记录 vs2019+opencv4.7.0+cuda11.8 cmake编译

原文链接：cmake 编译opencv4.5.5/opencv4.6.0/opencv4.7.0 gpu版以及vs2022配置opencv-gpu_小广向前进的博客-CSDN博客

1、Debug

 这里可以改编译Debug还是Release，默认是Release。

2、测试代码

#include <iostream>
#include "opencv2/core.hpp"
#include "opencv2/cudaarithm.hpp"
#include <opencv2/opencv.hpp>
#include <opencv2/highgui.hpp>
#include <opencv2/cudafeatures2d.hpp>
#include <opencv2/xfeatures2d/cuda.hpp>

using namespace std;
using namespace cv;
using namespace cv::cuda;
int main()
{
    int num_devices = getCudaEnabledDeviceCount();
    if (num_devices == 0)
    {
        std::cout << "OpenCV is compiled without CUDA support" << endl;
        return -1;
    }
    else if (num_devices == -1)
    {
        std::cout << "CUDA driver is not installed" << endl;
        return -1;
    }
    else if (num_devices >= 1)
    {
        std::cout << "CUDA-Opencv can be used and the number of GPU is :" << num_devices << endl;
        return -1;
    }
    return 0;
}

当num_devices等于0的时候，表示没有使用gpu，可能的原因有两个：一是cuda没配置好，二是受到以前配置过cpu版的opencv的影响，在vs配置里面把之前的opencv路径都去掉，然后在环境变量那里，将cpu版的opencv路径移动到gpu版的路径下方。