一.下载OpenCV4.0的安装文件：

OpenCV官网

然后安装到你想要的地方

二.添加到Path里面：

并且把文件opencv_world400.dll和opencv_world400d.dll文件复制到
  C:\Windows\SysWOW64这个文件夹；

三.配置Vs2019环境（OpenCV4.0只能用x64配置）

1.在把opencv的include添加到Include Directories和vc15\lib添加到Library Directories

2.在把opencv_world400d.lib添加到Additional Dependencies

运行代码

 

#include <iostream>
#include <opencv2/highgui.hpp>
#include <opencv2/core.hpp>
#include <opencv2/imgcodecs.hpp>


using namespace cv;
using namespace std;

int main()
{
	Mat image;
	image = imread("C:/Users/Kiripeng/Desktop/out-2950.jpg"); 

	if (image.empty()) 
	{
		cout << "Could not open or find the image" << std::endl;
		return -1;
	}


	namedWindow("Display window", WINDOW_AUTOSIZE); 
	imshow("Display window", image); 

	waitKey(0);

	std::cout << "Hello World!\n";
}