下载opencv
下载链接：
https://opencv.org/releases/
如： opencv-4.3.0-vc14_vc15.exe
运行exe
运行exe（其实是解压），将压缩包解压到相应目录，如：
D:
解压后会生成opencv文件夹。
其中build是OpenCV使用时要用到的一些库文件，而sources中则是OpenCV官方为我们提供的一些demo示例源码
Win+VS
添加环境变量
根据安装目录新建环境变量：
此电脑 - 属性 - 高级系统设置 - 高级 - 环境变量 - 系统变量(s) - path - 双击 - 新建 - D:opencvuildx64vc15in
测试opencv
新建vs2019工程
如 ：Test。
添加静态库和动态库
解决方案管理器 - Test - 右键 - 属性 - 配置属性 - VC++目录 - 平台（x64）
- 包含目录(Include Directories) -
D:opencvuildinclude和D:opencvuildincludeopencv2 - 库目录(Library Directories) -
D:opencvuildx64vc15lib
添加动态连接器
打开D:opencvuildx64vc15lib，会看到里边有连接器opencv_world430d.lib，然后，
解决方案管理器 - Test - 右键 - 属性 - 配置属性 - 链接器 - 输入 - 平台（x64） - 附加依赖项 - opencv_world430d.lib
这一步和include是等价的。
确定。
样例
vs2019 Debug x64 环境
#include<iostream>
#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>
using namespace cv;
int main()
{
// 读入一张图片（游戏原画）
Mat img = imread("C://Users//Administrator//Desktop//test.jpg");
if (img.empty())
{
std::cout << "No image! Maybe the image path is wrong!" << std::endl;
int i;
std::cin >> i;
return 0;
}
// 创建一个名为 "游戏原画"窗口
namedWindow("游戏原画");
// 在窗口中显示游戏原画
imshow("游戏原画", img);
// 等待6000 ms后窗口自动关闭
waitKey(0);
}
弹出图片就对了！
Win+MinGW
如果QT用的编译器是MinGW，那么则无法编译.lib后缀的库文件，所以需要准备.a后缀的opencv库文件。opencv244版本带有mingw的库文件，但opencv2410以后则没有了。
安装QT
QT需要的两个模块：
Qt-Qt5.9-MingGW 5.3.0 32 bit
Qt-Tools-MinGW 5.3.0
安装cmkake
略
安装opencv
步骤如开始部分。
添加环境变量
D:QtQt5.14.2Toolsmingw730_64in
D:QtQt5.14.25.14.2mingw73_64in
编译opencv
打开cmake
Where is the source code: D:opencvsources
where to build the binaries: D:opencv-build
点击 Configure,Yes，选择下列设定:
Specify the generator for this project: MinGW Makefiles
Specify native compilers, next
Compilers C: D:/Qt/Qt5.14.2/Tools/mingw730_64/bin/gcc.exe
Compilers C++: D:/Qt/Qt5.14.2/Tools/mingw730_64/bin/g++.exe
Finish
set Qt5_DIR to D:Qt5.9mingw53_32libcmakeQt5
Check the box [X]WITH_QT
Check the box [X]WITH_OPENGL
点config
Set QT_MAKE_EXECUTABLE to D:Qt5.9mingw53_32inqmake.exe
Set Qt5Concurrent_DIR to D:Qt5.9mingw53_32libcmakeQt5Concurrent
Set Qt5Core_DIR to D:Qt5.9mingw53_32libcmakeQt5Core
Set Qt5Gui_DIR to D:Qt5.9mingw53_32libcmakeQt5Gui
Set Qt5Test_DIR to D:Qt5.9mingw53_32libcmakeQt5Test
Set Qt5Widgets_DIR to D:Qt5.9mingw53_32libcmakeQt5Widgets
Set Qt5OpenGL_DIR to D:Qt5.9mingw53_32libcmakeQt5OpenGL
Set CMAKE_BUILD_TYPE to Release or RelWithDebInfo
Set OPENCV_VS_VERSIONINFO_SKIP=1
Uncheck the box []ENABLE_PRECOMPILED_HEADERS
点config
点generate
然后编译：
d:
cd d:
cd opencv-build
mingw32-make -j 8
mingw32-make install
mingw32-make -j 8时如果编译出错：
gcc: error: long: No such file or directory
C:mingw64inwindres.exe: preprocessing failed.
mingw32-make[2]: *** [modulescoreCMakeFilesopencv_core.diruild.make:1506: modules/core/CMakeFiles/opencv_core.dir/vs_version.rc.obj] Error 1
mingw32-make[2]: *** Waiting for unfinished jobs....
mingw32-make[1]: *** [CMakeFilesMakefile2:2237: modules/core/CMakeFiles/opencv_core.dir/all] Error 2
mingw32-make: *** [Makefile:179: all] Error 2
解决方法，在cmake选项中取消该选项：
Uncheck the box []OPENCV_ENABLE_ALLOCATOR_STATS
添加Opencv编译库到环境变量
D:opencv-buildinstallx86mingwin
测试
.pro文件中添加,注意修改文件路径和库名：
INCLUDEPATH += D:opencvuildinclude
LIBS += D:opencv-buildinlibopencv_*.dll
#LIBS += D:opencv-buildinlibopencv_core320.dll
#LIBS += D:opencv-buildinlibopencv_highgui320.dll
#LIBS += D:opencv-buildinlibopencv_imgcodecs320.dll
#LIBS += D:opencv-buildinlibopencv_imgproc320.dll
#LIBS += D:opencv-buildinlibopencv_features2d320.dll
#LIBS += D:opencv-buildinlibopencv_calib3d320.dll
# more correct variant, how set includepath and libs for mingw
# add system variable: OPENCV_SDK_DIR=D:/opencv/opencv-build/install
# read http://doc.qt.io/qt-5/qmake-variable-reference.html#libs
#INCLUDEPATH += $$(OPENCV_SDK_DIR)/include
#LIBS += -L$$(OPENCV_SDK_DIR)/x86/mingw/lib
# -lopencv_core320
# -lopencv_highgui320
# -lopencv_imgcodecs320
# -lopencv_imgproc320
# -lopencv_features2d320
# -lopencv_calib3d320
main.cpp
#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>
int main()
{
// read an image
cv::Mat image = cv::imread("C://Users//Administrator//Desktop//timg.jpg", 1);
// create image window named "My Image"
cv::namedWindow("My Image");
// show the image on window
cv::imshow("My Image", image);
cv::waitKey(0);
return 0;
}
MAC+Qt
Mac下只能使用Xcode进行构建。
可以使用brew install opencv进行安装opencv，但是github总是被墙，因此使用码云上的opencv源码来构建opencv。
下载opencv源码，打开cmake:
Where is the source code: /Users/cdq/thirdLibrary/opencv
where to build the binaries: /Users/cdq/thirdLibrary/opencv-build
点击config
再点击config
点generate
cd /Users/cdq/thirdLibrary/opencv
make -j 8
sudo make install
安装后的位置是： /usr/local/include，/usr/local/lib，/usr/local/share和/usr/local/bin
.pro文件
INCLUDEPATH +=/usr/local/include/opencv4/
LIBS += /usr/local/lib/libopencv_*.dylib
#LIBS += /usr/local/lib/libopencv_core.dylib
#LIBS += /usr/local/lib/libopencv_highgui.dylib
#LIBS += /usr/local/lib/libopencv_imgcodecs.dylib
#LIBS += /usr/local/lib/libopencv_imgproc.dylib
main.cpp文件
#include <QApplication>
#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <opencv2/opencv.hpp>
using namespace cv; //包含cv命名空间
int main( )
{
Mat srcImage = imread("/Users/cdq/Desktop/124.jpg"); //载入图像
imshow("【原始图】",srcImage);//显示图像
waitKey(0);//按任意键退出
return 0;
}
需要注意的是：运行成功后，图片总是以最小化显示，而不是直接弹出，导致我一度以为没有正常运行！
参考链接：
https://wiki.qt.io/How_to_setup_Qt_and_openCV_on_Windows
https://blog.csdn.net/duwangthefirst/article/details/79452314
https://blog.csdn.net/maizousidemao/article/details/81474834
https://blog.csdn.net/u012435142/article/details/82952302