ubuntu安装OpenCV 及遇到的问题

1. sudo apt-get install build-essential
2. sudo apt-get install cmake git libgtk2.0-dev pkg-config libavcodec-dev libavformat-dev libswscale-dev qtbase5-dev libtiff-dev
3. mkdir -p opencv-3.4.0 build
4. cd opencv-3.4.0/build
5. cmake -D CMAKE_BUILD_TYPE=RELEASE -D CMAKE_INSTALL_PREFIX=/usr/local -D WITH_CUDA=ON -D WITH_TBB=ON -D BUILD_NEW_PYTHON_SUPPORT=ON -D WITH_V4L=ON -D BUILD_EXAMPLES=ON -D WITH_OPENGL=ON -D ENABLE_FAST_MATH=1 -D CUDA_FAST_MATH=1 -D WITH_CUBLAS=1 -D WITH_NVCUVID:BOOL=1 -D WITH_GSTREAMER=ON -D WITH_FFMPEG=ON -D WITH_QT=ON ..
   注：在cmake时会去下载dnn模块的人脸模型，10M多点，不过下载速度比较慢，如果你之前下载过，可直接将模型 res10_300x300_ssd_iter_140000.caffemodel复制到文件夹**xx/opencv-3.4.0/samples/dnn/face_detector/**中。
6. make -j6//(run 6 jobs in parallel,但最好不要超过cpu核数，不然可能会出现错误)
   注：本人在make时会遇到C++内部错误，不用管它，再次make可继续编译，具体原因不知
7. sudo make install
8. 在执行imshow函数时，出现如下error
   OpenCV Error: Unspecified error (The function is not implemented. Rebuild the library with Windows, GTK+ 2.x or Carbon support. If you are on Ubuntu or Debian, install libgtk2.0-dev and pkg-config, then re-run cmake or configure script) in cvShowImage, file /home/nvidia/Documents/opencv-3.4.0/modules/highgui/src/window.cpp, line 611 terminate called after throwing an instance of cv::Exception
   解决方法：在cmake时加入-D WITH_QT=ON 选项
9. 在-D WITH_QT=ON 编译时，出现如下error
   error: #error Please include the appropriate gl headers before including cuda_gl_interop.h
   解决办法：修改文件/usr/local/cuda-8.0/targets/aarch64-linux/include/cuda_gl_interop.h如下，注释掉第8-12及第14行即可

7.#else /* __APPLE__ */
8.//#if defined(__arm__) || defined(__aarch64__)
9.//#ifndef GL_VERSION
10.//#error Please include the appropriate gl headers before including cuda_gl_interop.h
11.//#endif
12.//#else
13.#include <GL/gl.h>
14.//#endif
15.#endif /* __APPLE__ */

10. 读取视频时，出现error
    Unable to stop the stream: Inappropriate ioctl for device
    解决方法：安装ffmpeg
    sudo apt-get install ffmpeg
sudo apt-get install libavcodec-dev libavformat-dev libavdevice-dev 注：必须要装才行
    在cmake时能看到如下显示，则说明cmake使用ffmpeg编译成功
    
11. error：calling a constexpr __host__ function("abs") from a __device__ function("abs") is not allowed. The experimental flag '--expt-relaxed-constexpr' can be used to allow this.
    解方法：添加编译选项-D CUDA_NVCC_FLAGS=--expt-relaxed-constexpr
12. error：libopencv_imgcodecs.so.3.4.5: undefined reference to TIFFReadRGBAStrip@LIBTIFF_4.0
    解决方法：sudo apt install libtiff-dev
13. undefined reference to cv::softdouble::operator
    解决办法：这是由于链接库顺序的问题，将libopencv_core.so放到最后
14. undefined reference to __itt_metadata_add_ptr__3_0
    解决方法：链接上3rdparty/lib/libittnotify库
15. undefined reference to cvRemap
undefined reference to cvInitUndistortRectifyMap
undefined reference to cvConvertMaps
    解决办法：在cmake 时添加-DWITH_1394=OFF编译选项