python 调用海康SDK 抓图

你可以使用海康SDK提供的HCNetSDK.dll库文件来调用它的抓图功能。以下是一个简单的示例代码，可以帮助你开始：

import sys
import os
from ctypes import *

# 加载HCNetSDK.dll
dll_path = os.path.join(os.getcwd(), "HCNetSDK.dll")
hcnetsdk = windll.LoadLibrary(dll_path)

# 登录设备
def login_device(ip, port, username, password):
    device_info = hcnetsdk.NET_DVR_DEVICEINFO_V30()
    lUserID = hcnetsdk.NET_DVR_Login_V30(ip.encode('utf-8'), port, username.encode('utf-8'), password.encode('utf-8'), byref(device_info))
    if lUserID < 0:
        print("登录失败，错误码：", hcnetsdk.NET_DVR_GetLastError())
        return -1
    else:
        print("登录成功，用户ID：", lUserID)
        return lUserID

# 抓图
def capture_picture(lUserID):
    pic_path = "snapshot.jpg"
    pic_size = 1024 * 1024
    pic_buffer = create_string_buffer(pic_size)
    ret = hcnetsdk.NET_DVR_CaptureJPEGPicture(lUserID, 1, byref(pic_buffer), pic_size, byref(c_long(0)))
    if ret > 0:
        with open(pic_path, "wb") as f:
            f.write(pic_buffer.raw[:ret])
            print("抓图成功，图片已保存到：", pic_path)
    else:
        print("抓图失败，错误码：", hcnetsdk.NET_DVR_GetLastError())

# 退出登录
def logout_device(lUserID):
    hcnetsdk.NET_DVR_Logout(lUserID)

if __name__ == '__main__':
    ip = "192.168.1.64"  # 设备IP地址
    port = 8000  # 设备端口号
    username = "admin"  # 登录用户名
    password = "12345"  # 登录密码

    lUserID = login_device(ip, port, username, password)
    if lUserID < 0:
        sys.exit()

    capture_picture(lUserID)

    logout_device(lUserID)

需要注意的是，此示例仅适用于海康SDK V5.3以上版本。在使用该示例前，你需要安装海康SDK并且根据你的Python版本安装相应的ctypes模块。