Regarding exmaples of Open CV

asked 2013-10-01 01:27:26 -0500

Harish gravatar image

Hi, I know this is basic question, but it would be helpfull if I get an answer:

include <opencv\cv.h>

include <opencv\highgui.h>

using namespace cv;

int main(int, char**) { int i=1; VideoCapture cap(0); if(!cap.isOpened()) return -1;

Mat frame, edges;
    cap >> frame;
    cvtColor(frame, edges, CV_BGR2GRAY);
    GaussianBlur(edges, edges, Size(7,7), 1.5, 1.5);

    Canny(edges, edges, 0, 30, 3);

        imshow("edges", edges);

    if(waitKey(30) >= 0) break;
return 0;


The above code executes but opens multiple windows. where the active window shows the camera video. the other windows have stills . I couldn't understand the problem here. I understand that imshow is the one which is used to show images, since it is in loop I get multiple windows. Imshow accepts 2 arguement and first one is window name and 2nd one is array. Since I have given name as "edges" in named window, so it should show camera video in only one window.

Could anyone help me what can be the problem? Thanks in advance....

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it does not here. is that the exact code ? what is int i=0; for ?

could you add your os / opencv version ?

berak gravatar imageberak ( 2013-10-01 04:33:01 -0500 )edit


Please ignore variable i, because I used as a flag and tried to execute imshow for once. So please ignore that...

the rest code is exact same..... I am using Windows 8 (9200 build) and opencv version 2.4.6.. Visual studio 2012

Harish gravatar imageHarish ( 2013-10-01 05:22:44 -0500 )edit

I understood the problem... And fixed it.. I declared string and passed it as the name and it worked.........

Harish gravatar imageHarish ( 2013-10-01 08:40:25 -0500 )edit