#include#include int main(int argc, char** argv){ CvMat* mat = cvCreateMat(100,100, CV_8SC3); cvZero(mat); cvCircle(mat, cvPoint(50, 50), 30, cvScalar(0xff, 0xff, 0xff)); cvNamedWindow("cvCircle",CV_WINDOW_AUTOSIZE); cvShowImage("cvCircle", mat); cvWaitKey(0);}