undefined ссылка на cv :: calcOpticalFlowPyrLK

Question

Я изучаю OpenCV прямо сейчас, и я тестирую доступную демоверсию LK. Я довольно новичок в программировании, поэтому не знаю, что случилось.

Я получил эти вопросы:

C:\Qt\projects\build-lkdemo-Desktop_Qt_5_3_MinGW_32bit-Debug\debug\main.o:-1: In function `Z5qMainiPPc': 
C:\Qt\projects\lkdemo\main.cpp:96: error: undefined reference to `cv::calcOpticalFlowPyrLK(cv::_InputArray const&, cv::_InputArray const&, cv::_InputArray const&, cv::_OutputArray const&, cv::_OutputArray const&, cv::_OutputArray const&, cv::Size_<int>, int, cv::TermCriteria, int, double)' 
collect2.exe:-1: error: error: ld returned 1 exit status 

А вот код:

#include <QApplication> 
#include "opencv2/video/tracking.hpp" 
#include "opencv2/imgproc/imgproc.hpp" 
#include "opencv2/highgui/highgui.hpp" 

#include <iostream> 
#include <ctype.h> 

using namespace cv; 
using namespace std; 

static void help() 
{ 
    // print a welcome message, and the OpenCV version 
    cout << "\nThis is a demo of Lukas-Kanade optical flow lkdemo(),\n" 
      "Using OpenCV version %s\n" << CV_VERSION << "\n" 
      << endl; 

    cout << "\nHot keys: \n" 
      "\tESC - quit the program\n" 
      "\tr - auto-initialize tracking\n" 
      "\tc - delete all the points\n" 
      "\tn - switch the \"night\" mode on/off\n" 
      "To add/remove a feature point click it\n" << endl; 
} 

Point2f point; 
bool addRemovePt = false; 

static void onMouse(int event, int x, int y, int /*flags*/, void* /*param*/) 
{ 
    if(event == CV_EVENT_LBUTTONDOWN) 
    { 
     point = Point2f((float)x,(float)y); 
     addRemovePt = true; 
    } 
} 

int main(int argc, char *argv[]) 
{ 
    QApplication a(argc, argv); 
    VideoCapture cap; 
    TermCriteria termcrit(CV_TERMCRIT_ITER|CV_TERMCRIT_EPS,20,0.03); 
    Size subPixWinSize(10,10), winSize(31,31); 

    const int MAX_COUNT = 500; 
    bool needToInit = false; 
    bool nightMode = false; 

    if(argc == 1 || (argc == 2 && strlen(argv[1]) == 1 && isdigit(argv[1][0]))) 
     cap.open(argc == 2 ? argv[1][0] - '0' : 0); 
    else if(argc == 2) 
     cap.open(argv[1]); 

    if(!cap.isOpened()) 
    { 
     cout << "Could not initialize capturing...\n"; 
     return a.exec(); 
    } 

    help(); 

    namedWindow("LK Demo", 1); 
    setMouseCallback("LK Demo", onMouse, 0); 

    Mat gray, prevGray, image; 
    vector<Point2f> points[2]; 

    for(;;) 
    { 
     Mat frame; 
     cap >> frame; 
     if(frame.empty()) 
      break; 

     frame.copyTo(image); 
     cvtColor(image, gray, CV_BGR2GRAY); 

     if(nightMode) 
      image = Scalar::all(0); 

     if(needToInit) 
     { 
      // automatic initialization 
      goodFeaturesToTrack(gray, points[1], MAX_COUNT, 0.01, 10, Mat(), 3, 0, 0.04); 
      cornerSubPix(gray, points[1], subPixWinSize, Size(-1,-1), termcrit); 
      addRemovePt = false; 
     } 
     else if(!points[0].empty()) 
     { 
      vector<uchar> status; 
      vector<float> err; 
      if(prevGray.empty()) 
       gray.copyTo(prevGray); 
      calcOpticalFlowPyrLK(prevGray, gray, points[0], points[1], status, err, winSize, 
           3, termcrit, 0, 0.001); 
      size_t i, k; 
      for(i = k = 0; i < points[1].size(); i++) 
      { 
       if(addRemovePt) 
       { 
        if(norm(point - points[1][i]) <= 5) 
        { 
         addRemovePt = false; 
         continue; 
        } 
       } 

       if(!status[i]) 
        continue; 

       points[1][k++] = points[1][i]; 
       circle(image, points[1][i], 3, Scalar(0,255,0), -1, 8); 
      } 
      points[1].resize(k); 
     } 

     if(addRemovePt && points[1].size() < (size_t)MAX_COUNT) 
     { 
      vector<Point2f> tmp; 
      tmp.push_back(point); 
      cornerSubPix(gray, tmp, winSize, cvSize(-1,-1), termcrit); 
      points[1].push_back(tmp[0]); 
      addRemovePt = false; 
     } 

     needToInit = false; 
     imshow("LK Demo", image); 

     char c = (char)waitKey(10); 
     if(c == 27) 
      break; 
     switch(c) 
     { 
     case 'r': 
      needToInit = true; 
      break; 
     case 'c': 
      points[1].clear(); 
      break; 
     case 'n': 
      nightMode = !nightMode; 
      break; 
     default: 
      ; 
     } 

     std::swap(points[1], points[0]); 
     swap(prevGray, gray); 
    } 

    return a.exec(); 
} 

Что мне нужно знать, чтобы решить эту проблему?

Edit 1: Вот мои .pro:

#------------------------------------------------- 
# 
# Project created by QtCreator 2015-02-26T10:12:31 
# 
#------------------------------------------------- 

INCLUDEPATH += C:\opencv-mingw\install\include 
LIBS += -L"C:/opencv-mingw/install/x64/mingw/bin" 
LIBS += -lopencv_core249 -lopencv_highgui249 -lopencv_imgproc249 

QT  += core gui 

greaterThan(QT_MAJOR_VERSION, 4): QT += widgets 

TARGET = lkdemo 
TEMPLATE = app 


SOURCES += main.cpp 

Answer 1

cv::calcOpticalFlowPyrLK() является частью video модуля. Вы должны добавить opencv_videoXXXXd.lib и/или opencv_videoXXXX.lib к компоновщику.

т.е .:

LIBS += -lopencv_core249 -lopencv_highgui249 -lopencv_imgproc249 -lopencv_video249