opencv编译安装

1.通过github下载源码：

git clone https://github.com/opencv/opencv.git

2.新建编译目录：

mkdir build && cd build

3.通过cmake创建makefile并指定编译安装位置：

cmake .. -DCMAKE_BUILD_TYPE=Release  -DCMAKE_INSTALL_PREFIX=/home/ubuntu/opt/opencv

4.编译并安装:

make -j8 && make install 

5.设置环境变量

vi ~/.bashrc

export PATH=//home/ubuntu/opt/opencv/bin:$PATH

6.编译报错排查

①cmake时使用如下指令：

cmake .. -DCMAKE_BUILD_TYPE=RELEASE -DWITH_TBB=ON -DBUILD_NEW_PYTHON_SUPPORT=ON -DWITH_V4L=ON -DWITH_VTK=ON -DCMAKE_INSTALL_PREFIX=/home/ubuntu/opt/opencv

指令中开启了TBB这个变量，编译时报错：

make[2]: *** No rule to make target '/usr/lib/libtbb.so', needed by 'lib/libopencv_core.so.3.4.1'.  Stop.
make[2]: *** Waiting for unfinished jobs....
[ 38%] Building CXX object modules/core/CMakeFiles/opencv_core.dir/stat.avx2.cpp.o
CMakeFiles/Makefile2:1467: recipe for target 'modules/core/CMakeFiles/opencv_core.dir/all' failed
make[1]: *** [modules/core/CMakeFiles/opencv_core.dir/all] Error 2
Makefile:160: recipe for target 'all' failed

make: *** [all] Error 2

make clean之后重新cmake：

cmake .. -DCMAKE_BUILD_TYPE=Release  -DCMAKE_INSTALL_PREFIX=/home/ubuntu/opt/opencv

发现报错依旧，检查cmake生成的文件，-DWITH_TBB=ON取消之后的条件，生成文件并未取消，删除build下所有文件，重新cmake，问题解决。