加头文件:
#include <opencv2/opencv.hpp>
#include "stdafx.h"
#include <opencv2/opencv.hpp>
#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <opencv2/imgproc/imgproc.hpp>
#include <opencv2/video/background_segm.hpp>
#include <iostream>
#include <math.h>
【转载自】
未定义的标识符blur ，Canny，cedge，cvtColor_qq_35366466的博客-CSDN博客 https://blog.csdn.net/qq_35366466/article/details/83387069