error: ‘CV_BGR2GRAY’ was not declared in this scope

原博客搬移到：https://blog.csdn.net/u013171226/article/details/108062603

 

 

某项目中opencv版本由opencv3更换为opencv4之后，之前的代码编译出错，

error: ‘CV_BGR2GRAY’ was not declared in this scope

这是由于版本更新，宏定义发生了改变。

修改方法为：将CV_BGR2GRAY改为cv::COLOR_BGR2GRAY