OpenCV 未定义对 Mat 的引用

Question

我正在尝试在 C++ 中学习 openCV，并且正在使用 Windows 7(x64) 上最新版本的 openCV 处理代码块 13.12。一开始我测试了我的网络摄像头的一个简单输出，女巫工作没有问题。接下来，我尝试使用cvtColor(img, img_gray, CV_BGR2GRAY) 修改输出。正如您在下面看到的，我收到 2 条错误消息。另外澄清一下，VisuWork vW 是我为了在OOP 中正确编码作为练习而创建的一个类。班级没有做任何特别的事情。 请问谁能帮我找到这个问题的问题？ 感谢您的帮助和时间。

---

main.cpp：

#include <stdio.h>
#include <stdlib.h>
#include <iostream>
#include <opencv2/highgui/highgui.hpp>
#include <opencv2/imgproc/imgproc.hpp>
#include <opencv2/highgui/highgui_c.h>
#include <opencv/highgui.h>

using namespace cv;
using namespace std;

    class VisuWork
    {
        CvCapture* capture;
    public:
        VisuWork()
        {
            capture=cvCaptureFromCAM(CV_CAP_ANY);
        };
        template<typename Type> void sHow(Type frame)
        {
    //        IplImage* frame = cvQueryFrame(capture); //Create image frames from capture
            cvShowImage("Camera_Output", frame); //Show image frames on created window
        }
    //    void imHSV(IplImage* frame){
    //        Mat im(frame);
    //        Mat hsv;
    //        cvtColor(im, hsv, CV_BGR2HSV);
    //    }
        ~VisuWork()
        {
            cvReleaseCapture(&capture); //Release capture.
            cvDestroyWindow("Camera_Output"); //Destroy Window
        }

    };

        int main( int argc, const char** argv )
        {
            CvCapture* capture = 0;
            capture = cvCaptureFromCAM(CV_CAP_ANY);
            if (!capture)
            {
                // print error, quit application
            }
            else
            {
                VisuWork vW;
                while(1)  //Create infinte loop for live streaming
                {
                    IplImage* im = cvQueryFrame(capture);
                    if(!im){}
                    else{
                    //        vW.imHSV(frame);

                    Mat img_gray(im);
                    vW.sHow(im);
                  cvtColor(img, img_gray, CV_BGR2GRAY);
                    }
                    int key = cvWaitKey(10); //Capture Keyboard stroke
                    if (char(key) == 27)
                    {
                        break; //If you hit ESC key loop will break.
                    }
                }
                cvReleaseCapture(&capture); //Release capture.
                cvDestroyWindow("Camera_Output"); //Destroy Window
            }

        }

---

错误信息：

C:\Users\PTOSH\Documents\tried.o:tried.cpp:(.text+0x7b): undefined reference to cv::Mat::Mat(_IplImage const*, bool) C:\Users\PTOSH\Documents\tried.o:tried.cpp:(.text$_ZN2cv3MatD1Ev[__ZN2cv3MatD1Ev]+0x2d): undefined reference to cv::fastFree(void*)

---

这是完整的构建日志：

---

mingw32-g++.exe -std=c++11 -Wall -IC:\RPS\python\edp32\opencv\build\include -c C:\Users\PTOSH\Documents\tried.cpp -o C: \Users\PTOSH\Documents\tried.o mingw32-g++.exe -LC:\RPS\python\edp32\opencv\build\x86\vc12\lib -L"C:\Program Files (x86)\CodeBlocks\MinGW\lib" -LC:\RPS\python\ edp32\opencv\sources\3rdparty -o C:\Users\PTOSH\Documents\tried.exe C:\Users\PTOSH\Documents\tried.o C:\RPS\python\edp32\opencv\build\x86\vc12\ lib\opencv_calib3d248.lib C:\RPS\python\edp32\opencv\build\x86\vc12\lib\opencv_calib3d248d.lib C:\RPS\python\edp32\opencv\build\x86\vc12\lib\opencv_contrib248.lib C :\RPS\python\edp32\opencv\build\x86\vc12\lib\opencv_contrib248d.lib C:\RPS\python\edp32\opencv\build\x86\vc12\lib\opencv_core248.lib C:\RPS\python\ edp32\opencv\build\x86\vc12\lib\opencv_core248d.lib C:\RPS\python\edp32\opencv\build\x86\vc12\lib\opencv_features2d248.lib C:\RPS\python\edp32\opencv\build\ x86\vc12\lib\opencv_features2d248d.lib C:\RPS\python\edp32\opencv\build\x86\vc12\lib\opencv_flann248.lib C:\RPS\python\edp32\opencv\build\x86\vc12\lib\ opencv_flann248d.lib C:\RPS\python\edp32\opencv\build\x86\vc12\lib\opencv_gpu248.lib C:\RPS\python\edp32\open cv\build\x86\vc12\lib\opencv_gpu248d.lib C:\RPS\python\edp32\opencv\build\x86\vc12\lib\opencv_highgui248.lib C:\RPS\python\edp32\opencv\build\x86\ vc12\lib\opencv_highgui248d.lib C:\RPS\python\edp32\opencv\build\x86\vc12\lib\opencv_imgproc248.lib C:\RPS\python\edp32\opencv\build\x86\vc12\lib\opencv_imgproc248d。库 C:\RPS\python\edp32\opencv\build\x86\vc12\lib\opencv_legacy248.lib C:\RPS\python\edp32\opencv\build\x86\vc12\lib\opencv_legacy248d.lib C:\RPS\ python\edp32\opencv\build\x86\vc12\lib\opencv_ml248.lib C:\RPS\python\edp32\opencv\build\x86\vc12\lib\opencv_ml248d.lib C:\RPS\python\edp32\opencv\ build\x86\vc12\lib\opencv_nonfree248.lib C:\RPS\python\edp32\opencv\build\x86\vc12\lib\opencv_nonfree248d.lib C:\RPS\python\edp32\opencv\build\x86\vc12\ lib\opencv_objdetect248.lib C:\RPS\python\edp32\opencv\build\x86\vc12\lib\opencv_objdetect248d.lib C:\RPS\python\edp32\opencv\build\x86\vc12\lib\opencv_ocl248.lib C :\RPS\python\edp32\opencv\build\x86\vc12\lib\opencv_ocl248d.lib C:\RPS\python\ed p32\opencv\build\x86\vc12\lib\opencv_photo248.lib C:\RPS\python\edp32\opencv\build\x86\vc12\lib\opencv_photo248d.lib C:\RPS\python\edp32\opencv\build\ x86\vc12\lib\opencv_stitching248.lib C:\RPS\python\edp32\opencv\build\x86\vc12\lib\opencv_stitching248d.lib C:\RPS\python\edp32\opencv\build\x86\vc12\lib\ opencv_superres248.lib C:\RPS\python\edp32\opencv\build\x86\vc12\lib\opencv_superres248d.lib C:\RPS\python\edp32\opencv\build\x86\vc12\lib\opencv_ts248.lib C:\ RPS\python\edp32\opencv\build\x86\vc12\lib\opencv_ts248d.lib C:\RPS\python\edp32\opencv\build\x86\vc12\lib\opencv_video248.lib C:\RPS\python\edp32\ opencv\build\x86\vc12\lib\opencv_video248d.lib C:\RPS\python\edp32\opencv\build\x86\vc12\lib\opencv_videostab248.lib C:\RPS\python\edp32\opencv\build\x86\ vc12\lib\opencv_videostab248d.lib C:\RPS\python\edp32\opencv\build\x64\vc12\lib\opencv_calib3d248.lib C:\RPS\python\edp32\opencv\build\x64\vc12\lib\opencv_calib3d248d。库 C:\RPS\python\edp32\opencv\build\x64\vc12\lib\opencv_contrib248.l ib C:\RPS\python\edp32\opencv\build\x64\vc12\lib\opencv_contrib248d.lib C:\RPS\python\edp32\opencv\build\x64\vc12\lib\opencv_core248.lib C:\RPS\ python\edp32\opencv\build\x64\vc12\lib\opencv_core248d.lib C:\RPS\python\edp32\opencv\build\x64\vc12\lib\opencv_features2d248.lib C:\RPS\python\edp32\opencv\ build\x64\vc12\lib\opencv_features2d248d.lib C:\RPS\python\edp32\opencv\build\x64\vc12\lib\opencv_flann248.lib C:\RPS\python\edp32\opencv\build\x64\vc12\ lib\opencv_flann248d.lib C:\RPS\python\edp32\opencv\build\x64\vc12\lib\opencv_gpu248.lib C:\RPS\python\edp32\opencv\build\x64\vc12\lib\opencv_gpu248d.lib C :\RPS\python\edp32\opencv\build\x64\vc12\lib\opencv_highgui248.lib C:\RPS\python\edp32\opencv\build\x64\vc12\lib\opencv_highgui248d.lib C:\RPS\python\ edp32\opencv\build\x64\vc12\lib\opencv_imgproc248.lib C:\RPS\python\edp32\opencv\build\x64\vc12\lib\opencv_imgproc248d.lib C:\RPS\python\edp32\opencv\build\ x64\vc12\lib\opencv_legacy248.lib C:\RPS\python\edp32\opencv\build\x64\vc12\lib\openc v_legacy248d.lib C:\RPS\python\edp32\opencv\build\x64\vc12\lib\opencv_ml248.lib C:\RPS\python\edp32\opencv\build\x64\vc12\lib\opencv_ml248d.lib C:\ RPS\python\edp32\opencv\build\x64\vc12\lib\opencv_nonfree248.lib C:\RPS\python\edp32\opencv\build\x64\vc12\lib\opencv_nonfree248d.lib C:\RPS\python\edp32\ opencv\build\x64\vc12\lib\opencv_objdetect248.lib C:\RPS\python\edp32\opencv\build\x64\vc12\lib\opencv_objdetect248d.lib C:\RPS\python\edp32\opencv\build\x64\ vc12\lib\opencv_ocl248.lib C:\RPS\python\edp32\opencv\build\x64\vc12\lib\opencv_ocl248d.lib C:\RPS\python\edp32\opencv\build\x64\vc12\lib\opencv_photo248。库 C:\RPS\python\edp32\opencv\build\x64\vc12\lib\opencv_photo248d.lib C:\RPS\python\edp32\opencv\build\x64\vc12\lib\opencv_stitching248.lib C:\RPS\ python\edp32\opencv\build\x64\vc12\lib\opencv_stitching248d.lib C:\RPS\python\edp32\opencv\build\x64\vc12\lib\opencv_superres248.lib C:\RPS\python\edp32\opencv\构建\x64\vc12\lib\opencv_superres248d.lib C:\RPS\python\edp32\opencv\build\x64 \vc12\lib\opencv_ts248.lib C:\RPS\python\edp32\opencv\build\x64\vc12\lib\opencv_ts248d.lib C:\RPS\python\edp32\opencv\build\x64\vc12\lib\opencv_video248 .lib C:\RPS\python\edp32\opencv\build\x64\vc12\lib\opencv_video248d.lib C:\RPS\python\edp32\opencv\build\x64\vc12\lib\opencv_videostab248.lib C:\RPS \python\edp32\opencv\build\x64\vc12\lib\opencv_videostab248d.lib C:\Users\PTOSH\Documents\tried.o:tried.cpp:(.text+0x7b): 未定义引用cv::Mat::Mat(_IplImage const*, bool)' C:\Users\PTOSH\Documents\tried.o:tried.cpp:(.text$_ZN2cv3MatD1Ev[__ZN2cv3MatD1Ev]+0x2d): undefined reference tocv::fastFree(void)'* c:/程序文件 (x86)/codeblocks/mingw/bin/../lib/gcc/mingw32/4.8.1/../../../../mingw32/bin/ld.exe: C: \Users\PTOSH\Documents\tried.o：`.text$_ZN2cv3MatD1Ev[__ZN2cv3MatD1Ev]' 部分中的错误重定位地址 0x2d c:/program files (x86)/codeblocks/mingw/bin/../lib/gcc/mingw32/4.8.1/../../../../mingw32/bin/ld.exe：最终链接失败：无效操作 collect2.exe：错误：ld 返回 1 退出状态 进程以状态 1 终止（0 分钟，1 秒） 2 个错误，0 个警告（0 分钟，1 秒）

Answer 1

如果你真的想使用 c++ api（你应该使用，因为旧的 c-one 已死），

CvCapture* capture; 
// no, use: cv::VideoCapture

IplImage* frame = cvQueryFrame(capture); 
// no, use: cv::Mat frame; capture.read(frame)

等等。丢弃所有 cv* 函数并用它们的 cv:: 对应函数替换它们 （也许从头开始更好）

（顺便说一句，来自 SO 的代码 sn-ps 几乎总是过时的，请注意这一点）

并阅读docs（底部的教程链接）

---

整个摄像头捕获在 C++ 中归结为几行代码：

#include "opencv2/core/core.hpp"
#include "opencv2/imgproc/imgproc.hpp"
#include "opencv2/highgui/highgui.hpp"

using namespace cv;

int main()
{
    VideoCapture cap(0); // get first cam
    while( cap.isOpened() )
    {
        Mat frame;
        if ( ! cap.read(frame) ) // cam might need some warmup
            continue;

        // your processing goes here

        imshow("lalala",frame);
        if ( waitKey(10)==27 )
            break;
    }
    return 0;
}

Answer 2

@berak：好的，我删除了#include <opencv/highgui.h>。但仍然面临 cvtColor() 部分的问题。

C:\Users\PTOSH\Documents\tried.o:tried.cpp:(.text+0x75): 未定义引用cv::Mat::Mat(_IplImage const*, bool)' C:\Users\PTOSH\Documents\tried.o:tried.cpp:(.text+0x9b): undefined reference tocv::_OutputArray::_OutputArray(cv::Mat&)' C:\Users\PTOSH\Documents\tried.o:tried.cpp:(.text+0xae): 未定义引用cv::_InputArray::_InputArray(cv::Mat const&)' C:\Users\PTOSH\Documents\tried.o:tried.cpp:(.text+0xd3): undefined reference tocv::cvtColor(cv::_InputArray const&, cv::_OutputArray const&, int, int )'

@a-Jays：为什么不呢？无论如何，我删除了这个类，也许通过先开始测试 openCV 更容易。

感谢您的回复。

Answer 3

@berak：

如果你真的想使用 c++ api（你应该，因为旧 c-one 死了），

> CvCapture* capture;  // no, use: cv::VideoCapture
> 
> IplImage* frame = cvQueryFrame(capture);  // no, use: cv::Mat frame;
> capture.read(frame)

等等。丢弃所有 cv* 函数并用它们的 cv:: 替换它们 同行（也许从头开始更好）

（顺便说一句，来自 SO 的代码 sn-ps 几乎总是过时的，请注意 那个）

并阅读文档（底部的教程链接）

整个摄像头捕获在 C++ 中归结为几行代码：

> #include "opencv2/core/core.hpp"
> #include "opencv2/imgproc/imgproc.hpp"
> #include "opencv2/highgui/highgui.hpp"
> 
> using namespace cv;
> 
> int main() {
>     VideoCapture cap(0); // get first cam
>     while( cap.isOpened() )
>     {
>         Mat frame;
>         if ( ! cap.read(frame) ) // cam might need some warmup
>             continue;
> 
>         // your processing goes here
> 
>         imshow("lalala",frame);
>         if ( waitKey(10)==27 )
>             break;
>     }
>     return 0; }

---

您的代码在下面向我返回此错误，是否可能显示我的代码块设置中的链接失败？：

C:\Users\PTOSH\Documents\tried.o:tried.cpp:(.text+0x35): 未定义 参考cv::VideoCapture::VideoCapture(int)' C:\Users\PTOSH\Documents\tried.o:tried.cpp:(.text+0x57): undefined reference tocv::VideoCapture::read(cv::Mat&)' C:\Users\PTOSH\Documents\tried.o:tried.cpp:(.text+0x7b): 未定义 参考cv::_InputArray::_InputArray(cv::Mat const&)' C:\Users\PTOSH\Documents\tried.o:tried.cpp:(.text+0xb5): undefined reference tocv::imshow(std::string const&, cv::_InputArray const&)' C:\Users\PTOSH\Documents\tried.o:tried.cpp:(.text+0xd5): 未定义 参考cv::waitKey(int)' C:\Users\PTOSH\Documents\tried.o:tried.cpp:(.text+0x109): undefined reference tocv::VideoCapture::isOpened() const' C:\Users\PTOSH\Documents\tried.o:tried.cpp:(.text+0x120): 未定义 参考cv::VideoCapture::~VideoCapture()' C:\Users\PTOSH\Documents\tried.o:tried.cpp:(.text+0x162): undefined reference tocv::VideoCapture::~VideoCapture()'

感谢您的帮助。