openCV3.4.1 ubuntu16

• GCC 4.4.x or later

• CMake 2.6 or higher

• Git

• GTK+2.x or higher, including headers (libgtk2.0-dev) # 控制opencv GUI

• pkg-config

• Python 2.6 or later and Numpy 1.5 or later with developer packages (python-dev, python-numpy)

• ffmpeg or libav development packages: libavcodec-dev, libavformat-dev, libswscale-dev

• [optional] libtbb2 libtbb-dev

• [optional] libdc1394 2.x

• [optional] libjpeg-dev, libpng-dev, libtiff-dev, libjasper-dev, libdc1394-22-dev

$ sudo apt-get install build-essential
$ sudo apt-get install cmake git libgtk2.0-dev pkg-config libavcodec-dev libavformat-dev libswscale-dev
$ sudo apt-get install python-dev python-numpy libtbb2 libtbb-dev libjpeg-dev libpng-dev libtiff-dev libjasper-dev libdc1394-22-dev # 处理图像所需的包
$ sudo apt-get install libavcodec-dev libavformat-dev libswscale-dev libv4l-dev
$ sudo apt-get install libxvidcore-dev libx264-dev # 处理视频所需的包
$ sudo apt-get install libatlas-base-dev gfortran # 优化opencv功能
$ sudo apt-get install ffmpeg 

自己安装得依赖包

sudo apt-get install build-essential  
sudo apt-get install cmake git libgtk2.0-dev pkg-config libavcodec-dev libavformat-dev libswscale-dev  
sudo apt-get install python-dev python-numpy libtbb2 libtbb-dev libjpeg-dev libpng-dev libtiff-dev libjasper-dev libdc1394-22-dev

出现类似问题及解决方法:
问题： /sbin/ldconfig.real: /usr/local/cuda-8.0/targets/x86_64-linux/lib/libcudnn.so.6 is not a symbol link

sudo ldconfig -v
找到这一行错误：libcudnn.so.6 -> libcudnn.so.6.0.21

ubuntu下面ctrl+shift+F可以查找命令窗中得显示内容

或者用命令：

dpkg -S /usr/local/cuda-8.0/targets/x86_64-linux/lib/libcudnn.so.6

解决问题代码：

sudo ln -sf /usr/local/cuda-8.0/targets/x86_64-linux/lib/libcudnn.so.4.0.21 /usr/local/cuda-8.0/targets/x86_64-linux/lib/libcudnn.so.6

下载地址： https://opencv.org/releases.html

进入下载好得解压文件夹当中，创建一个新的文件夹：

mkdir build
cd build

cmake -D:= 添加变量及值到CMakeCache.txt，注意这个后面得两个点不能省略

cmake -D CMAKE_BUILD_TYPE=RELEASE -D CMAKE_INSTALL_PREFIX=/usr/local ..

编译+安装：

sudo make #make -j4表示四核并行安装
sudo make install

将opencv的库添加到本地路径：

sudo gedit /etc/ld.so.conf.d/opencv.conf
文件中加入内容： /usr/local/lib
sudo ldconfig

法二：

sudo /bin/bash -c 'echo "/usr/local/lib" > /etc/ld.so.conf.d/opencv.conf'
sudo ldconfig

配置bash文件

sudo gedit /etc/bash.bashrc
末尾配置如下：
PKG_CONFIG_PATH=$PKG_CONFIG_PATH:/usr/local/lib/pkgconfig
export PKG_CONFIG_PATH
生效：
source /etc/bash.bashrc
更新：
sudo updatedb

安装完成测试：
找到下载好的解压包的opencv文件，我的位置是在 opencv-3.4.1/samples/cpp/example_cmake，
在这个文件目录下面有make文件，所以执行

cmake .
make
./opencv_example
即可看到打开了摄像头，在左上角有一个hello opencv ，表示配置成功

法二：
在这里，要在下面打开的这个文件夹中添加CMakeLists.txt和Makefile文件，这里对其做如下修改：（以下的说明都是根据经验得来，没有经过严格求证，如有错误，麻烦指正，谢谢）
CMakeLists.txt

# cmake needs this line
cmake_minimum_required(VERSION 2.8)

# Define project name
project(opencv_example_project)

# Find OpenCV, you may need to set OpenCV_DIR variable
# to the absolute path to the directory containing OpenCVConfig.cmake file
# via the command line or GUI
find_package(OpenCV REQUIRED)

# If the package has been found, several variables will
# be set, you can find the full list with descriptions
# in the OpenCVConfig.cmake file.
# Print some message showing some of them
message(STATUS "OpenCV library status:")
message(STATUS "    version: ${OpenCV_VERSION}")
message(STATUS "    libraries: ${OpenCV_LIBS}")
message(STATUS "    include path: ${OpenCV_INCLUDE_DIRS}")

if(CMAKE_VERSION VERSION_LESS "2.8.11")
  # Add OpenCV headers location to your include paths
  include_directories(${OpenCV_INCLUDE_DIRS})
endif()

# Declare the executable target built from your sources
add_executable(display_image display_image.cpp) #第一个是为自己生成的目标执行文件命名 第二个变量是需要make的cpp的名字

# Link your application with OpenCV libraries
target_link_libraries(display_image ${OpenCV_LIBS}) #替换成自己的执行文件的名称就可以了，与上面的add_executable的第一个名称相同

Makefile（在这个文件中相应修改的未知就是all：执行文件的名字，下一行：执行文件名字：编译文件的名字.o, clean： 编译额外那件的名字.o 执行文件名字

CXX ?= g++

CXXFLAGS += -c -Wall $(shell pkg-config --cflags opencv)
LDFLAGS += $(shell pkg-config --libs --static opencv)

all: display_image

display_image: display_image.o; $(CXX) $< -o $@ $(LDFLAGS)

%.o: %.cpp; $(CXX) $< -o $@ $(CXXFLAGS)

clean: ; rm -f display_image.o display_image

cd ~/opencv-3.4.0/samples/cpp/tutorial_code/introduction/display_image
cmake .
make
./display_image ~/opencv-3.4.0/samples/data/lena.jpg

参考文献：
https://blog.csdn.net/yudiemiaomiao/article/details/72780790
https://blog.csdn.net/qq_24626557/article/details/70173399
https://blog.csdn.net/langb2014/article/details/54376716
https://blog.csdn.net/cocoaqin/article/details/78163171