Configure OpenCV 2.4 for Qt Creator on Ubuntu

First install Qt creator using Ubuntu Software Center

Open Qt Creator

File --> New file or project
Qt Widget Project --> Qt GUI Application --> Choose

Click Next for all.

Open .pro file and add the following lines

INCLUDEPATH += /usr/local/include/opencv
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_contrib
LIBS += -lopencv_legacy
LIBS += -lopencv_flann
LIBS += -lopencv_nonfree

Save it.

Open .ui file.

Drag and drop a PushButton to window.
Click PushButton and chage the follwong properties

• objectName: btnDisplay
• text: Display

Right click PushButton --> Go to slot --> clicked() --> Ok

Include the following

#include <cv.h>
#include <highgui.h>

Add the following code

void MainWindow::on_btnDisplay_clicked()
{
    cv::namedWindow("Disp");
    cv::VideoCapture cap(0);
    cv::Mat frame;
    do{
        cap >> frame;
        imshow("Disp",frame);
    }while(cv::waitKey(30)<0);
    cv::destroyAllWindows();
}

Run it. You will see yourself on the screen, when you click Display button !!!