OpenCV will load image but not display it

Question

I am using CMake and OpenCV with C++ and am just trying to run a simple program:

#include "opencv/highgui.h"
#include "opencv/highgui.hpp"
#include "opencv/cv.h"
#include "opencv/cxcore.h"
#include "opencv/cxcore.hpp"
#include <stdio.h>
#include <iostream>

using namespace cv;
using namespace std;

int main()
{

   Mat image = imread("test.jpg", CV_LOAD_IMAGE_UNCHANGED);
   if (!image.data) //check whether the image is loaded or not
   {
         cout << "Image cannot be loaded." << endl;
   }
   else
   {
        cout<<"Image can be loaded."<<endl;
        cout<<"Size is "<<image.size().height<<","<<image.size().width<<endl;
        namedWindow( "Display window", CV_WINDOW_AUTOSIZE );
        imshow( "Display Image", image );
    }
}

When I cmake, I get no errors, and when I run the program by doing ./test, I get "Image can be loaded" along with the correct size of the image.

Why won't my program create a new window which displays the image?

Thank you!

Sorry for not including this in the original question. 2.0.0 — user8333141, Jul 21 '16 at 15:09
Possible duplicate of [Configuring an c++ OpenCV project with Cmake](http://stackoverflow.com/questions/13970377/configuring-an-c-opencv-project-with-cmake) — Richard Dally, Jul 21 '16 at 15:10
@drescherjm Sorry, you're right. I copied an error that I got rid of while writing the post. Edited. — user8333141, Jul 21 '16 at 15:10
The example you are refereing to uses OpenCv2. So yeah as @drescherjm suggested, upgrade your OpenCv — Khalil Khalaf, Jul 21 '16 at 15:16
IMO 2.0.0 is too old for you to obtain any support from the community. You should seriously update to at least 2.4.13 (although 3.1.0 is stable right now, and should be preferred over 2.x.x). — E_net4, Jul 21 '16 at 15:16

score 3 · Accepted Answer · edited Nov 02 '16 at 20:01

3

use cv::waitKey() after imshow. This is needed to proceed openCV rendering.

use waitKey(0) to pause until a key is pressed or waitKey(1) to pause as short as possible.

For further reference.

edited Nov 02 '16 at 20:01

ThreeFx

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answered Jul 21 '16 at 17:44

Micka

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OpenCV will load image but not display it

1 Answers1