耗时统计

简单统计

#include<Windows.h>

DWORD startTime = GetTickCount();//计时开始
...代码块
DWORD endTime = GetTickCount();//计时结束
cout << "耗时：" << endTime - startTime << "ms" << endl;

或

#include<Windows.h>

LARGE_INTEGER freq, start, end;

int main() {
    QueryPerformanceFrequency(&freq);
    QueryPerformanceCounter(&start);
    //...代码块
    QueryPerformanceCounter(&end);
    double cost = (end.QuadPart - start.QuadPart);
    cost = (cost * 1000 / freq.QuadPart); //ms

    return 0;
}

精确统计

#include<chrono>

auto start=std::chrono::high_resolution_clock::now();
...代码块
auto end = std::chrono::high_resolution_clock::now();
cout << "耗时：" << std::chrono::duration_cast<std::chrono::milliseconds>(end - start).count() << "ms" << endl;

 OpenCV方式：

double t = (double)getTickCount();
// 需要被测量的程序段
t = ((double)getTickCount() - t)/getTickFrequency();
cout << "执行时间(秒): " << t << endl;