ubuntu下多版本opencv安裝及在QT下配置

前言

本文旨在在ubuntu18.04下安裝opencv3.4.1及opencv4.3.0兩個版本，進行多版本配置切換，卸載，給出簡單的make構造的demo驗證安裝及qt下對opencv的引入示例。

OpenCV安裝

1. OpenCV源碼下載

2. 安裝命令

cd opencv-3.4.1; 
mkdir -p build/installed; cd build;
cmake -D CMAKE_BUILD_TYPE=RELEASE \
	  -D CMAKE_INSTALL_PREFIX=/home/city945/software/opencv-3.4.1/build/installed \
	  -D BUILD_TESTS=OFF \
	  -D OPENCV_GENERATE_PKGCONFIG=ON \
	  ..;
make -j8; 
sudo make install;

3. 參數解釋

  -D CMAKE_INSTALL_PREFIX 指定sudo make install 的安裝目錄，默認在/usr/local下，如果不改，安裝多個版本時，後一版本會覆蓋前面版本
  -D BUILD_TESTS=OFF 加快編譯速度 詳細瞭解 -> https://docs.opencv.org/4.3.0/d7/d9f/tutorial_linux_install.html
  -D OPENCV_GENERATE_PKGCONFIG=ON 針對opencv4，使其支持pkg-config

4. 驗證安裝

• 查詢opencv版本

pkg-config --modversion opencv
pkg-config --cflags opencv
pkg-config --libs opencv
# 注意對opencv4 是 pkg-config --modversion opencv4，可cd /home/city945/software/opencv4.3.0/build/installed/lib/pkgconfig/ 查看

• demo 驗證 demo源碼
  

多版本配置及切換

• .bashrc中控制

# 多版本opencv
# export PKG_CONFIG_PATH="/home/city945/software/opencv-3.4.1/build/installed/lib/pkgconfig"
# export LD_LIBRARY_PATH="/home/city945/software/opencv-3.4.1/build/installed/lib"
export PKG_CONFIG_PATH="/home/city945/software/opencv-4.3.0/build/installed/lib/pkgconfig"
export LD_LIBRARY_PATH="/home/city945/software/opencv-4.3.0/build/installed/lib"

• 卸載

cd build;
sudo make uninstall;
cd ..; rm -rf build;
# 安裝在/usr/local下的手動再把/usr/local/lib下的軟連接刪了

QT中引入opencv

• .pro

INCLUDEPATH += /home/city945/software/opencv-3.4.1/build/installed/include \
    /home/city945/software/opencv-3.4.1/build/installed/include/opencv \
    /home/city945/software/opencv-3.4.1/build/installed/include/opencv2

LIBS += /home/city945/software/opencv-3.4.1/build/installed/lib/libopencv*.so

參考

opencv-doc
Ubuntu下多版本OpenCV共存和切換

---

2020-07-05

• error while loading shared libraries: libopencv_core.so.3.4: cannot open shared object file: No such file or directory

sudo vim /etc/ld.so.conf.d/opencv.conf
# 文件中添加install/lib
/home/city945/software/opencv-3.4.1/build/installed/lib
sudo ldconfig