Question

更新：代码在另一台计算机上成功编译。所以问题不在于代码本身，而在于我安装了依赖项的方式。

如果我遗漏了任何必要的信息，请告诉我。完整代码可以找到here。

以下代码使用these instructions从SourceForge新安装的OpenCV 3.2.0在Ubuntu 14.04上编译并运行完全正常：

#include <stdio.h>
#include <opencv2/opencv.hpp>

using namespace cv;

int main(int argc, char** argv )
{
    Mat image;
    image = imread( argv[1], 1 );
    namedWindow("Display Image", WINDOW_AUTOSIZE );
    imshow("Display Image", image);
    waitkey(0);

    return 0;
}

使用以下CMakeLists.txt：

 cmake_minimum_required(VERSION 2.8)
 project( DisplayImage )
 find_package( OpenCV REQUIRED )
 add_executable( DisplayImage DisplayImage.cpp )
 target_link_libraries( DisplayImage ${OpenCV_LIBS} )

以下代码无法编译。

lane_finder.h

#ifndef Lane_Finder_h
#define Lane_Finder_h

#include <stdio.h>
#include <ros/ros.h>
#include <sensor_msgs/Image.h>
#include <sensor_msgs/image_encodings.h>
#include <cv_bridge/cv_bridge.h>
#include <opencv2/opencv.hpp>

class LaneFinder
{ *snip* }

#endif

lane_finder.cpp：

#include "lane_finder.h"

sensor_msgs::CompressedImage LaneFinder::findLanes(const sensor_msgs::Image& msg) {
    *snip*
    frame = in_msg->image;

    cv::namedWindow("Display Image", cv::WINDOW_AUTOSIZE );
    cv::imshow("Display Image", frame);
    *snip*
}

的CMakeLists.txt：

cmake_minimum_required(VERSION 2.8.3)
project(lane_finding)
find_package(catkin REQUIRED COMPONENTS roscpp cv_bridge sensor_msgs)
find_package(OpenCV REQUIRED)
catkin_package()
include_directories(include ${catkin_INCLUDE_DIRS} ${OpenCV_INCLUDE_DIRS})
add_executable(lane_finder src/lane_finder.cpp src/main.cpp)
target_link_libraries(lane_finder
   ${catkin_LIBRARIES}
   ${OpenCV_LIBS}
)

编译错误：

CMakeFiles/lane_finder.dir/src/lane_finder.cpp.o: In function `LaneFinder::findLanes(sensor_msgs::Image_<std::allocator<void> > const&)':
lane_finder.cpp:(.text+0x36c): undefined reference to `cv::namedWindow(cv::String const&, int)'
lane_finder.cpp:(.text+0x3c1): undefined reference to `cv::imshow(cv::String const&, cv::_InputArray const&)'
CMakeFiles/lane_finder.dir/src/lane_finder.cpp.o: In function `cv::String::String(char const*)':
lane_finder.cpp:(.text._ZN2cv6StringC2EPKc[_ZN2cv6StringC5EPKc]+0x4f): undefined reference to `cv::String::allocate(unsigned long)'
CMakeFiles/lane_finder.dir/src/lane_finder.cpp.o: In function `cv::String::~String()':
lane_finder.cpp:(.text._ZN2cv6StringD2Ev[_ZN2cv6StringD5Ev]+0x14): undefined reference to `cv::String::deallocate()'
CMakeFiles/lane_finder.dir/src/lane_finder.cpp.o: In function `cv::String::operator=(cv::String const&)':
lane_finder.cpp:(.text._ZN2cv6StringaSERKS0_[_ZN2cv6StringaSERKS0_]+0x28): undefined reference to `cv::String::deallocate()'
collect2: error: ld returned 1 exit status

我不能为我的生活弄清楚为什么一个人跑得很好而另一个人失败了。我怀疑我已经链接了一些不正确的东西，因为这是我第一次尝试使用我自己编写的头文件进行编译。如果你认为我在试图保持这种可读性方面省略了一些重要内容，那么我已经在本文开头包含了一个包含完整代码的github repo的链接。

非常感谢你们。

Answer 1

You should add this option:

pkg-config opencv --cflags --libs

Answer 2

我的平台：

Win10 64位
QT58（mingw53）

安装opencv 3.30后，我编写代码：

//main.cc
#include <iostream>
#include <QDir>
#include <qdebug>
#include "opencv2/opencv.hpp"
using namespace std;
int main()
{
    qDebug()<< QDir::currentPath();
    cv::Mat image = cv::imread("1.jpg",1);
    std::cout << image.cols << " " << image.rows << std::endl;
    if(image.data == 0){
        cout << "No Image" <<endl;
    }
    else{
        cout << "Image" << endl;
    }
   cv::namedWindow("My Image");
   cv::imshow("My Image", image)    

   system("pause");
   return 0;
 }

我得到这样的错误：

release/main.o:main.cpp:(.text.startup+0x170): undefined reference to `cv::imshow(cv::String const&, cv::_InputArray const&)'
collect2.exe: error: ld returned 1 exit status

我不知道为什么，但是其他函数运行良好，请期待imshow（）。我确实添加了LIBS：

//qt.pro
INCLUDEPATH += D:\opencv\build\mingw\include    

LIBS += D:\opencv\build\mingw\x86\mingw\bin\libopencv_highgui330.dll
LIBS += D:\opencv\build\mingw\x86\mingw\bin\libopencv_calib3d330.dll
LIBS += D:\opencv\build\mingw\x86\mingw\bin\libopencv_dnn330.dll
LIBS += D:\opencv\build\mingw\x86\mingw\bin\libopencv_features2d330.dll
LIBS += D:\opencv\build\mingw\x86\mingw\bin\libopencv_flann330.dll
LIBS += D:\opencv\build\mingw\x86\mingw\bin\libopencv_imgcodecs330.dll
LIBS += D:\opencv\build\mingw\x86\mingw\bin\libopencv_imgproc330.dll
LIBS += D:\opencv\build\mingw\x86\mingw\bin\libopencv_ml330.dll
LIBS += D:\opencv\build\mingw\x86\mingw\bin\libopencv_objdetect330.dll
LIBS += D:\opencv\build\mingw\x86\mingw\bin\libopencv_photo330.dll
LIBS += D:\opencv\build\mingw\x86\mingw\bin\libopencv_shape330.dll
LIBS += D:\opencv\build\mingw\x86\mingw\bin\libopencv_stitching330.dll
LIBS += D:\opencv\build\mingw\x86\mingw\bin\libopencv_superres330.dll
LIBS += D:\opencv\build\mingw\x86\mingw\bin\libopencv_video330.dll
LIBS += D:\opencv\build\mingw\x86\mingw\bin\libopencv_videoio330.dll
LIBS += D:\opencv\build\mingw\x86\mingw\bin\libopencv_videostab330.dll
LIBS += D:\opencv\build\mingw\x86\mingw\bin\opencv_ffmpeg330.dll
LIBS += D:\opencv\build\mingw\x86\mingw\bin\libopencv_core330.dll

Answer 3

cv_bridge依赖于OpenCV 2.4。更改CMakeLists.txt以指定：

find_package(OpenCV 2 REQUIRED)

OpenCV：对`cv :: namedWindow（cv :: String const＆amp;，int）＆＃39;的未定义引用

3 个答案: