview():
    logging.info("================== stopPreview start ====================")
    logging.info("stop to preview video stream, current_time: " + str(datetime.datetime.now()))
    logging.info("start to close camera")
    # 全局变量，用于停止循环
    global open
    open = False
    logging.info("release resources start")
    # 全局变量，用于释放相机资源
    try:
        global cap
        cap.release()
        cv2.destroyAllWindows()
    except Exception as e:
        logging.error("stopPreview error: %s" % str(e))
    logging.info("release resources end")
    logging.info("camera closed successfully, current_time: " + str(datetime.datetime.now()))
    logging.info("=================== stopPreview end ===================")
    return "stop to preview"
# 获取base64图片
@app.route('/grabImage')
def grabImage():
    code = 100000
    msg = "连接相机时发生错误"
    # 捕获异常信息
    try:
        print("grabImage -- stopPreview start")
        stopPreview()
        print("grabImage -- stopPreview end")
        # 全局变量，获取视频连接
        global cap
        cap = cv2.VideoCapture(1)
        if False == cap.isOpened():
            logging.error("can't open camera")
            quit()
        else:
            logging.info("grabImage -- start to open camera")
        logging.info("grabImage -- open camera ok")
        # 分辨率设置 3072*2048（海康机器人工业相机 MV-CU060-10GM）
        cap.set(cv2.CAP_PROP_FRAME_WIDTH, 3072)
        cap.set(cv2.CAP_PROP_FRAME_HEIGHT, 2048)
        # 帧率配置
        cap.set(cv2.CAP_PROP_FPS, 15)   
        retgrab1 = cap.grab()
        if retgrab1 == True:
            logging.debug("grabImage -- Grab true")
        ret1, frame = cap.retrieve()
        ret1, jpeg = cv2.imencode('.jpg', frame)
        img_buff = jpeg.tobytes()
        # 对返回的图片进行 base64 格式转换
        img_base64 = "data:image/jpg;base64," + str(base64.b64encode(img_buff)).split("'")[1]
        code = 200
        msg = "success"
        stopPreview()
    except Exception as e:
        logging.error("generate error: %s" % str(e))
    return JsonResponse(code, msg, img_base64)
# 获取base64图片
@app.route('/hik/openAndSave')
def openAndSave():
    code = 100000
    msg = "连接相机时发生错误"
    # 捕获异常信息
    try:
        logging.info("================= openAndSave start =====================")
        # 拍照之前，先停止预览
        stopPreview()
        logging.info("start to grab image, current_time: " + str(datetime.datetime.now()))
        # 全局变量，获取视频连接
        global cap
        cap = cv2.VideoCapture(1)
        if False == cap.isOpened():
            logging.error("openAndSave -- can't open camera")
            quit()
        else:
            logging.info("openAndSave -- start to open camera")
        logging.info("openAndSave -- open camera ok")
        # 分辨率设置 3072*2048（海康机器人工业相机 MV-CU060-10GM）
        cap.set(cv2.CAP_PROP_FRAME_WIDTH, 3072)
        cap.set(cv2.CAP_PROP_FRAME_HEIGHT, 2048)
        # 帧率配置
        cap.set(cv2.CAP_PROP_FPS, 15)   
        retgrab1 = cap.grab()
        if retgrab1 == True:
            logging.debug("openAndSave -- Grab true")
        ret1, frame = cap.retrieve()
        ret1, jpeg = cv2.imencode('.jpg', frame)
        img_buff = jpeg.tobytes()
        # 对返回的图片进行 base64 格式转换
        img_base64 = "data:image/jpg;base64," + str(base64.b64encode(img_buff)).split("'")[1]
        code = 200
        msg = "success"
        stopPreview()
        logging.info("================= openAndSave end =====================")
    except Exception as e:
        logging.error("openAndSave error: %s" % str(e))
    return JsonResponse(code, msg, img_base64)
@app.route('/hik/openAndSave2')
def openAndSave2():
    # 拍照之前，先停止预览
    stopPreview()
    logging.info("======================================")
    logging.info("start to grab image, current_time: " + str(datetime.datetime.now()))
    code = 100000
    msg = "连接相机时发生错误"
    # img_base64 = None
    try:
        deviceList = MV_CC_DEVICE_INFO_LIST()
        tlayerType = MV_GIGE_DEVICE | MV_USB_DEVICE
        # ch:枚举设备 | en:Enum device
        ret = MvCamera.MV_CC_EnumDevices(tlayerType, deviceList)
        if ret != 0:
            logging.error("enum devices fail! ret[0x%x]" % ret)
            sys.exit()
        if deviceList.nDeviceNum == 0:
            logging.error("find no device!")
            sys.exit()
        logging.info("find %d devices!" % deviceList.nDeviceNum)
        for i in range(0, deviceList.nDeviceNum):
            mvcc_dev_info = cast(deviceList.pDeviceInfo[i], POINTER(MV_CC_DEVICE_INFO)).contents
            if mvcc_dev_info.nTLayerType == MV_GIGE_DEVICE:
                logging.info("\ngige device: [%d]" % i)
                strModeName = ""
                for per in mvcc_dev_info.SpecialInfo.stGigEInfo.chModelName:
                    strModeName = strModeName + chr(per)
                logging.info("device model name: %s" % strModeName)
                nip1 = ((mvcc_dev_info.SpecialInfo.stGigEInfo.nCurrentIp & 0xff000000) >> 24)
                nip2 = ((mvcc_dev_info.SpecialInfo.stGigEInfo.nCurrentIp & 0x00ff0000) >> 16)
                nip3 = ((mvcc_dev_info.SpecialInfo.stGigEInfo.nCurrentIp & 0x0000ff00) >> 8)
                nip4 = (mvcc_dev_info.SpecialInfo.stGigEInfo.nCurrentIp & 0x000000ff)
                logging.info("current ip: %d.%d.%d.%d\n" % (nip1, nip2, nip3, nip4))
            elif mvcc_dev_info.nTLayerType == MV_USB_DEVICE:
                logging.info("\nu3v device: [%d]" % i)
                strModeName = ""
                for per in mvcc_dev_info.SpecialInfo.stUsb3VInfo.chModelName:
                    if per == 0:
                        break
                    strModeName = strModeName + chr(per)
                logging.info("device model name: %s" % strModeName)
                strSerialNumber = ""
                for per in mvcc_dev_info.SpecialInfo.stUsb3VInfo.chSerialNumber:
                    if per == 0:
                        break
                    strSerialNumber = strSerialNumber + chr(per)
                logging.info("user serial number: %s" % strSerialNumber)
        nConnectionNum = 0
        if int(nConnectionNum) >= deviceList.nDeviceNum:
            logging.error("intput error!")
            sys.exit()
        # ch:创建相机实例 | en:Creat Camera Object
        cam = MvCamera()
        # ch:选择设备并创建句柄 | en:Select device and create handle
        stDeviceList = cast(deviceList.pDeviceInfo[int(nConnectionNum)], POINTER(MV_CC_DEVICE_INFO)).contents
        ret = cam.MV_CC_CreateHandle(stDeviceList)
        if ret != 0:
            logging.error("create handle fail! ret[0x%x]" % ret)
            sys.exit()
        # ch:打开设备 | en:Open device
        ret = cam.MV_CC_OpenDevice(MV_ACCESS_Exclusive, 0)
        if ret != 0:
            logging.error("open device fail! ret[0x%x]" % ret)
            sys.exit()
        # ch:探测网络最佳包大小(只对GigE相机有效) | en:Detection network optimal package size(It only works for the GigE camera)
        if stDeviceList.nTLayerType == MV_GIGE_DEVICE:
            nPacketSize = cam.MV_CC_GetOptimalPacketSize()
            if int(nPacketSize) > 0:
                ret = cam.MV_CC_SetIntValue("GevSCPSPacketSize", nPacketSize)
                if ret != 0:
                    logging.warn("Warning: Set Packet Size fail! ret[0x%x]" % ret)
            else:
                logging.warn("Warning: Get Packet Size fail! ret[0x%x]" % nPacketSize)
        # ch:设置触发模式为off | en:Set trigger mode as off
        ret = cam.MV_CC_SetEnumValue("TriggerMode", MV_TRIGGER_MODE_OFF)
        if ret != 0:
            logging.error("set trigger mode fail! ret[0x%x]" % ret)
            sys.exit()
        # ch:获取数据包大小 | en:Get payload size
        stParam = MVCC_INTVALUE()
        memset(byref(stParam), 0, sizeof(MVCC_INTVALUE))
        ret = cam.MV_CC_GetIntValue("PayloadSize", stParam)
        if ret != 0:
            logging.error("get payload size fail! ret[0x%x]" % ret)
            sys.exit()
        nPayloadSize = stParam.nCurValue
        # ch:开始取流 | en:Start grab image
        ret = cam.MV_CC_StartGrabbing()
        if ret != 0:
            logging.error("start grabbing fail! ret[0x%x]" % ret)
            sys.exit()
        stDeviceList = MV_FRAME_OUT_INFO_EX()
        memset(byref(stDeviceList), 0, sizeof(stDeviceList))
        data_buf = (c_ubyte * nPayloadSize)()
        ret = cam.MV_CC_GetOneFrameTimeout(byref(data_buf), nPayloadSize, stDeviceList, 1000)
        if ret == 0:
            logging.info("get one frame: Width[%d], Height[%d], nFrameNum[%d]" % (stDeviceList.nWidth, stDeviceList.nHeight, stDeviceList.nFrameNum))
            nRGBSize = stDeviceList.nWidth * stDeviceList.nHeight * 3
            stConvertParam=MV_SAVE_IMAGE_PARAM_EX()
            stConvertParam.nWidth = stDeviceList.nWidth
            stConvertParam.nHeight = stDeviceList.nHeight
            stConvertParam.pData = data_buf
            stConvertParam.nDataLen = stDeviceList.nFrameLen
            stConvertParam.enPixelType = stDeviceList.enPixelType
            stConvertParam.nImageLen = stConvertParam.nDataLen
            stConvertParam.nJpgQuality = 70
            stConvertParam.enImageType = MV_Image_Jpeg
            stConvertParam.pImageBuffer = (c_ubyte * nRGBSize)()
            stConvertParam.nBufferSize = nRGBSize
            # ret = cam.MV_CC_ConvertPixelType(stConvertParam)
            logging.info("nImageLen: %d" % stConvertParam.nImageLen)
            ret = cam.MV_CC_SaveImageEx2(stConvertParam)
            if ret != 0:
                logging.error("convert pixel fail ! ret[0x%x]" % ret)
                del data_buf
                sys.exit()
            #file_path = "AfterConvert_RGB2.jpg"
            #file_open = open(file_path, 'wb+')
            #file_open = open(file_path.encode('utf8'), 'wb')
            img_buff = (c_ubyte * stConvertParam.nImageLen)()
            cdll.msvcrt.memcpy(byref(img_buff), stConvertParam.pImageBuffer, stConvertParam.nImageLen)
            #file_open.write(img_buff)
            # 对返回的图片进行 base64 格式转换
            img_base64 = "data:image/jpg;base64," + str(base64.b64encode(img_buff)).split("'")[1]
            code = 200
            msg = "success"
        logging.info("Save Image succeed!")
        # ch:停止取流 | en:Stop grab image
        ret = cam.MV_CC_StopGrabbing()
        if ret != 0:
            logging.error("stop grabbing fail! ret[0x%x]" % ret)
            del data_buf
            sys.exit()
        # ch:关闭设备 | Close device
        ret = cam.MV_CC_CloseDevice()
        if ret != 0:
            logging.error("close deivce fail! ret[0x%x]" % ret)
            del data_buf
            sys.exit()
        # ch:销毁句柄 | Destroy handle
        ret = cam.MV_CC_DestroyHandle()
        if ret != 0:
            logging.error("destroy handle fail! ret[0x%x]" % ret)
            del data_buf
            sys.exit()
        del data_buf
    except Exception as e:
        logging.error("openAndSave error: %s" % str(e))
    # print("openAndSave finished, current_time: " + str(datetime.datetime.now()))  
    return JsonResponse(code, msg, img_base64)
# 执行web服务, 端口号可自行修订
logging.info("start to run camera app, current_time: " + str(datetime.datetime.now()))
if __name__ == '__main__':
    try:
        app.run(host='0.0.0.0', port=65432, debug=True, threaded=True)
    except Exception as e:
        logging.error("app error: %s" % str(e))