CMakeLists.txt与OpenCV
在Linux下安装了两个版本的Opencv，一个2.4.9在默认路径下：
/usr/local/share/OpenCV/OpenCVConfig.cmake
一个3.4.9安装在自定义路径下：
/usr/local/include/opencv3.4.9/share/OpenCV/OpenCVConfig.cmake
在调用自定义的opencv版本时CMakeLists.txt内容如下：
1 # cmake needs this line 2 cmake_minimum_required (VERSION 2.8) 3 # Define project name 4 project(TestOpencv) 5 6 # Find OpenCV, you may need to set OpenCV_DIR variable 7 # to the absolute path to the directory containing OpenCVConfig.cmake file 8 # via the command line or GUI 9 set(OpenCV_DIR /usr/local/include/opencv3.4.9/share/OpenCV) 10 find_package(OpenCV 3 REQUIRED) 11 message(STATUS "Opencv library status: ") 12 message(STATUS "> version: ${OpenCV_VERSION} ") 13 message(STATUS "> libraries: ${OpenCV_LIBS}") 14 message(STATUS "> include: ${OpenCV_INCLUDE_DIRS} ") 15 16 # Add OpenCV headers location to your include paths 17 include_directories(${OpenCV_INCLUDE_DIRS}) 18 19 20 # Declare the executable target built from your sources 21 add_executable(main main.cpp) 22 23 # Link your application with OpenCV libraries 24 target_link_libraries(main ${OpenCV_LIBS})
其中line 9 很重要，如果没有set 路径的话会找到默认路径下的opencv 2.4.9，从而不匹配 find_package(OpenCV 3 REQUIRED) 而报错。
如果只是用opencv2.4.9就不需要line 9,然后 find_package(OpenCV 3 REQUIRED) 改成 find_package(OpenCV 2 REQUIRED) 或 find_package(OpenCV REQUIRED)
文件路径结构：
|--build | |--CMakeLists.txt | |--main.cpp
|
|--test
|
|--1.jpg
其中build是新建的文件夹。
main.cpp内容如下：
1 #include <stdio.h> 2 #include "opencv2/opencv.hpp" 3 4 int main() 5 { 6 cv::Mat image = cv::imread("../test/1.jpg"); 7 printf("image.col=%d image.raw=%d \n", image.cols, image.raws); 8 9 cv::imshow("picture",image); 10 cv::waitKey(0); 11 return 0; 12 13 }
在build目录下执行：
cmake ..
生成nakefile文件，接着执行编译命令：
make
这样会生成一个可执行程序 main
执行程序：
./main
