OpenCV error: ‘CV_BGR2GRAY’ was not declared in this scope错误

本人在学习OpenCV时按照书上的代码敲：

cvtColor(srcImage,grayImage,COLOR_BGR2GRAY );

这里遇到报错：

error: ‘CV_BGR2GRAY’ was not declared in this scope
     cvtColor(srcImage,grayImage,CV_BGR2GRAY );

一直不解，查了半天才发现是由于版本更新，CV_BGR2GRAY改为了COLOR_BGR2GRAY。

且所有都发生了变化需将CV改为COLOR。