对视频进行转成灰度图，并进行canny边缘检测，并将3个影像合到一个影像中显示。
VideoCapture cap("D:\\编程\\opencv\\opencv\\opencv\\sources\\samples\\data\\vtest.avi");
Mat m1,m2,m3,m_all;
auto width=cap.get(CAP_PROP_FRAME_WIDTH);
auto height = cap.get(CAP_PROP_FRAME_HEIGHT);
while (true)
{
cap >> m1;
cvtColor(m1, m2, COLOR_RGB2GRAY);
Canny(m2, m3, 200, 300);
cvtColor(m2, m2, COLOR_GRAY2RGB);
cvtColor(m3, m3, COLOR_GRAY2RGB);//single way to 3 ways
m_all.create(height, width*3, m1.type());
putText(m1, "RGB影像", Point(500, 100), 1,99, Scalar(255, 0, 0));
putText(m2, "GRAY影像", Point(500, 100), 1, 99, Scalar(0, 255, 0));
putText(m3, "Canny影像", Point(500, 100), 1, 99, Scalar(0,0, 255));
m1.copyTo(m_all(Rect(0, 0, width, height)));
m2.copyTo(m_all(Rect(width, 0, width, height)));
m3.copyTo(m_all(Rect(width*2,0, width, height)));
namedWindow("final", 0);
imshow("final", m_all);
/*Ptr<Mat> a1, a2, a3;
a1 = &m1; a2 = &m2; a3 = &m3;
a1.*/
if (waitKey(100) == 27) break;
}效果如下
