Error: Undefined References
I am trying to obtain mouse coordinates on hover and click in c++, The code i use is following:
#include <opencv2/imgproc/imgproc.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <stdio.h>
using namespace cv;
Mat img;
void onMouse(int event, int x, int y, int flags, void* param)
{
char text[100];
Mat img2, img3;
img2 = img.clone();
if (event == CV_EVENT_LBUTTONDOWN)
{
Vec3b p = img2.at<Vec3b>(y,x);
sprintf(text, "R=%d, G=%d, B=%d", p[2], p[1], p[0]);
}
else if (event == CV_EVENT_RBUTTONDOWN)
{
cvtColor(img, img3, CV_BGR2HSV);
Vec3b p = img3.at<Vec3b>(y,x);
sprintf(text, "H=%d, S=%d, V=%d", p[0], p[1], p[2]);
}
else
sprintf(text, "x=%d, y=%d", x, y);
putText(img2, text, Point(5,15), FONT_HERSHEY_PLAIN, 1.0, CV_RGB(0,255,0));
imshow("image", img2);
}
int main(int argc, char** argv)
{
img = imread(argc == 2 ? argv[1] : "lena.jpg");
if (img.empty())
return -1;
namedWindow("image");
setMouseCallback("image", onMouse, 0);
imshow("image", img);
waitKey(0);
return 0;
}
But I am getting many errors..
C:\Users\NAVIGATOR\Desktop\t.o:t.cpp|| undefined reference to `cv::_OutputArray::_OutputArray(cv::Mat&)'|
C:\Users\NAVIGATOR\Desktop\t.o:t.cpp|| undefined reference to `cv::_InputArray::_InputArray(cv::Mat const&)'|
C:\Users\NAVIGATOR\Desktop\t.o:t.cpp|| undefined reference to `cv::cvtColor(cv::_InputArray const&, cv::_OutputArray const&, int, int)'|
C:\Users\NAVIGATOR\Desktop\t.o:t.cpp|| undefined reference to `cv::putText(cv::Mat&, std::string const&, cv::Point_<int>, int, double, cv::Scalar_<double>, int, int, bool)'|
C:\Users\NAVIGATOR\Desktop\t.o:t.cpp|| undefined reference to `cv::_InputArray::_InputArray(cv::Mat const&)'|
C:\Users\NAVIGATOR\Desktop\t.o:t.cpp|| undefined reference to `cv::imshow(std::string const&, cv::_InputArray const&)'|
C:\Users\NAVIGATOR\Desktop\t.o:t.cpp|| undefined reference to `cv::imread(std::string const&, int)'|
C:\Users\NAVIGATOR\Desktop\t.o:t.cpp|| undefined reference to `cv::namedWindow(std::string const&, int)'|
C:\Users\NAVIGATOR\Desktop\t.o:t.cpp|| undefined reference to `cv::setMouseCallback(std::string const&, void (*)(int, int, int, int, void*), void*)'|
C:\Users\NAVIGATOR\Desktop\t.o:t.cpp|| undefined reference to `cv::_InputArray::_InputArray(cv::Mat const&)'|
C:\Users\NAVIGATOR\Desktop\t.o:t.cpp|| undefined reference to `cv::imshow(std::string const&, cv::_InputArray const&)'|
C:\Users\NAVIGATOR\Desktop\t.o:t.cpp|| undefined reference to `cv::waitKey(int)'|
C:\Users\NAVIGATOR\Desktop\t.o:t.cpp:(.text$_ZN2cv3MatD1Ev[cv::Mat::~Mat()]+0x2b)||undefined reference to `cv::fastFree(void*)'|
(cv::Mat const&)]+0xfe)||undefined reference to `cv::Mat::copySize(cv::Mat const&)'|
C:\Users\NAVIGATOR\Desktop\t.o:t.cpp:(.text$_ZNK2cv3Mat5cloneEv[cv::Mat::clone() const]+0x61)||undefined reference to `cv::_OutputArray::_OutputArray(cv::Mat&)'|
C:\Users\NAVIGATOR\Desktop\t.o:t.cpp:(.text$_ZNK2cv3Mat5cloneEv[cv::Mat::clone() const]+0x73)||undefined reference to `cv::Mat::copyTo(cv::_OutputArray const&) const'|
C:\Users\NAVIGATOR\Desktop\t.o:t.cpp:(.text$_ZN2cv3Mat7releaseEv[cv::Mat::release()]+0x3c)||undefined reference to `cv::Mat ...
seems , you're not succesfully linking any opencv libs. opencv_core opencv_imgproc opencv_highgui needed here.