C++ 由于未定义的引用，无法编译 OpenCV？
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/24337932/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
Cannot get OpenCV to compile because of undefined references?
提问by sherrellbc
The code is simple and is essentially straight from thistutorial. I am running Arch Linux and have the OpenCV library stored at /usr/include/. I have also checked to ensure that /usr/includeis in my PATH.
代码很简单，基本上直接来自本教程。我正在运行 Arch Linux 并将 OpenCV 库存储在/usr/include/. 我还检查过以确保它/usr/include在我的 PATH 中。
#include <opencv/cv.h>
#include <opencv/highgui.h>
#include <iostream>
using namespace cv;
int main(int argc, char** argv){
Mat image;
Mat grayImage;
if(!argv[1]){
std::cerr << "No image data!" << std::endl;
return -1;
}
image = imread(argv[1], 1);
cvtColor(image, grayImage, CV_BGR2GRAY);
imwrite("Gray_Image.jpg", grayImage);
namedWindow(argv[1], CV_WINDOW_AUTOSIZE);
namedWindow("Gray Image", CV_WINDOW_AUTOSIZE);
imshow(argv[1], image);
imshow("Gray Image", grayImage);
waitKey(0);
return 0;
}
The compiler process successfully finds and include these header files, but I still get undefined reference errors at compile-time. If you look into the header files I included they further include other files in /usr/include/opencv2. I have checked and such header files do exist.
编译器进程成功找到并包含这些头文件，但在编译时我仍然收到未定义的引用错误。如果您查看我包含的头文件，它们会进一步包含/usr/include/opencv2. 我已经检查过，确实存在这样的头文件。
Any ideas?
有任何想法吗？
/tmp/ccudBcqD.o: In function `main':
test.cpp:(.text+0xc0): undefined reference to `cv::imread(std::string const&, int)'
test.cpp:(.text+0x11f): undefined reference to `cv::_OutputArray::_OutputArray(cv::Mat&)'
test.cpp:(.text+0x138): undefined reference to `cv::_InputArray::_InputArray(cv::Mat const&)'
test.cpp:(.text+0x158): undefined reference to `cv::cvtColor(cv::_InputArray const&, cv::_OutputArray const&, int, int)'
test.cpp:(.text+0x180): undefined reference to `cv::_InputArray::_InputArray(cv::Mat const&)'
test.cpp:(.text+0x1ca): undefined reference to `cv::imwrite(std::string const&, cv::_InputArray const&, std::vector<int, std::allocator<int> > const&)'
test.cpp:(.text+0x241): undefined reference to `cv::namedWindow(std::string const&, int)'
test.cpp:(.text+0x291): undefined reference to `cv::namedWindow(std::string const&, int)'
test.cpp:(.text+0x2bf): undefined reference to `cv::_InputArray::_InputArray(cv::Mat const&)'
test.cpp:(.text+0x2ff): undefined reference to `cv::imshow(std::string const&, cv::_InputArray const&)'
test.cpp:(.text+0x32d): undefined reference to `cv::_InputArray::_InputArray(cv::Mat const&)'
test.cpp:(.text+0x361): undefined reference to `cv::imshow(std::string const&, cv::_InputArray const&)'
test.cpp:(.text+0x383): undefined reference to `cv::waitKey(int)'
/tmp/ccudBcqD.o: In function `cv::Mat::~Mat()':
test.cpp:(.text._ZN2cv3MatD2Ev[_ZN2cv3MatD5Ev]+0x39): undefined reference to `cv::fastFree(void*)'
/tmp/ccudBcqD.o: In function `cv::Mat::operator=(cv::Mat const&)':
test.cpp:(.text._ZN2cv3MataSERKS0_[_ZN2cv3MataSERKS0_]+0x111): undefined reference to `cv::Mat::copySize(cv::Mat const&)'
/tmp/ccudBcqD.o: In function `cv::Mat::release()':
test.cpp:(.text._ZN2cv3Mat7releaseEv[_ZN2cv3Mat7releaseEv]+0x47): undefined reference to `cv::Mat::deallocate()'
collect2: error: ld returned 1 exit status
[Finished in 1.1s with exit code 1]
[shell_cmd: g++ "/home/branden/Desktop/OpenCV/test.cpp" -o "/home/branden/Desktop/OpenCV/test"]
[dir: /home/branden/Desktop/OpenCV]
[path: /usr/local/sbin:/usr/local/bin:/usr/bin:/usr/bin/vendor_perl:/usr/bin/core_perl]
回答by Plamen Tetevensky
This is a linker issue. Try:
这是链接器问题。尝试：
g++ -o test_1 test_1.cpp `pkg-config opencv --cflags --libs`
This should work to compile the source. However, if you recently compiled OpenCV from source, you will meet linking issue in run-time, the library will not be found. In most cases, after compiling libraries from source, you need to do finally:
这应该可以编译源代码。但是，如果您最近从源代码编译 OpenCV，您将在运行时遇到链接问题，将找不到该库。在大多数情况下，从源代码编译库后，您需要做最后的事情：
sudo ldconfig
回答by Merlin
I have tried all solution. The -lopencv_core -lopencv_imgproc -lopencv_highguiin comments solved my problem. And know my command line looks like this in geany:
我已经尝试了所有解决方案。在-lopencv_core -lopencv_imgproc -lopencv_highgui注释中解决我的问题。并且知道我的命令行在 geany 中是这样的：
g++ -lopencv_core -lopencv_imgproc -lopencv_highgui -o "%e" "%f"
When I build:
当我构建时：
g++ -lopencv_core -lopencv_imgproc -lopencv_highgui -o "opencv" "opencv.cpp" (in directory: /home/fedora/Desktop/Implementations)
The headers are:
标题是：
#include "opencv2/imgproc/imgproc.hpp"
#include "opencv2/highgui/highgui.hpp"
回答by Ar maj
follow this tutorial. i ran the install-opencv.shfile in bash. its in the tutorial
按照本教程。我在 bash 中运行了install-opencv.sh文件。它在教程中
read the example from openCV
从 openCV 中读取示例
CMakeLists.txt
CMakeLists.txt
cmake_minimum_required(VERSION 3.7)
project(openCVTest)
# cmake needs this line
cmake_minimum_required(VERSION 2.8)
# Define project name
project(opencv_example_project)
# Find OpenCV, you may need to set OpenCV_DIR variable
# to the absolute path to the directory containing OpenCVConfig.cmake file
# via the command line or GUI
find_package(OpenCV REQUIRED)
# If the package has been found, several variables will
# be set, you can find the full list with descriptions
# in the OpenCVConfig.cmake file.
# Print some message showing some of them
message(STATUS "OpenCV library status:")
message(STATUS " version: ${OpenCV_VERSION}")
message(STATUS " libraries: ${OpenCV_LIBS}")
message(STATUS " include path: ${OpenCV_INCLUDE_DIRS}")
if(CMAKE_VERSION VERSION_LESS "2.8.11")
# Add OpenCV headers location to your include paths
include_directories(${OpenCV_INCLUDE_DIRS})
endif()
# Declare the executable target built from your sources
add_executable(main main.cpp)
# Link your application with OpenCV libraries
target_link_libraries(main ${OpenCV_LIBS})
main.cpp
主程序
/**
* @file LinearBlend.cpp
* @brief Simple linear blender ( dst = alpha*src1 + beta*src2 )
* @author OpenCV team
*/
#include "opencv2/imgcodecs.hpp"
#include "opencv2/highgui.hpp"
#include <stdio.h>
using namespace cv;
/** Global Variables */
const int alpha_slider_max = 100;
int alpha_slider;
double alpha;
double beta;
/** Matrices to store images */
Mat src1;
Mat src2;
Mat dst;
//![on_trackbar]
/**
* @function on_trackbar
* @brief Callback for trackbar
*/
static void on_trackbar( int, void* )
{
alpha = (double) alpha_slider/alpha_slider_max ;
beta = ( 1.0 - alpha );
addWeighted( src1, alpha, src2, beta, 0.0, dst);
imshow( "Linear Blend", dst );
}
//![on_trackbar]
/**
* @function main
* @brief Main function
*/
int main( void )
{
//![load]
/// Read images ( both have to be of the same size and type )
src1 = imread("../data/LinuxLogo.jpg");
src2 = imread("../data/WindowsLogo.jpg");
//![load]
if( src1.empty() ) { printf("Error loading src1 \n"); return -1; }
if( src2.empty() ) { printf("Error loading src2 \n"); return -1; }
/// Initialize values
alpha_slider = 0;
//![window]
namedWindow("Linear Blend", WINDOW_AUTOSIZE); // Create Window
//![window]
//![create_trackbar]
char TrackbarName[50];
sprintf( TrackbarName, "Alpha x %d", alpha_slider_max );
createTrackbar( TrackbarName, "Linear Blend", &alpha_slider, alpha_slider_max, on_trackbar );
//![create_trackbar]
/// Show some stuff
on_trackbar( alpha_slider, 0 );
/// Wait until user press some key
waitKey(0);
return 0;
}
Tested in linux mint 17
在 linux mint 17 中测试
回答by Hasan Zakaria Alhajhamad
if anyone still having this problem. One solution is to rebuild the source OpenCV library using MinGW and not use the binaries given by OpenCV. I did it and it worked like a charm.
如果有人仍然遇到这个问题。一种解决方案是使用 MinGW 重建源 OpenCV 库，而不使用 OpenCV 提供的二进制文件。我做到了，它就像一个魅力。
回答by SuperEye
If you do the following, you will be able to use opencv build from OpenCV_INSTALL_PATH.
如果您执行以下操作，您将能够使用 OpenCV_INSTALL_PATH 中的 opencv 构建。
cmake_minimum_required(VERSION 2.8)
SET(OpenCV_INSTALL_PATH /home/user/opencv/opencv-2.4.13/release/)
SET(OpenCV_INCLUDE_DIRS "${OpenCV_INSTALL_PATH}/include/opencv;${OpenCV_INSTALL_PATH}/include")
SET(OpenCV_LIB_DIR "${OpenCV_INSTALL_PATH}/lib")
LINK_DIRECTORIES(${OpenCV_LIB_DIR})
set(OpenCV_LIBS opencv_core opencv_imgproc opencv_calib3d opencv_video opencv_features2d opencv_ml opencv_highgui opencv_objdetect opencv_contrib opencv_legacy opencv_gpu)
# find_package( OpenCV )
project(edge.cpp)
add_executable(edge edge.cpp)
回答by rogerdpack
For me, this type of error:
对我来说，这种类型的错误：
mingw-w64-x86_64/lib/gcc/x86_64-w64-mingw32/8.2.0/../../../../x86_64-w64-mingw32/bin/ld: mingw-w64-x86_64/x86_64-w64-mingw32/lib/libTransform360.a(VideoFrameTransform.cpp.obj):VideoFrameTransform.cpp:(.text+0xc7c):
undefined reference to `cv::Mat::Mat(cv::Mat const&, cv::Rect_<int> const&)'
meant load order, I had to do -lTransform360 -lopencv_dnn345 -lopencv...just like that, that order.
And putting them right next to each other helped too, don't put -lTransform360all the way at the beginning...or you'll get, for some freaky reason:
意味着加载顺序，我必须这样做-lTransform360 -lopencv_dnn345 -lopencv...，那个顺序。将它们并排放置也有帮助，不要-lTransform360一开始就完全放置……否则你会得到，出于某种奇怪的原因：
undefined reference to `VideoFrameTransform_new'
undefined reference to `VideoFrameTransform_generateMapForPlane'
...
...
