如何在代码中区分OpenCV版本 如何区分是OpenCV2还是OpenCV3

1、C++

OpenCV在C++中的版本号在里面，贴出部分和版本相关的定义

// opencv2
#define CV_VERSION_EPOCH    2
#define CV_VERSION_MAJOR    4
#define CV_VERSION_MINOR    13
#define CV_VERSION_REVISION 4

//opencv3
#define CV_VERSION_MAJOR    3
#define CV_VERSION_MINOR    4
#define CV_VERSION_REVISION 1
#define CV_VERSION_STATUS   ""

CV_VERSION_EPOCH是OpenCV2指定主版本号“2”的宏定义，只在OpenCV2中有，因此可使用如下代码来区分是OpenCV2还是OpenCV3

#include 
#include 
#include 

using namespace cv;

#if CV_VERSION_EPOCH == 2
#define OPENCV2
#elif CV_VERSION_MAJOR == 3
#define  OPENCV3
#else
#error Not support this OpenCV version
#endif

int main() {
#ifdef OPENCV2
    std::cout << "Hello, OpenCV2!" << std::endl;
#elif defined(OPENCV3)
    std::cout << "Hello, OpenCV3!" << std::endl;
#endif
    return 0;
}

2、Python

import cv2

if __name__ == "__main__":
    version = cv2.__version__
    if version.split('.')[0]=="3":
        print("this is opencv3")
    else:
        print("this is opencv2")