I'm a newbie to C++ and QT creator. While trying to compile a program using OpenCV 3.0.0, on QT creator 3.4.1, on Mac OS X 10.10.4 I get the 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 is "<< 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) {}
// extra constructor for 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 the distance from target color.
int getDistanceToTargetColor(const cv::Vec3b& color) const {
return getColorDistance(color, target);
}
// Computes the city-block distance between two 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 the image. Returns a 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 with target color
cv::absdiff(input,cv::Scalar(target),output);
// split the channels into 3 images
std::vector<cv::Mat> images;
cv::split(output,images);
// add the 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 be < 256)
255, // max value
cv::THRESH_BINARY_INV); // thresholding type
return output;
}
// Getters and setters
// Sets the color distance threshold.
// Threshold must be positive, otherwise distance threshold
// is set to 0.
void setColorDistanceThreshold(int distance) {
if (distance<0)
distance=0;
maxDist= distance;
}
// Gets the color distance threshold
int getColorDistanceThreshold() const {
return maxDist;
}
// Sets the color to be 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 the target to Lab color space
cv::cvtColor(tmp, tmp, CV_BGR2Lab);
target = tmp.at<cv::Vec3b>(0, 0);
}
}
// Sets the color to be detected
void setTargetColor(cv::Vec3b color) {
target= color;
}
// Gets the color to be detected
cv::Vec3b getTargetColor() const {
return target;
}
};
#endif
Compiler output
14:27:06: Running steps for 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 for architecture x86_64:
"ColorDetector::process(cv::Mat const&)", referenced from:
MainWindow::on_pushButton_2_clicked() in mainwindow.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make: *** [QTopenCV.app/Contents/MacOS/QTopenCV] Error 1
14:27:06: The process "/usr/bin/make" exited with 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 I was trying to do is: Give a color, find it and its nearby color (within a threshold) in an image, mask those color in white. The function was contained in the header file colorselection.h . Please help me!
