Gtk-Message: 09:56:19.551: Failed to load module "canberra-gtk-module"

解决办法

cmake
make
....
[100%] Built target opencv_example
admin@ub:~/opencv/samples/cpp/example_cmake/build$ ./opencv_example 
Built with OpenCV 4.6.0
Capture is opened
Gtk-Message: 09:56:19.551: Failed to load module "canberra-gtk-module"
sudo apt-get install libcanberra-gtk-module
./opencv_example 
Built with OpenCV 4.6.0
Capture is opened
^C

成功！
这是黎明前最后个问题，故放在前面。

以下是查看 history 复盘 Ubuntu 20.04 install OpenCV 4.7.0后改为4.6.0。
个人总结，非保姆级教程，最新最详细看向日葵骑士Faraday原创的Ubuntu18.04安装Opencv4.5(最新最详细)。虽然我是中途参考，但获益良多。

自动与手动 an 装

标题很吸引，但自动与手动an装均未成功，事后发现一处错误，原帖（看这篇就够了——opencv与libopencv与cv_bridge的安装与使用）里验证opencv是否安装

pkg-config --modversion opencv

在我电脑上验证

admin@ub:~/opencv$ pkg-config --modversion opencv
Package opencv was not found in the pkg-config search path.
Perhaps you should add the directory containing `opencv.pc'
to the PKG_CONFIG_PATH environment variable
No package 'opencv' found
admin@ub:~/opencv$ pkg-config --modversion opencv4
4.6.0

这部分是失败的循环。

在linux中， ldd是list, dynamic, dependencies的缩写， 列出动态库依赖关系。

  475  ./camera
  476  cat ../README.md 
  477  ldd camera
  478  sudo aptitude install opencv
  479  locate libopencv_highgui
  480  sudo find / -name "libopencv_highgui"
  481  sudo aptitude install opencv
  482  sudo aptitude install libopencv-highgui-dev
  483  ./camera
  484  ldd camera
  485  sudo find / -name "libopencv_highgui"
  486  su
  487  sudo aptitude install python3
  488  python3
  489  ./camera
  490  ldd camera
  498  ./camera
  499  sudo aptitude install libopencv-dev
  505  sudo aptitude install ros-noetic-cv-bridge
  506  ldd camera
  507  ./camera
  508  ldd camera
  509  sudo find / -name "libopencv_core.406"
  510  su
  511  pkg-config --modversion opencv
  512  sudo apt-get install libopencv-highgui-dev
  523  ldd camera
  524  ldd gtk2.0-dev

运行./camera 命令时，报错缺少libopencv_highgui.so.3.2，ldd 查看依赖。

admib@ub:~$ ldd camera
	linux-vdso.so.1 (0x00007fff1fb4e000)
	libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007f419ad0c000)
	libopencv_highgui.so.3.2 => not found
	libopencv_videoio.so.3.2 => not found
	libopencv_imgcodecs.so.3.2 => not found
	libopencv_imgproc.so.3.2 => not found
	libopencv_core.so.3.2 => not found
	libstdc++.so.6 => /usr/lib/x86_64-linux-gnu/libstdc++.so.6 (0x00007f419a983000)
	libcudart.so.9.0 => /usr/local/cuda-9.0/lib64/libcudart.so.9.0 (0x00007f419a716000)
	libcublas.so.9.0 => /usr/local/cuda-9.0/lib64/libcublas.so.9.0 (0x00007f41972e0000)
	libcurand.so.9.0 => /usr/local/cuda-9.0/lib64/libcurand.so.9.0 (0x00007f419337c000)
	libcudnn.so.7 => /usr/local/cuda-9.0/lib64/libcudnn.so.7 (0x00007f41805f6000)
	libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1 (0x00007f41803de000)
	libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007f41801bf000)
	libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f417fdce000)
	/lib64/ld-linux-x86-64.so.2 (0x00007f419b478000)
	libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007f417fbca000)
	librt.so.1 => /lib/x86_64-linux-gnu/librt.so.1 (0x00007f417f9c2000)

以上代码选自问题解决：运行./darknet命令时，报错缺少libopencv_highgui.so.3.2包，不想折腾或首次an装看上文保姆教程。

官网教程

获取源码

OpenCV官网地址OpenCVReleases
OpenCVTutorials，注意Opencv的版本号。

Cmake 手动编译 Opencv

复习常用解压缩命令

tar -zcvf
tar -zxvf
gzip 
gzip -d 
zip
unzip

这部分是参考官网Quick start
Build core modules，Installation in Linux 。

# Install minimal prerequisites (Ubuntu 18.04 as reference)
sudo apt update && sudo apt install -y cmake g++ wget unzip
# Download and unpack sources
wget -O opencv.zip https://github.com/opencv/opencv/archive/4.x.zip
unzip opencv.zip
# Create build directory
mkdir -p build && cd build
# Configure
cmake  ../opencv-4.x
# Build
cmake --build .

这部分官网教程不适合排查问题，可能一处错误后面无法进行。

  526  cd ../../
  527  ls 
  528  gzip opencv-4.7.0.zip 
  529  ls
  530  gzip -d opencv-4.7.0.zip.gz 
  531  ls
  532  zip -help
  533  zip -A opencv-4.7.0.zip 
  534  unzip opencv-4.7.0.zip 
  535  ls
  536  cd opencv-4.7.0/
  537  ls 
  538  cd cmake/
  539  ls
  540  cd ../../
  541  ls
  542  mv opencv-4.7.0 /usr/local/
  543  su 
  544  sudo aptitude install g++
  545  cmake -v
  546  sudo aptitude install cmake
  547  wget
  548  wget -v
  549  cd /usr/lib
  550  ls
  551  cd ../local/
  552  ls
  553  cd opencv-4.7.0/
  554  ls
  555  mkdir build
  556  ls
  557  cd build/
  558  cmake ../../opencv-4.7.0/
  559  cd ../../
  560  ls
  561  mv opencv-4.7.0/build/ ./
  562  su
  563  ls
  564  cmake --build ./
  565  su 
  566  cd opencv-4.7.0/
  567  ls
  568  cmake --build ./
  569  su
  570  cd ../
  571  ls
  572  cmake build/ .
  573  rm -rf build/
  574  su
  575  sudo aptitude update && sudo aptitude upgrade
  576  cd opencv-4.7.0/samples/cpp/
  577  ls
  578  cd example_cmake/
  579  ls
  580  cd build/
  581  ls
  582  ./opencv_example 
  583  sudo aptitude install libgtk2.0-dev
  584  cd ../../../
  585  cd ../
  586  ls
  587  cd modules/
  588  ls
  589  cd highgui/src/
  590  ls
  591  cd ../../../
  592  pip uninstall opencv-python
  593  opencv-python
  594  sudo aptitude install python3-pip
  595  pip uninstall opencv-python
  596  pip install opencv-contrib-python
  597  pip uninstall opencv-python
  598  sudo aptitude install libgtk2.0-dev
  599  cd /etc/
  600  ls
  601  file apt/
  602  cd apt/
  603  ls
  604  gedit sources.list
  605  ls -l sources.list

重新编译链接 4.6.0

这部分发现一处错误，向日葵骑士Faraday原创的Ubuntu18.04安装Opencv4.5(最新最详细)

cmake -D CMAKE_INSTALL_PREFIX=/usr/local -D CMAKE_BUILD_TYPE=Release -D OPENCV_GENERATE_PKGCONFIG=ON -D   -D OPENCV_ENABLE_NONFREE=True ..

报错信息为

admin@ub:~/opencv/build$ cmake -D CMAKE_INSTALL_PREFIX=/usr/local -D CMAKE_BUILD_TYPE=Release -D OPENCV_GENERATE_PKGCONFIG=ON -D   -D OPENCV_ENABLE_NONFREE=True ..
Parse error in command line argument: -D
Should be: VAR:type=value
CMake Error: No cmake script provided.
CMake Error: Problem processing arguments. Aborting.

admin@ub:~/opencv/build$ cmake -D CMAKE_INSTALL_PREFIX=/usr/local -D CMAKE_BUILD_TYPE=Release -D OPENCV_GENERATE_PKGCONFIG=ON  -D OPENCV_ENABLE_NONFREE=True ..
-- The CXX compiler identification is GNU 9.4.0
-- The C compiler identification is GNU 9.4.0
-- Check for working CXX compiler: /usr/bin/c++
-- Check for working CXX compiler: /usr/bin/c++ -- works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Check for working C compiler: /usr/bin/cc
-- Check for working C compiler: /usr/bin/cc -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
.......
-- Configuring done
-- Generating done
-- Build files have been written to: .....
admin@ub:~/opencv/build$ sudo make -j12

经历漫长编译、链接后

  606  su
  607  cd ../
  608  cd build/
  609  rm -rf *
  610  cmake -D CMAKE_INSTALL_PREFIX=/usr/local -D CMAKE_BUILD_TYPE=Release -D OPENCV_GENERATE_PKGCONFIG=ON -D   -D OPENCV_ENABLE_NONFREE=True ..
  611  cmake -D CMAKE_INSTALL_PREFIX=/usr/local -D CMAKE_BUILD_TYPE=Release -D OPENCV_GENERATE_PKGCONFIG=ON  -D OPENCV_ENABLE_NONFREE=True ..
  612  sudo make -j12
  613  sudo make install
  614  sudo gedit /etc/bash.bashrc
  615  souce /etc/bash.bashrc 
  616  source /etc/bash.bashrc 
  617  #打开下列文件
  618  sudo gedit /etc/ld.so.conf.d/opencv.conf 
  619  # 添加lib路經 在 末尾 保存退出
  620  /usr/local/lib
  621  # 更新
  622  sudo ldconfig
  623  pkg-config --modversion opencv4
  624  pkg-config --libs opencv4
  625  cd ../
  626  cd samples/cpp/example_cmake/
  627  mkdir build
  628  cd build/
  629  cmake ..
  630  make
  631  ./opencv_example 
  632  pwd
  633  sudo apt-get install libcanberra-gtk-module
  634  ls
  635  ./opencv_example 
  636  history

以上。