This article adopts the environment: Ubuntu14.04 + OpenCV-3.4.0
Compatible with OpenCV-2.4.xxx OpenCV-3.xx
1. Source code preparation: opencv, cmake
1. Opencv official website https://opencv.org/ Download source package: opencv-3.4.0.tar.gz
2. Cmake official website https://cmake.org/ Download source package: cmake-3.10.2.tar.gz
2. Install cmake
1. Unzip the source code and enter the unzipped directory
$ tar -zxvf cmake-3.10.2.tar.gz
$ cd cmake-3.10.2
2. Read the README.rst document and follow the instructions:
Interpretation: First, you must have a C++ compiler, and you must support the C++11 standard (the g++ version is too low, it will cause errors, please upgrade yourself); then run the $ ./bootstrap script to configure, you can use some items such as "--help ", "--prefix" (installation directory); After bootstrap is successful, execute $ make $ make install.
In short, just three commands:
$ ./bootstrap
$ make
$ sudo make install
After the installation is complete, check:
$ cmake --version
Get it, it's that simple.
PS: It is said that there is a simpler and cruder method:
$ sudo apt-get install cmake
3. Install the dependency library
$ sudo apt-get install build-essential libgtk2.0-dev libavcodec-dev libavformat-dev libjpeg-dev libtiff4-dev libswscale-dev libjasper-dev
Fourth, install Opencv
1. Unzip the source code and enter the unzipped directory
$ tar -zxvf opencv-3.4.0.tar.gz
$ cd opencv-3.4.0
2. Create a compilation folder build and enter build
$ mkdir build
$cd build
3. Execute the following command, CMAKE_INSTALL_PREFIX=path, "..": CMakeLists.txt path (in decompressed opencv)
$ cmake -D CMAKE_BUILD_TYPE=Release -D CMAKE_INSTALL_PREFIX=/usr/local ..
In this step, something went wrong in version 3.2.0, and the following error will occur:
-- ICV: Downloading ippicv_linux_20151201.tgz...
CMake Error at 3rdparty/ippicv/downloader.cmake:73 (file):
file DOWNLOAD HASH mismatch
for file: [/root/library/opencv/opencv-3.2.0/3rdparty/ippicv/downloads/linux-808b791a6eac9ed78d32a7666804320e/ippicv_linux_20151201.tgz]
expected hash: [808b791a6eac9ed78d32a7666804320e]
actual hash: [d41d8cd98f00b204e9800998ecf8427e]
status: [1;"Unsupported protocol"]
Call Stack (most recent call first):
3rdparty/ippicv/downloader.cmake:110 (_icv_downloader)
cmake/OpenCVFindIPP.cmake:243 (include)
cmake/OpenCVFindLibsPerf.cmake:37 (include)
CMakeLists.txt:558 (include)
CMake Error at 3rdparty/ippicv/downloader.cmake:77 (message):
ICV: Failed to download ICV package: ippicv_linux_20151201.tgz.
Status=1;"Unsupported protocol"
Call Stack (most recent call first):
3rdparty/ippicv/downloader.cmake:110 (_icv_downloader)
cmake/OpenCVFindIPP.cmake:243 (include)
cmake/OpenCVFindLibsPerf.cmake:37 (include)
CMakeLists.txt:558 (include)
-- Configuring incomplete, errors occurred!
See also "/root/library/opencv/opencv-3.2.0/build/CMakeFiles/CMakeOutput.log".
See also "/root/library/opencv/opencv-3.2.0/build/CMakeFiles/CMakeError.log".
Baidu checked it: it needs to be downloaded during the installation of opencv . Due to network reasons, this file often fails to download.ippicv_linux_20151201.tgz
Solution:
1. Manually download ippicv_linux_20151201.tgz ; you can Baidu, a lot.
2. Create opencv-3.2.0/3rdparty/ippicv/downloads/linux-808b791a6eac9ed78d32a7666804320e/ directory
Don't copy! ! ! The directory is selected and created according to the output error information, as above: (so many lines of error information are deliberately posted, just to illustrate this point)
for file: [/root/library/opencv/opencv-3.2.0/3rdparty/ippicv/downloads/linux-808b791a6eac9ed78d32a7666804320e/ippicv_linux_20151201.tgz]
3. Put the downloaded file in this directory;
4. Re-execute the cmake command.
4. Compile (unknown error: Ubuntu1204 error, 1404 is normal; guess it may be the version of the dependent library)
$ make
5. Installation
$ make install
6. Configure the environment variables of opencv
$ vi /etc/ld.so.conf.d/opencv.conf (file or empty, newly created)
Add: /usr/ local /lib
$ ldconfig //make it effective
7. Configure bash
$ vi /etc/bash.bashrc
Add the following two lines at the end of the text:
PKG_CONFIG_PATH=$PKG_CONFIG_PATH:/usr/local/lib/pkgconfig
export PKG_CONFIG_PATH
$ source /etc/bash.bashrc //make it effective
5. Test
Use the built-in test case, under samples/cpp/example_cmake
If you are interested, you can read how CMakeLists.txt is written under example_cmake, and there are a lot of comments in it.
$ cmake . $ make
$ ./opencv_example
1. No camera environment:
Built with OpenCV 3.4.0
No capture
2. With camera environment:
Built with OpenCV 3.4.0
Capture is opened
select timeout
select timeout
OpenCV Error: Assertion failed (total() == 0 || data != __null) in Mat, file /root/library/opencv/opencv-3.4.0/modules/core/include/opencv2/core/mat.inl.hpp, line 500
terminate called after throwing an instance of 'cv::Exception'
what(): /root/library/opencv/opencv-3.4.0/modules/core/include/opencv2/core/mat.inl.hpp:500: error: (-215) total() == 0 || data != __null in function Mat
Abandoned (core dumped)
Error in operation: Timeout to open camera! ! !
Haven't found the reason yet, put it aside for now.
This problem has been solved, see [ Virtual machine Ubuntu fails to open the camera and OpenCV opens the camera overtime ]! ! !
The effect after solving the problem:
Afterword:
Opencv is installed, the next part will start to write the first opencv project.
Remarks: Refer to the blog http://blog.csdn.net/cocoaqin/article/details/78163171