切换OPENCV版本

…
set(OpenCV_DIR /usr/lib/cmake/opencv4) # 设置opencv4的OpenCVConfig.cmake文件
find_package(OpenCV REQUIRED)
include_directories(${OpenCV_INCLUDE_DIRS})
message(STATUS "Opencv_include_Path: " ${OpenCV_INCLUDE_DIRS})
message(STATUS "Opencv_Library_Path: " ${Opencv_LIBRARIES})