c++ - Qt Creater, Mac OS X: Error: "Symbol(s) not found" when calling function from included header -

i'm newbie c++ , qt creator. while trying compile program using opencv 3.0.0, on qt creator 3.4.1, on mac os x 10.10.4 following errors:

atopencv.pro

qt       += core gui  greaterthan(qt_major_version, 4): qt += widgets  target = qtopencv template = app   sources += main.cpp\         mainwindow.cpp  headers  += mainwindow.h \     colordetector.h  forms    += mainwindow.ui qmake_macosx_deployment_target = 10.10  includepath += /usr/local/include/  libs += -l/usr/local/lib libs += -lopencv_core libs += -lopencv_imgproc libs += -lopencv_highgui libs += -lopencv_ml libs += -lopencv_video libs += -lopencv_features2d libs += -lopencv_calib3d libs += -lopencv_objdetect libs += -lopencv_flann libs += -lopencv_imgcodecs 

mainwindow.cpp

#include "mainwindow.h" #include "ui_mainwindow.h"  #include <opencv2/opencv.hpp> #include <qfiledialog> #include "colordetector.h"  mainwindow::mainwindow(qwidget *parent)    : qmainwindow(parent), ui(new ui::mainwindow)    {       ui->setupui(this);       ui->pushbutton_2->setenabled(false);     }    mainwindow::~mainwindow()    {  delete ui; } void mainwindow::on_pushbutton_clicked() {      qstring filename = qfiledialog::getopenfilename(this, tr("open image"), ".", tr("image files (*.png *.jpg *.bmp)"));           image= cv::imread(filename.toutf8().data());            if (image.data)           {               ui->pushbutton_2->setenabled(true);           }  }  void mainwindow::on_pushbutton_2_clicked() {     colordetector cdetect;     cdetect.settargetcolor(230, 190, 130);     cv::mat result1;     double duration;     duration= static_cast<double>(cv::gettickcount());     result1= cdetect.process(image);     duration= static_cast<double>(cv::gettickcount()) - duration;     duration /= cv::gettickfrequency();     std::cout <<"duration "<< duration << " second" << std::endl;     cv::imshow("final", result1); } 

colordetector.h

if !defined colordetect #define colordetect  #include <opencv2/core/core.hpp> #include <opencv2/imgproc/imgproc.hpp>  class colordetector {    private:        // minimum acceptable distance       int maxdist;        // target color       cv::vec3b target;        // image containing color converted image       cv::mat converted;       bool uselab;        // image containing resulting binary map       cv::mat result;    public:        // empty constructor       // default parameter initialization here       colordetector() : maxdist(100), target(0,0,0), uselab(false) {}        // constructor lab color space example       colordetector(bool uselab) : maxdist(100), target(0,0,0), uselab(uselab) {}        // full constructor       colordetector(uchar blue, uchar green, uchar red, int mxdist=100, bool uselab=false): maxdist(mxdist), uselab(uselab) {            // target color           settargetcolor(blue, green, red);       }        // computes distance target color.       int getdistancetotargetcolor(const cv::vec3b& color) const {           return getcolordistance(color, target);       }        // computes city-block distance between 2 colors.       int getcolordistance(const cv::vec3b& color1, const cv::vec3b& color2) const {            return abs(color1[0]-color2[0])+                     abs(color1[1]-color2[1])+                     abs(color1[2]-color2[2]);            // or:           // return static_cast<int>(cv::norm<int,3>(cv::vec3i(color[0]-color2[0],color[1]-color2[1],color[2]-color2[2])));            // or:           // cv::vec3b dist;           // cv::absdiff(color,color2,dist);           // return cv::sum(dist)[0];       }        // processes image. returns 1-channel binary image.       cv::mat process(const cv::mat &image);        cv::mat operator()(const cv::mat &image) {            cv::mat input;           input = image;           if (uselab) { // lab conversion               cv::cvtcolor(image, input, cv_bgr2lab);           }            cv::mat output;           // compute absolute difference target color           cv::absdiff(input,cv::scalar(target),output);           // split channels 3 images           std::vector<cv::mat> images;           cv::split(output,images);           // add 3 channels (saturation might occurs here)           output= images[0]+images[1]+images[2];           // apply threshold           cv::threshold(output,  // input image                       output,  // output image                       maxdist, // threshold (must < 256)                       255,     // max value                  cv::thresh_binary_inv); // thresholding type            return output;       }        // getters , setters        // sets color distance threshold.       // threshold must positive, otherwise distance threshold       // set 0.       void setcolordistancethreshold(int distance) {            if (distance<0)               distance=0;           maxdist= distance;       }        // gets color distance threshold       int getcolordistancethreshold() const {            return maxdist;       }        // sets color detected       void settargetcolor(uchar blue, uchar green, uchar red) {            // bgr order           target = cv::vec3b(blue, green, red);            if (uselab) {               // temporary 1-pixel image               cv::mat tmp(1, 1, cv_8uc3);               tmp.at<cv::vec3b>(0, 0) = cv::vec3b(blue, green, red);                // converting target lab color space               cv::cvtcolor(tmp, tmp, cv_bgr2lab);                target = tmp.at<cv::vec3b>(0, 0);           }       }        // sets color detected       void settargetcolor(cv::vec3b color) {            target= color;       }        // gets color detected       cv::vec3b gettargetcolor() const {            return target;       } };   #endif 

compiler output

14:27:06: running steps project qtopencv... 14:27:06: configuration unchanged, skipping qmake step. 14:27:06: starting: "/usr/bin/make"  /applications/xcode.app/contents/developer/toolchains/xcodedefault.xctoolchain/usr/bin/clang++ -headerpad_max_install_names -wl,-syslibroot,/applications/xcode.app/contents/developer/platforms/macosx.platform/developer/sdks/macosx10.10.sdk -mmacosx-version-min=10.10 -wl,-rpath,/users/apple/qt5.4.2/5.4/clang_64/lib -o qtopencv.app/contents/macos/qtopencv main.o mainwindow.o moc_mainwindow.o   -f/users/apple/qt5.4.2/5.4/clang_64/lib -l/usr/local/lib -lopencv_core -lopencv_imgproc -lopencv_highgui -lopencv_ml -lopencv_video -lopencv_features2d -lopencv_calib3d -lopencv_objdetect -lopencv_flann -lopencv_imgcodecs -framework qtwidgets -framework qtgui -framework qtcore -framework diskarbitration -framework iokit -framework opengl -framework agl  undefined symbols architecture x86_64:   "colordetector::process(cv::mat const&)", referenced from:       mainwindow::on_pushbutton_2_clicked() in mainwindow.o ld: symbol(s) not found architecture x86_64 clang: error: linker command failed exit code 1 (use -v see invocation) make: *** [qtopencv.app/contents/macos/qtopencv] error 1 14:27:06: process "/usr/bin/make" exited code 2. error while building/deploying project qtopencv (kit: desktop qt 5.4.2 clang 64bit) when executing step "make" 14:27:06: elapsed time: 00:00. 

what trying is: give color, find , nearby color (within threshold) in image, mask color in white. function contained in header file colorselection.h . please me!

undefined symbols architecture x86_64: "colordetector::process(cv::mat const&)

this telling implementation function colordetector::process can't found.

mainwindow::on_pushbutton_2_clicked() in mainwindow.o

and function being called in mainwindow::on_pushbutton_2_clicked()

you've declared in colordetector.h, either implementation missing in colordetector.cpp, or doesn't match definition declared in header.