OpenCV-4.0.0在Ubuntu16.04 64位中的安装
步骤一：安装必要的库
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
步骤二：下载opencv和opencv_contrib的源代码
cd ~/work/opencv-4.0
git clone https://github.com/opencv/opencv.git
git clone https://github.com/opencv/opencv_contrib.git
步骤三：建立build文件夹并设置设置cmake的编译指令，这里采用支持python3的OpenCVIDE选择，IDE选择使用Qtcreator
cd ~/work/opencv-4.0/opencv-4.0.0
mkdir build
cd build
sudo apt-get install qtcreator
sudo apt-get install python3-pip
sudo pip3 install numpy
步骤四：检查各个文件是否在路径下
cmake -D CMAKE_BUILD_TYPE=Release -D CMAKE_INSTALL_PREFIX=/usr/local
-D OPENCV_EXTRA_MODULES_PATH=~/work/opencv-4.0/opencv_contrib-4.0.0/modules
-D PYTHON3_EXECUTABLE=/usr/bin/python3
-D PYTHON_INCLUDE_DIR=/usr/include/python3.5
-D PYTHON_INCLUDE_DIR2=/usr/include/x86_64-linux-gnu/python3.5m
-D PYTHON_LIBRARY=/usr/lib/x86_64-linux-gnu/libpython3.5m.so
-D PYTHON3_NUMPY_INCLUDE_DIRS=~/.local/lib/python3.5/site-packages/numpy/core/include/
..
步骤五：编译
make -j2
步骤六：安装
sudo make install
步骤七：首先将OpenCV库添加到路径让系统可以找到，执行以下操作即可
sudo gedit /etc/ld.so.conf.d/opencv.conf
sudo ldconfig
步骤八：配置bash和pkg-config
sudo gedit /etc/bash.bashrc
在末尾添加：
PKG_CONFIG_PATH=$PKG_CONFIG_PATH:/usr/local/lib/pkgconfig
export PKG_CONFIG_PATH
保存退出，然后执行下面的命令使得配置生效：
source /etc/bash.bashrc
可使用下属命令查看安装的opencv的版本号：
pkg-config --modversion opencv
步骤九：安装python-opencv，并测试opencv是否安装成功
方法一：
cd ../samples/cpp/example_camke
cmake .
make
./opencv_example
程序运行成功，即可调起笔记本自带的摄像头
方法二：
pip3 install python-opencv
python3
import cv2
cv2.__version__
步骤十：qtcreator中opencv的pro文件配置
QT += core
QT -= gui
QMAKE_CXXFLAGS += -std=c++11
OR
CONFIG += c++11 #opencv需要C++11支持
TARGET = opencv_test
CONFIG += console
CONFIG -= app_bundle
TEMPLATE = app
\
SOURCES += main.cpp
INCLUDEPATH += /usr/local/include \
/usr/local/include/opencv \
/usr/local/include/opencv2
LIBS += /usr/local/lib/libopencv_aruco.so.4.0 \
/usr/local/lib/libopencv_bgsegm.so.4.0 \
/usr/local/lib/libopencv_bioinspired.so.4.0 \
/usr/local/lib/libopencv_calib3d.so.4.0 \
/usr/local/lib/libopencv_ccalib.so.4.0 \
/usr/local/lib/libopencv_core.so.4.0 \
/usr/local/lib/libopencv_datasets.so.4.0 \
/usr/local/lib/libopencv_dnn_objdetect.so.4.0 \
/usr/local/lib/libopencv_dnn.so.4.0 \
/usr/local/lib/libopencv_dpm.so.4.0 \
/usr/local/lib/libopencv_face.so.4.0 \
/usr/local/lib/libopencv_features2d.so.4.0 \
/usr/local/lib/libopencv_flann.so.4.0 \
/usr/local/lib/libopencv_freetype.so.4.0 \
/usr/local/lib/libopencv_fuzzy.so.4.0 \
/usr/local/lib/libopencv_hfs.so.4.0 \
/usr/local/lib/libopencv_highgui.so.4.0 \
/usr/local/lib/libopencv_imgcodecs.so.4.0 \
/usr/local/lib/libopencv_img_hash.so.4.0 \
/usr/local/lib/libopencv_imgproc.so.4.0 \
/usr/local/lib/libopencv_line_descriptor.so.4.0 \
/usr/local/lib/libopencv_ml.so.4.0 \
/usr/local/lib/libopencv_objdetect.so.4.0 \
/usr/local/lib/libopencv_optflow.so.4.0 \
/usr/local/lib/libopencv_phase_unwrapping.so.4.0 \
/usr/local/lib/libopencv_photo.so.4.0 \
/usr/local/lib/libopencv_plot.so.4.0 \
/usr/local/lib/libopencv_reg.so.4.0 \
/usr/local/lib/libopencv_rgbd.so.4.0 \
/usr/local/lib/libopencv_saliency.so.4.0 \
/usr/local/lib/libopencv_shape.so.4.0 \
/usr/local/lib/libopencv_stereo.so.4.0 \
/usr/local/lib/libopencv_stitching.so.4.0 \
/usr/local/lib/libopencv_structured_light.so.4.0 \
/usr/local/lib/libopencv_superres.so.4.0 \
/usr/local/lib/libopencv_surface_matching.so.4.0 \
/usr/local/lib/libopencv_text.so.4.0 \
/usr/local/lib/libopencv_tracking.so.4.0 \
/usr/local/lib/libopencv_videoio.so.4.0 \
/usr/local/lib/libopencv_video.so.4.0 \
/usr/local/lib/libopencv_videostab.so.4.0 \
/usr/local/lib/libopencv_xfeatures2d.so.4.0 \
/usr/local/lib/libopencv_ximgproc.so.4.0 \
/usr/local/lib/libopencv_xobjdetect.so.4.0 \
/usr/local/lib/libopencv_xphoto.so.4.0 \
/usr/local/lib/libopencv_aruco.so.4.0 \
`
ps：
在步骤三这里numpy可能sudo pip3 install numpy安装报错如下：
```cpp
The directory '/home/ds/.cache/pip/http' or its parent directory is not owned by the current user and the cache has been disabled. Please check the permissions and owner of that directory. If executing pip with sudo, you may want sudo's -H flag.
The directory '/home/ds/.cache/pip' or its parent directory is not owned by the current user and caching wheels has been disabled. check the permissions and owner of that directory. If executing pip with sudo, you may want sudo's -H flag.
Collecting numpy
Downloading https://files.pythonhosted.org/packages/52/e6/1715e592ef47f28f3f50065322423bb75619ed2f7c24be86380ecc93503c/numpy-1.18.1-cp35-cp35m-manylinux1_x86_64.whl (19.9MB)
4% |█▌ | 952kB 7.3kB/s eta 0:43:31Exception:
Traceback (most recent call last):
File "/usr/share/python-wheels/urllib3-1.13.1-py2.py3-none-any.whl/urllib3/response.py", line 226, in _error_catcher
yield
File "/usr/share/python-wheels/urllib3-1.13.1-py2.py3-none-any.whl/urllib3/response.py", line 301, in read
data = self._fp.read(amt)
File "/usr/share/python-wheels/CacheControl-0.11.5-py2.py3-none-any.whl/cachecontrol/filewrapper.py", line 49, in read
data = self.__fp.read(amt)
File "/usr/lib/python3.5/http/client.py", line 458, in read
n = self.readinto(b)
File "/usr/lib/python3.5/http/client.py", line 498, in readinto
n = self.fp.readinto(b)
File "/usr/lib/python3.5/socket.py", line 575, in readinto
return self._sock.recv_into(b)
File "/usr/lib/python3.5/ssl.py", line 929, in recv_into
return self.read(nbytes, buffer)
File "/usr/lib/python3.5/ssl.py", line 791, in read
return self._sslobj.read(len, buffer)
File "/usr/lib/python3.5/ssl.py", line 575, in read
v = self._sslobj.read(len, buffer)
socket.timeout: The read operation timed out
During handling of the above exception, another exception occurred:
解决办法：
第一步：先从地址下载.whl文件
https://files.pythonhosted.org/packages/52/e6/1715e592ef47f28f3f50065322423bb75619ed2f7c24be86380ecc93503c/numpy-1.18.1-cp35-cp35m-manylinux1_x86_64.whl
第二步：执行如下指令
sudo pip3 install numpy-1.18.1-cp35-cp35m-manylinux1_x86_64.whl
第三步：测试numpy，执行如下指令
python3
至此，numpy安装成功。