Find Coner in Image

In digitam Image processing that can find Eigen value by Image process is calculated at least for the gradient matrices for corner.
example to use program
//CornerMinEigenVal
IplImage*pCornerMinEigenVal=cvCreateImage(cvGetSize(pCornerEigen),IPL_DEPTH_32F,1);
cvCornerMinEigenVal(pCornerEigen, pCornerMinEigenVal, 3, 7 );
cvNamedWindow("CornerMinEigen",CV_WINDOW_AUTOSIZE);
cvShowImage("CornerMinEigen", pCornerMinEigenVal);