第三部分介绍如何进行简单的图像识别，并详细讲解如何识别线、点、圆和轮廓

边缘检测

int main(){
IplImage* girl = cvLoadImage("road.jpg", 0);
// 转换颜色为灰度
Mat boy;
//_start***************** ///
Mat cow = Mat(girl);
//Mat() 将 IplImage 转换为 Mat
imshow("cow", cow);
Canny(cow, boy, 125, 350);
//125< |像素 - 像素| <350 (滞后阈值)
imshow("boy", boy);
Mat Inv;
threshold(boy, Inv, 128, 255, THRESH_BINARY_INV);
// 反转颜色
//**end*********_** ///
duration = static_cast(getTickCount()) - duration;
duration /= getTickFrequency();
cout << duration;
//
imshow("Inv", Inv);
waitKey(0);

}