How to capture still image from webcam on linux

Question

I am trying to write a C++/Qt program for linux, where I take a still image photo from a webcam, make some transformations to a photo (cropping, resizing, etc.), and save it to

Answer 1

What about this program?

#include
using namespace cv;
int main()
{
    VideoCapture webcam;
    webcam.open(0);
    Mat frame;
    char key;

    while(true)
    {
        webcam >> frame;
        imshow("My Webcam",frame);
        key = waitKey(10);

        if(key=='s')
        break;
    }
    imwrite("webcam_capture.jpg", frame);
    webcam.release();
    return 0;
}

This will capture a picture of maximum size allowed by your webcam. Now you can add effects or resize the captured image with Qt. And OpenCV is very very easy to integrate with Qt, :)