No package 'opencv' found

[ANU197]

(tutorial-env) apdebian@ap:~/Music/darknet$ make
chmod +x *.sh
g++ -std=c++11 -std=c++11 -Iinclude/ -I3rdparty/stb/include -DOPENCV pkg-config --cflags opencv4 2> /dev/null || pkg-config --cflags opencv -Wall -Wfatal-errors -Wno-unused-result -Wno-unknown-pragmas -fPIC -Ofast -DOPENCV -c ./src/image_opencv.cpp -o obj/image_opencv.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
No package 'opencv' found
./src/image_opencv.cpp:16:10: fatal error: opencv2/core/version.hpp: No such file or directory
16 | #include <opencv2/core/version.hpp>
| ^~~~~~~~~~~~~~~~~~~~~~~~~~
compilation terminated.
make: *** [Makefile:174: obj/image_opencv.o] Error 1

i aleady download opencv from github

[AnhPC03]

Had you changed the 2nd line of the Makefile to: OPENCV=1?

[ANU197]

Yes, i changed in Makefile

[xwr96]

I also meet the same problem with you！do you solve？

[AnhPC03]

@ANU197 @xwr96 what was your opencv version?
Had you try sudo apt install libopencv-dev?

[xwr96]

@ANU197 @xwr96 what was your opencv version?
Had you try sudo apt install libopencv-dev?

my opencv version is 4.1.2. because I already install the opencv4, so I do not try 'sudo apt install libopencv-dev, do I try?

[AnhPC03]

@xwr96 Yes, You should try. Then let me know the result.

[xwr96]

@AnhPC03 I did, it response "libopencv-dev is already the newest version (3.2.0+dfsg-4ubuntu0.1).
0 to upgrade, 0 to newly install, 0 to remove and 135 not to upgrade." and it also doesn't work. the error message is :
No package 'opencv' found
./src/image_opencv.cpp:5:30: fatal error: opencv2/opencv.hpp: No such file or directory
compilation terminated.
Makefile:86: recipe for target 'obj/image_opencv.o' failed
make: *** [obj/image_opencv.o] Error 1

[AnhPC03]

Had you changed the two lines of the Makefile to: OPENCV=1 and GPU=1?
Then run make command?
After you change anything, just run make

[xwr96]

@AnhPC03 Yes. I already changed, but it error. In fact, it can run properly. but I think it use CPU,not a GPU, because it cost 21seconds

[AnhPC03]

if it can run properly but on CPU, change in Makefile to GPU=1 and run make again. I had ran it on GPU.
But opencv was still error?

[xwr96]

if it can run properly but on CPU, change in Makefile to GPU=1 and run make again. I had ran it on GPU.

when I change the 'GPU'=1, opencv=1, it cause error above what I said. So I confused

[AnhPC03]

What will be output when you run pkg-config --cflags opencv?

[xwr96]

@AnhPC03 the output is
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
No package 'opencv' found
`

[AnhPC03]

@xwr96 check your opencv package, if exist, uninstall it. Then run pip install opencv-python.
Let me know the result after you run pkg-config --cflags opencv again

[ck196]

@xwr96 When you install OpenCV manually, you should install with release.

cmake --build . --config Release

And libopencv will be installed to /usr/lib

So, confirm it by:

pkg-config --modversion opencv

[xwr96]

@ck196 it turns out
Error: could not load cache

[xwr96]

@xwr96 check your opencv package, if exist, uninstall it. Then run pip install opencv-python.
Let me know the result after you run pkg-config --cflags opencv again

ok, I have a try. Thanks!

[essanhaji]

Hi dear,
i have same problem and i save it with installing libopencv-dev and remake again,
if you are using a CPU like me make sur to set GPU to 0 and make opencv to 1 in makefile,

GPU=0
OPENCV=1

sudo apt-get install libopencv-dev
make

i hop you solve it

[ABHIINAV12]

I have same problem, tried everything above. What to set in path by the way ?

[cgironda]

Thanks to the comments of @AnhPC03 and @essanhaji, I solved my problem on a Droplet created in "Digitalocean".
Before using the make command, I made the installation below to avoid problems during the compilation process.

sudo apt-get install g++

I hope this would help to anyone.

[vivek9patel]

I just had the same problem,
it can be solved just by installing OpenCV using,

sudo apt install libopencv-dev

[Batuhanakd]

I just had the same problem,
it can be solved just by installing OpenCV using,

sudo apt install libopencv-dev

That applies to me too. I just run sudo apt install libopencv-dev

[himanshuknegi]

@xwr96 Yes, You should try. Then let me know the result.

it is working

[zarraozaga]

sudo apt install libopencv-dev will install opencv in pkg-config --cflags opencv4 but not in pkg-config --cflags opencv. Anyone
knows how to fix this?

[ganesh15220]

I just had the same problem,
it can be solved just by installing OpenCV using,
sudo apt install libopencv-dev

That applies to me too. I just run sudo apt install libopencv-dev

This is working for me

[janbertoo]

Hi all, on my local machine (ubuntu) I had the same error (even though I already had opencv installed using pip) which was solved with installing libopencv-dev using apt install.

However, now I am trying to run the code on another machine (also ubuntu) in which I only have a virtual environment. When I install libopencv-dev using apt install I will install it system-wide, which might mess up other users of the machine.

So now I tried "conda install -c anaconda libopencv" as conda is supposed to install it only on my virtual environment. However, after succesfull installation (now both with pip and conda) it still gives me the same error: "No package 'opencv' found" when I am trying to 'make' darknet.

Can someody help?

[robsss]

@zarraozaga maybe we could shift to another repo, like AlexeyAB's repo.

[raisinbl]

I just found out that the OpenCV package that installed from sudo apt install libopencv-dev is opencv4 which is located in \usr\include. And under that opencv4 folder, guess what we have? Yes, the opencv2 folder.

So to overcome this problem when you change the OPENCV= 1 on Makefile and show up **fatal error** opencv2/core/version.hpp: No such file or directory

All the thing you need to do is just change on the line 45, 46

45 LDFLAGS+= `pkg-config --libs opencv` -lstdc++
46 COMMON+= `pkg-config --cflags opencv` 

to

LDFLAGS+= `pkg-config --libs opencv4` -lstdc++
COMMON+= `pkg-config --cflags opencv4` 

Conclusion: Just install OpenCV by sudo apt-get install libopencv-dev, change opencv on line 45, 46 on Makefile to opencv4.

[happyamyhope]

I just found out that the OpenCV package that installed from sudo apt install libopencv-dev is opencv4 which is located in \usr\include. And under that opencv4 folder, guess what we have? Yes, the opencv2 folder.

So to overcome this problem when you change the OPENCV= 1 on Makefile and show up **fatal error** opencv2/core/version.hpp: No such file or directory

All the thing you need to do is just change on the line 45, 46

45 LDFLAGS+= `pkg-config --libs opencv` -lstdc++
46 COMMON+= `pkg-config --cflags opencv` 

to

LDFLAGS+= `pkg-config --libs opencv4` -lstdc++
COMMON+= `pkg-config --cflags opencv4` 

Conclusion: Just install OpenCV by sudo apt-get install libopencv-dev, change opencv on line 45, 46 on Makefile to opencv4.

this does not work for me.

[Thakay]

I just found out that the OpenCV package that installed from sudo apt install libopencv-dev is opencv4 which is located in \usr\include. And under that opencv4 folder, guess what we have? Yes, the opencv2 folder.

So to overcome this problem when you change the OPENCV= 1 on Makefile and show up **fatal error** opencv2/core/version.hpp: No such file or directory

All the thing you need to do is just change on the line 45, 46

45 LDFLAGS+= `pkg-config --libs opencv` -lstdc++
46 COMMON+= `pkg-config --cflags opencv` 

to

LDFLAGS+= `pkg-config --libs opencv4` -lstdc++
COMMON+= `pkg-config --cflags opencv4` 

Conclusion: Just install OpenCV by sudo apt-get install libopencv-dev, change opencv on line 45, 46 on Makefile to opencv4.

Works but needs C++11 !!!

[edgarcorrea1]

Hi dear, i have same problem and i save it with installing libopencv-dev and remake again, if you are using a CPU like me make sur to set GPU to 0 and make opencv to 1 in makefile,

GPU=0
OPENCV=1

sudo apt-get install libopencv-dev
make

i hop you solve it

Hi, I have the same problem but in mac, you know how to solve it, it mac is not posible to use apt-get, but the issue is the same

[AlanTuring42]

Hi, I have the same problem but in mac, you know how to solve it, it mac is not posible to use apt-get, but the issue is the same

Check here #2505 (comment)