头文件更改

默认的头文件引用是

#include <opencv2/core/core.hpp>
#include <opencv2/imgproc/imgproc.hpp>
#include <opencv2/highgui/highgui.hpp>

但是在ubuntu20中/usr/include中默认的是opencv4，他文件夹里面才是opencv2，需要我们手动拷贝出来才行。

cd /usr/include
sudo ln -s opencv4/opencv2 opencv2

cmakelist更改

需要加上opencv的库

set(OpenCV_DIR "${CMAKE_CURRENT_SOURCE_DIR}/usr/lib/x86_64-linux-gnu/cmake/opencv4")
find_package(OpenCV REQUIRED)
include_directories(${OpenCV_INCLUDE_DIRS})target_link_libraries(test ${OpenCV_LIBS})

代码修改

CV_RGB2GRAY

将

cvtColor(src, grayImg, CV_RGB2GRAY);

修改为

cvtColor(src, grayImg, COLOR_RGB2GRAY);

并添加头文件

#include <opencv2/imgproc/types_c.h>

参考文章

如何解决 opencv2/core.hpp: No such file or directory“ for opencv4
ubuntu20.04下opencv版本不兼容问题