“opencv2: no such file or directory” while trying to build Darknet?

问题

I am trying to use Darkent with OpenCV and CUDA. I installed darknet according to these instructions:

https://pjreddie.com/darknet/install/

I installed CUDA according to these instructions:

https://docs.nvidia.com/cuda/cuda-installation-guide-linux/index.html

Finally, I installed OpenCV according to these instructions:

http://www.linuxfromscratch.org/blfs/view/svn/general/opencv.html

I then added the following lines to the end of my bashrc:

export PATH=/usr/local/cuda-11.1/bin${PATH:+:${PATH}}
export LD_LIBRARY_PATH=/usr/local/cuda-11.1/lib64${LD_LIBRARY_PATH:+:${LD_LIBRARY_PATH}}
export PKG_CONFIG_PATH=/usr/local/lib/pkgconfig${PKG_CONFIG_PATH:+:${PKG_CONFIG_PATH}}

Next, I modified the Makefile in the darknet directory such that GPU=1, and OPENCV=1. I remade, and ran into a bunch of repeated errors saying:

No package 'opencv' found
gcc -Iinclude/ -Isrc/ -DOPENCV `pkg-config --cflags opencv`  -DGPU -I/usr/local/cuda/include/ -Wall -Wno-unused-result -Wno-unknown-pragmas -Wfatal-errors -fPIC -Ofast -DOPENCV -DGPU -c ./src/lstm_layer.c -o obj/lstm_layer.o
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

I checked, and although I had added the directory "/usr/local/lib/pkgconfig" to my PKG_CONFIG_PATH, there was no opencv.pc file there. I googled this, and read an answer that suggested to create the file manually, so this is what I did, with the following content:

prefix=/usr
exec_prefix=${prefix}
includedir=${prefix}/include
libdir=${exec_prefix}/lib

Name: opencv
Description: The opencv library
Version: 2.x.x
Cflags: -I${includedir}/opencv -I${includedir}/opencv2
Libs: -L${libdir} -lopencv_calib3d -lopencv_imgproc -lopencv_contrib -lopencv_legacy -l

This solved the repeating error mentioned above, but I am still getting a similar error when I make:

./src/image_opencv.cpp:5:10: fatal error: opencv2/opencv.hpp: No such file or directory
    5 | #include "opencv2/opencv.hpp"
      |          ^~~~~~~~~~~~~~~~~~~~
compilation terminated.

I'm not sure if I fixed the first issue, and this is a separate one, or if the first fix just fixed a symptom, and not the problem. Since then, I also tried:

sudo apt install libopencv-dev

to no effect.

pkg-config --modversion

produces: 2.x.x

pkg-config --cflags opencv

produces:

[code]
-I/usr/include/opencv -I/usr/include/opencv2
[/code]

Any help would be greatly appreciated. I am running ubuntu 20.04, kernel 5.4.0-53-generic.

回答1:

I tried this and it worked, create opencv.pc file with these contents:

# Package Information for pkg-config

prefix=/usr
exec_prefix=${prefix}
libdir=${prefix}/lib/x86_64-linux-gnu
includedir_new=${prefix}/include/opencv4

Name: OpenCV
Description: Open Source Computer Vision Library
Version: 4.5.0
Libs: -L${libdir} -lopencv_dnn -lopencv_ml -lopencv_objdetect -lopencv_shape -lopencv_stitching -lopencv_superres -lopencv_videostab -lopencv_calib3d -lopencv_features2d -lopencv_highgui -lopencv_videoio -lopencv_imgcodecs -lopencv_video -lopencv_photo -lopencv_imgproc -lopencv_flann -lopencv_core
Libs.private: -ldl -lm -lpthread -lrt
Cflags: -I${includedir_new}

and place it in /usr/local/lib/pkgconfig/.

来源：https://stackoverflow.com/questions/64865462/opencv2-no-such-file-or-directory-while-trying-to-build-darknet

标签

OpenCV

pkg-config

darknet