新建空白图片

一、新建空白图片

Mat image = Mat(300,300,CV_8UC3,Scalar(0,0,255));

新建了一个图像image大小为300*300，矩阵元素为8位无符号char3通道，矩阵的内容为Scalar(0,0,255)红色

namedWindow("Test"); 新建一个Test窗口

imshow("Test",image); 在Test窗口中显示image

waitKey(0);  等待

二、画矩形，圆形等

rectangle(image,Point(50,50),Point(100,100),Scalar(255,0,0),2);

以image的（50，50）和（100，100）为对角线，线粗为2的(255,0,0)色矩形

圆circle(image,Point(100,100),50,Scalar(255,255,255),2);

三、载入、修改、保存图片

Mat image = imread("01.jpg");  //写绝对路径

rectangle(image,Point(50,50),Point(100,100),Scalar(255,0,0),2);

保存：imwrite("....",image);

四、定位框选图片

imgROI = image(Rect(40,40,40,40));

对应image图上的（40，40）为左上角，长宽为40的矩形

 五、基本图形的绘制

  1 #include
  2 #include
  3 #include
  4 using namespace cv;
  5 using namespace std;
  6 
  7 #define WINDOW_NAME1 "【绘制图1】"
  8 #define WINDOW_NAME2 "【绘制图2】"
  9 #define WINDOW_WIDTH 600
 10 
 11 
 12 void DrawEllipse(Mat img, double angle);
 13 void DrawFilledCircle(Mat img, Point center);
 14 void DrawPloygon(Mat img);
 15 void DrawLine(Mat img, Point start, Point end);
 16 
 17 int main() {
 18     //创建空白的Mat图像
 19     Mat atomImage = Mat::zeros(WINDOW_WIDTH, WINDOW_WIDTH, CV_8UC3);
 20     Mat rookImage = Mat::zeros(WINDOW_WIDTH, WINDOW_WIDTH, CV_8UC3);
 21 
 22     //【1.1】先绘制出椭圆
 23     DrawEllipse(atomImage, 90);
 24     DrawEllipse(atomImage, 0);
 25     DrawEllipse(atomImage, 45);
 26     DrawEllipse(atomImage, -45);
 27 
 28     //【1.2】绘制圆心
 29     DrawFilledCircle(atomImage, Point(WINDOW_WIDTH / 2, WINDOW_WIDTH / 2));
 30 
 31     DrawPloygon(rookImage);
 32 
 33     imshow(WINDOW_NAME1, atomImage);
 34     moveWindow(WINDOW_NAME1, 0, 200);
 35 
 36     imshow(WINDOW_NAME2, rookImage);
 37     moveWindow(WINDOW_NAME2, WINDOW_WIDTH, 200);
 38 
 39     waitKey();
 40     return 0;
 41 }
 42 
 43 void DrawEllipse(Mat img, double angle) {  //椭圆
 44     int thickness = 2;
 45     int lineType = 8;
 46 
 47     ellipse(img,
 48         Point(WINDOW_WIDTH / 2, WINDOW_WIDTH / 2),
 49         Size(WINDOW_WIDTH / 4, WINDOW_WIDTH / 16),
 50         angle,
 51         0,
 52         360,
 53         Scalar(255, 129, 0),
 54         thickness,
 55         lineType
 56         );
 57 }
 58 
 59 void DrawFilledCircle(Mat img, Point center) {  //实心圆
 60     int thickness = -1;
 61     int lineType = 8;
 62 
 63     circle(img,
 64         center,
 65         WINDOW_WIDTH / 32,
 66         Scalar(0, 0, 255),
 67         thickness,
 68         lineType);
 69 }
 70 
 71 void DrawPloygon(Mat img) {   //凹多边形
 72     int lineType = 8;
 73 
 74     //创建一些点
 75     Point rookPoint[1][20];
 76     rookPoint[0][0] = Point(WINDOW_WIDTH / 4, 7 * WINDOW_WIDTH / 8);
 77     rookPoint[0][1] = Point(3 * WINDOW_WIDTH / 4, 7 * WINDOW_WIDTH / 8);
 78     rookPoint[0][2] = Point(3 * WINDOW_WIDTH / 4, 13 * WINDOW_WIDTH / 16);
 79     rookPoint[0][3] = Point(11 * WINDOW_WIDTH / 16, 13 * WINDOW_WIDTH / 16);
 80 
 81     rookPoint[0][4] = Point(19 * WINDOW_WIDTH / 32, 3 * WINDOW_WIDTH / 8);
 82     rookPoint[0][5] = Point(3 * WINDOW_WIDTH / 4, 3 * WINDOW_WIDTH / 8);
 83     rookPoint[0][6] = Point(3 * WINDOW_WIDTH / 4, WINDOW_WIDTH / 8);
 84     rookPoint[0][7] = Point(26 * WINDOW_WIDTH / 40, WINDOW_WIDTH / 8);
 85 
 86     rookPoint[0][8] = Point(26 * WINDOW_WIDTH / 40, WINDOW_WIDTH / 4);
 87     rookPoint[0][9] = Point(22 * WINDOW_WIDTH / 40, WINDOW_WIDTH / 4);
 88     rookPoint[0][10] = Point(22 * WINDOW_WIDTH / 40, WINDOW_WIDTH / 8);
 89     rookPoint[0][11] = Point(18 * WINDOW_WIDTH / 40, WINDOW_WIDTH / 8);
 90 
 91     rookPoint[0][12] = Point(18 * WINDOW_WIDTH / 40, WINDOW_WIDTH / 4);
 92     rookPoint[0][13] = Point(14 * WINDOW_WIDTH / 40, WINDOW_WIDTH / 4);
 93     rookPoint[0][14] = Point(14 * WINDOW_WIDTH / 40, WINDOW_WIDTH / 8);
 94 
 95     rookPoint[0][15] = Point(WINDOW_WIDTH / 4, WINDOW_WIDTH / 8);
 96     rookPoint[0][16] = Point(WINDOW_WIDTH / 4, 3 * WINDOW_WIDTH / 8);
 97 
 98     rookPoint[0][17] = Point(13 * WINDOW_WIDTH / 32, 3 * WINDOW_WIDTH / 8);
 99     rookPoint[0][18] = Point(5 * WINDOW_WIDTH / 16, 13 * WINDOW_WIDTH / 16);
100     rookPoint[0][19] = Point(WINDOW_WIDTH / 4, 13 * WINDOW_WIDTH / 16);
101 
102     const Point* ppt[1] = { rookPoint[0] };
103     int npt[] = { 20 };
104 
105     fillPoly(img,
106         ppt,
107         npt,
108         1,
109         Scalar(255, 255, 255),
110         lineType);
111 }
112 
113 void DrawLine(Mat img, Point start, Point end) {    //线的绘制
114     int thickness = 2;
115     int lineType = 8;
116     line(img,
117         start,
118         end,
119         Scalar(0, 0, 0),
120         thickness,
121         lineType);
122 }

 

转载于:https://www.cnblogs.com/Nelsoner/p/6713324.html