（10）绘制形状和文字
基本代码，这个我自己没有实验
1 #include "../common/common.hpp" 2 3 static Mat bgImage; 4 static void drawLines(); 5 static void drawRectangle(); 6 static void drawEllipse(); 7 static void drawCircle(); 8 static void drawPolygon(); 9 static void drawRandomLine(); 10 11 void main1_8(int argc, char** argv) 12 { 13 bgImage = imread(getCVImagesPath("images/test1.png"), IMREAD_COLOR); 14 drawLines(); 15 drawRectangle(); 16 drawEllipse(); 17 drawCircle(); 18 drawPolygon(); 19 //参数：Mat，文字(不识别中文?)，文字的位置(锚点?)，字体，缩放，颜色，线宽，线类型 20 putText(bgImage, "Hello OpenCV", Point(0, 200), CV_FONT_HERSHEY_COMPLEX, 1.0, Scalar(0), 3, LINE_8);//绘制文字 21 imshow("src", bgImage); 22 23 drawRandomLine(); 24 25 waitKey(0); 26 } 27 28 void drawLines()//绘制线条 29 { 30 Point p1 = Point(20, 30);//Point表示平面上的点，OpenCV中的这些坐标值都是相对于图像本身像素值的 31 Point p2; 32 p2.x = 400; 33 p2.y = 400; 34 Scalar color = Scalar(0, 0, 255); 35 line(bgImage, p1, p2, color, 10, LINE_AA);//绘制线条到Mat，10是线宽、LINE_4或LINE_8是带锯齿的，LINE_AA是抗锯齿的 36 } 37 38 void drawRectangle()//绘制矩形 39 { 40 //OpenCV的坐标系，原点在屏幕左上角，x朝右正，y朝下正 41 Rect rect = Rect(200, 100, 300, 300);//起始位置x、y，宽，高 42 Scalar color = Scalar(255, 0, 0); 43 rectangle(bgImage, rect, color, LINE_8);//绘制矩形到Mat，自带圆角。。 44 } 45 46 void drawEllipse()//绘制椭圆 47 { 48 int width = bgImage.cols; 49 int height = bgImage.rows; 50 Scalar color = Scalar(0, 255, 0); 51 //绘制椭圆，参数：Mat，中心点，椭圆的长短轴半径，椭圆的朝向(0表示水平)，起始角度，终点角度 52 ellipse(bgImage, Point(width / 2, height / 2), Size(width / 4, height / 8), 0, 0, 270, color, 2, LINE_8); 53 } 54 55 void drawCircle()//绘制圆 56 { 57 Scalar color = Scalar(0, 255, 255); 58 circle(bgImage, Point(bgImage.cols / 2, bgImage.rows / 2), 150, color, 2, LINE_8); 59 } 60 61 void drawPolygon()//绘制多边形，绘制的多边形是填充的 62 { 63 Point pts[1][5]; 64 pts[0][0] = Point(100, 100); 65 pts[0][1] = Point(100, 200); 66 pts[0][2] = Point(200, 200); 67 pts[0][3] = Point(200, 100); 68 pts[0][4] = Point(100, 100); 69 70 const Point * ppts[] = { pts[0] }; 71 int npt[] = { 5 }; 72 Scalar color = Scalar(255, 0, 255); 73 //参数：Mat，顶点数据指针，顶点个数，1表示只绘制一个contour(轮廓) 74 fillPoly(bgImage, ppts, npt, 1, color, LINE_8); 75 } 76 77 void drawRandomLine()//循环绘制随机位置随机颜色的线段 78 { 79 Mat randomLineMat = Mat::zeros(bgImage.size(), bgImage.type()); 80 RNG rng(12345);//生成高斯随机数，参数种子 81 Point p1, p2; 82 for (int i = 0; i < 100000; i++) 83 { 84 p1.x = rng.uniform(0, randomLineMat.cols);//生成正态分布 0-bgImage.cols 范围内的随机数 85 p1.y = rng.uniform(0, randomLineMat.rows); 86 p2.x = rng.uniform(0, randomLineMat.cols); 87 p2.y = rng.uniform(0, randomLineMat.rows); 88 Scalar color = Scalar(rng.uniform(0, 255), rng.uniform(0, 255), rng.uniform(0, 255)); 89 if (waitKey(50) > 0)//参数delay如果传0表示阻塞等待键盘事件，传大于0表示只阻塞等待delay毫秒，键盘无响应返回-1 90 { 91 break; 92 } 93 line(randomLineMat, p1, p2, color, 1, LINE_8); 94 imshow("randomLine", randomLineMat); 95 } 96 }
