OpenCV静态库编译与链接

以OpenCV-4.0.0为例说明在Ubuntu环境下的静态库编译与链接方法：

1、编译配置

opencv依赖第三方的库，所以当把opencv编译成静态库的时候，注意要把它运行时必要的依赖库也编译进来，opencv源码内有自己的3rdparty，主要有：libjpeg、libpng、libtiff、libzlib、libwebp、libprotobuf、ffmpeg（用到video时编译）、libgtk（用于显示界面显示，服务器部署不会用到），可以通过cmake -LA来查看配置的编译信息，再根据信息考虑把opencv的哪些module编译进来。

cmake -DEXECUTABLE_OUTPUT_PATH:PATH=$(pwd) \
    -DCMAKE_BUILD_TYPE=RELEASE \
    -DCMAKE_INSTALL_PREFIX=/usr/local \
    -DBUILD_JASPER=ON \
    -DBUILD_JAVA=OFF \
    -DBUILD_JPEG=ON \           #编译opencv 3rdparty自带的libjpeg
    -DBUILD_PERF_TESTS=OFF \
    -DBUILD_PNG=ON \            #编译opencv 3rdparty自带的libpng
    -DBUILD_PROTOBUF=ON \       #编译opencv 3rdparty自带的libprotobuf
    -DBUILD_SHARED_LIBS=NO \    #编译成静态库
    -DBUILD_TESTS=OFF \
    -DBUILD_TIFF=ON \           #编译opencv 3rdparty自带的libtiff
    -DBUILD_ZLIB=ON \           #编译opencv 3rdparty自带的libzlib
    -DBUILD_WEBP=ON \           #编译opencv 3rdparty自带的libwebp
    -DBUILD_opencv_apps=OFF \
    -DBUILD_opencv_core=ON \
    -DBUILD_opencv_calib3d=ON \
    -DBUILD_opencv_dnn=ON \
    -DBUILD_opencv_features2d=ON \
    -DBUILD_opencv_flann=ON \
    -DBUILD_opencv_gapi=OFF \
    -DBUILD_opencv_highgui=ON \
    -DBUILD_opencv_imgcodecs=ON \
    -DBUILD_opencv_imgproc=ON \
    -DBUILD_opencv_java_bindings_generator=OFF \
    -DBUILD_opencv_js=OFF \
    -DBUILD_opencv_ml=ON \
    -DBUILD_opencv_objdetect=OFF \
    -DBUILD_opencv_photo=OFF \
    -DBUILD_opencv_python2=OFF \
    -DBUILD_opencv_python3=OFF \
    -DBUILD_opencv_python_bindings_generator=OFF \
    -DBUILD_opencv_stitching=OFF \
    -DBUILD_opencv_ts=OFF \
    -DBUILD_opencv_video=OFF \
    -DBUILD_opencv_videoio=OFF \
    -DWITH_GTK=OFF \
    -DWITH_GTK_2_X=OFF \
   -DWITH_LAPACK=OFF \

2、链接

链接时指定opencv的静态库以及依赖的库。另外需要注意头文件的问题，通过CMakeLists把opencv加入项目编译时，由于opencv编译完成后要install才会把所用的头文件集中拷贝到一个地方，所以事先将头文件拷贝到了项目的opencv目录下。

set(opencv_libs     #项目用到的库
    opencv_core
    opencv_dnn
    opencv_imgproc
    opencv_imgcodecs
    opencv_ml
    opencv_calib3d
    opencv_highgui
    zlib
    libjasper
    libjpeg-turbo
    libpng
    libtiff
    IlmImf
    libprotobuf
    libwebp)
 #编译opencv
 add_subdirectory(${CMAKE_SOURCE_DIR}/3rdparty/opencv-4.0.0) 
 #增加头文件路径
 include_directories(${CMAKE_SOURCE_DIR}/3rdparty/opencv-4.0.0/include)
 #链接opencv静态库
 target_link_libraries(demo ${opencv_libs} -lrt -lpthread)