OpenCV 2.3 Compiling Issue - Undefined Refence - Ubuntu 11.10
50,988
Solution 1
I am guessing that at least some of the libraries in the output of
pkg-config opencv --libs
are archive libraries. It is incorrect to put archive libraries before sources that need them (test_1.cpp
in this case): the order of sources and libraries on the link line matters.
Try
g++ -o test_1 test_1.cpp `pkg-config opencv --cflags --libs`
Solution 2
I was having the same problem, but I found out pkg-config opencv --cflags is printing "-I/usr/include/opencv" instead of "-I/usr/include/opencv2"... Maybe a package bug on Ubuntu?
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Author by
Admin
Updated on May 07, 2020Comments
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Admin about 4 years
System Info: Ubuntu 11.10 (64 bits) with OpenCV 2.3 (installed today)
I'm trying to compile some very simple code in OpenCV 2.3 but I'm getting a weird error.
#include <opencv2/core/core.hpp> #include <opencv2/highgui/highgui.hpp> int main(){ cv::Mat image=cv::imread("img.jpg"); cv::namedWindow("My Image"); cv::imshow("My Image",image); cv::waitKey(0); return 1; }
however, I'm getting these error messages...
-SG41:~/Desktop$ g++ `pkg-config opencv --cflags --libs` -o test_1 test_1.cpp /tmp/ccCvS1ys.o: In function `main': test_1.cpp:(.text+0x44): undefined reference to `cv::imread(std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, int)' test_1.cpp:(.text+0x8e): undefined reference to `cv::namedWindow(std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, int)' test_1.cpp:(.text+0xbc): undefined reference to `cv::_InputArray::_InputArray(cv::Mat const&)' test_1.cpp:(.text+0xf0): undefined reference to `cv::imshow(std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, cv::_InputArray const&)' test_1.cpp:(.text+0x112): undefined reference to `cv::waitKey(int)' /tmp/ccCvS1ys.o: In function `cv::Mat::~Mat()': test_1.cpp:(.text._ZN2cv3MatD2Ev[_ZN2cv3MatD5Ev]+0x39): undefined reference to `cv::fastFree(void*)' /tmp/ccCvS1ys.o: In function `cv::Mat::release()': test_1.cpp:(.text._ZN2cv3Mat7releaseEv[cv::Mat::release()]+0x47): undefined reference to `cv::Mat::deallocate()' collect2: ld returned 1 exit status
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mecabpazzo95 over 12 yearsThanks! I just stared at this for an hour, and this was the answer.
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Trass3r over 12 yearsThx so much, I had the very same issue, even same OS and version.
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Gucci Koo almost 7 yearsstill having the same problem
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Sam Radhakrishnan almost 6 yearsI had the same issue on Ubuntu 16.04 and opencv 3 .4 and this solved the problem for me