Linux下OpenCV的环境搭建

OpenCV is the most popular and advanced code library for Computer Vision related applications today, spanning from many very basic tasks (capture and pre-processing of image data) to high-level algorithms (feature extraction, motion tracking, machine learning). It is free software and provides a rich API in C, C++, Java and Python. Other wrappers are available. The library itself is platform-independent and often used for real-time image processing and computer vision.

1.移除先前安装的ffmpeg和x264

1 sudo apt-get -qq remove ffmpeg x264 libx264-dev

2.安装依赖项

1 sudo apt-get -qq install libopencv-dev build-essential checkinstall cmake pkg-config yasm libjpeg-dev libpng-dev libtiff5-dev libjasper-dev libavcodec-dev libavformat-dev libswscale-dev libdc1394-22-dev libxine-dev libgstreamer0.10-dev libgstreamer-plugins-base0.10-dev libv4l-dev python-dev python-numpy libtbb-dev libqt4-dev libgtk2.0-dev libfaac-dev libmp3lame-dev libopencore-amrnb-dev libopencore-amrwb-dev libtheora-dev libvorbis-dev libxvidcore-dev x264 v4l-utils ffmpeg cmake qt5-default checkinstall

有时会提示说，找不到ffmpeg软件包。

解决方法：

E: 软件包 gstreamer0.10-ffmpeg 没有可供安装的候选者

好吧，装不上来，因为在Ubuntu上gstreamer0.10-ffmpeg属于额外的版权受限程序，gstreamer0.10-ffmpeg包可通过一些第三方的PPA源，但是
所有您需要做的就是添加PPA到您的系统，更新本地存储索引和安装gstreamero.10-ffmpeg包。如下输入命令：

sudo add-apt-repository ppa:mc3man/trusty-media
sudo apt-get update
sudo apt-get install gstreamer0.10-ffmpeg
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作者：Jack_Kuo
来源：CSDN
原文：https://blog.csdn.net/weixin_37251044/article/details/78380303
版权声明：本文为博主原创文章，转载请附上博文链接！

3.下载并解压OpenCV

1 wget -O OpenCV-$version.zip http://sourceforge.net/projects/opencvlibrary/files/opencv-unix/$version/opencv-"$version".zip/download
2 unzip OpenCV-$version.zip
3 cd opencv-$version

4.编译源码，构建OpenCV

1 mkdir build
2 cd build
3 cmake -D CMAKE_BUILD_TYPE=RELEASE -D CMAKE_INSTALL_PREFIX=/usr/local -D WITH_TBB=ON -D BUILD_NEW_PYTHON_SUPPORT=ON -D WITH_V4L=ON -D INSTALL_C_EXAMPLES=ON -D INSTALL_PYTHON_EXAMPLES=ON -D BUILD_EXAMPLES=ON -D WITH_QT=ON -D WITH_OPENGL=ON ..
4 make -j2
5 sudo make install
6 sudo sh -c 'echo "/usr/local/lib" > /etc/ld.so.conf.d/opencv.conf'
7 sudo ldconfig

5.测试OpenCV是否安装成功

转到opencv的样例代码目录(samples/c)下,

1 chmod +x build_all.sh
2 ./build_all.sh
3 ./facedetect "/usr/share/opencv/haarcascades/haarcascade_frontalface_alt.xml" lena.jpg

 运行结果：

编译OpenCV程序：

 1 #!/bin/bash
 2 echo "compiling $1"
 3 if [[ $1 == *.c ]]
 4 then
 5     gcc -ggdb `pkg-config --cflags opencv` -o `basename $1 .c` $1 `pkg-config --libs opencv`;
 6 elif [[ $1 == *.cpp ]]
 7 then
 8     g++ -ggdb `pkg-config --cflags opencv` -o `basename $1 .cpp` $1 `pkg-config --libs opencv`;
 9 else
10     echo "Please compile only .c or .cpp files"
11 fi
12 echo "Output file => ${1%.*}"

 将上面代码保存成shell脚本，在每次编译程序时调用即可。

如果在编译过程中出现如下错误：

1 [ 14%] Building CXX object modules/core/CMakeFiles/opencv_core.dir/src/system.cpp.o
2   /home/test/autobuild/instance-0/output/build/opencv-2.4.10/modules/core/src/system.cpp: In function '(static initializers for /home/test/autobuild/instance-0/output/build/opencv-2.4.10/modules/core/src/system.cpp)':
3   /home/test/autobuild/instance-0/output/build/opencv-2.4.10/modules/core/src/system.cpp:280:10: error: inconsistent operand constraints in an 'asm'
4   make[3]: *** [modules/core/CMakeFiles/opencv_core.dir/src/system.cpp.o] Error 1

可参考：https://github.com/Itseez/opencv/commit/ea50be0529c248961e1b66293f8a9e4b807294a6

　　https://www.cnblogs.com/liushaobo/p/4373956.html