opencv timer

以下是使用OpenCV计时器的示例代码：

#include "opencv2/opencv.hpp"
using namespace cv;

int main()
{
    TickMeter tm;
    tm.start();

    // 待测试的代码
    // ...

    tm.stop();
    printf("Time elapsed: %fms\n", tm.getTimeMilli());
    return 0;
}

另外，你也可以使用C++11的chrono库来计时：

#include <iostream>
#include <chrono>
#include <thread>

int main()
{
    auto start = std::chrono::high_resolution_clock::now();

    // 待测试的代码
    // ...
    std::this_thread::sleep_for(std::chrono::milliseconds(1000));

    auto end = std::chrono::high_resolution_clock::now();
    std::chrono::duration<double, std::milli> elapsed = end - start;
    std::cout << "Time elapsed: " << elapsed.count() << "ms\n";
    return 0;
}