OpenCv学习笔记(六)：使用opencv画线、矩形、椭圆、多边形线、多边形体等

1、在 mfc 中我们经常会画线、矩形、椭圆、多边形等几何结构，opencv 为我们供应了已经封装好的函数来实现该功能，而且简洁便利。下面供应一下例子，是 opencv 安装以后自带的小程序，学习完现在的程序你可以学会以下学问：（1）生成随机数，使用 rng 类（2） 画线（3）画矩形（4）画椭圆（5）画圆（6)输出文字、文本(7)假如不生疏 opencv 的还能学会 point 结构体的使用，scalar 结构使用。具体可以看下面的小例子。在vs2010 下运行一下就会明白了！#include “stdafx.h“#include “opencv2/core/core.hpp“ #include

2、 “opencv2/highgui/highgui.hpp“ #include <stdio.h>using namespace cv; void help()printf(“nthis program demonstrates opencv drawing and text output functions.n“ “usage:n“ ./drawingn“);static scalar randomcolor(rng& rng)int icolor = (unsigned)rng;return scalar(icolor&255, (icolor>>8

3、)&255, (icolor>>16)&255);int main()help();char wndname = “drawing demo“; const int number = 100;const int delay = 5;int linetype = cv_aa; / change it to 8 to see non-antialiased graphics int i, width = 1000, height = 700;int x1 = -width/2, x2 = width*3/2, y1 = -height/2, y2 = height*3/

4、2; rng rng(0xffffffff);mat image = mat:zeros(height, width, cv_8uc3); imshow(wndname, image);waitkey(delay);for (i = 0; i < number; i+)point pt1, pt2;pt1.x = rng.uniform(x1, x2); pt1.y = rng.uniform(y1, y2); pt2.x = rng.uniform(x1, x2); pt2.y = rng.uniform(y1, y2);line( image, pt1, pt2, randomcol

5、or(rng), rng.uniform(1,10), linetype ); imshow(wndname, image);if(waitkey(delay) >= 0)return 0;for (i = 0; i < number; i+)point pt1, pt2;pt1.x = rng.uniform(x1, x2); pt1.y = rng.uniform(y1, y2); pt2.x = rng.uniform(x1, x2); pt2.y = rng.uniform(y1, y2);int thickness = rng.uniform(-3, 10);rectan

6、gle( image, pt1, pt2, randomcolor(rng), max(thickness, -1), linetype ); imshow(wndname, image);if(waitkey(delay) >= 0)return 0;for (i = 0; i < number; i+)point center;center.x = rng.uniform(x1, x2); center.y = rng.uniform(y1, y2); size axes;axes.width = rng.uniform(0, 200); axes.height = rng.u

7、niform(0, 200); double angle = rng.uniform(0, 180);ellipse( image, center, axes, angle, angle - 100, angle + 200, randomcolor(rng), rng.uniform(-1,9), linetype ); imshow(wndname, image);if(waitkey(delay) >= 0)return 0;for (i = 0; i< number; i+)point pt23;pt00.x = rng.uniform(x1, x2);pt00.y = r

8、ng.uniform(y1, y2);pt01.x = rng.uniform(x1, x2);pt01.y = rng.uniform(y1, y2);pt02.x = rng.uniform(x1, x2);pt02.y = rng.uniform(y1, y2);pt10.x = rng.uniform(x1, x2);pt10.y = rng.uniform(y1, y2);pt11.x = rng.uniform(x1, x2);pt11.y = rng.uniform(y1, y2);pt12.x = rng.uniform(x1, x2);pt12.y = rng.uniform

9、(y1, y2);const point* ppt2 = pt0, pt1; int npt = 3, 3;polylines(image, ppt, npt, 2, true, randomcolor(rng), rng.uniform(1,10), linetype); imshow(wndname, image);if(waitkey(delay) >= 0)return 0;for (i = 0; i< number; i+)point pt23;pt00.x = rng.uniform(x1, x2);pt00.y = rng.uniform(y1, y2);pt01.x

10、 = rng.uniform(x1, x2);pt01.y = rng.uniform(y1, y2);pt02.x = rng.uniform(x1, x2);pt02.y = rng.uniform(y1, y2);pt10.x = rng.uniform(x1, x2);pt10.y = rng.uniform(y1, y2);pt11.x = rng.uniform(x1, x2);pt11.y = rng.uniform(y1, y2);pt12.x = rng.uniform(x1, x2);pt12.y = rng.uniform(y1, y2);const point* ppt

11、2 = pt0, pt1; int npt = 3, 3;fillpoly(image, ppt, npt, 2, randomcolor(rng), linetype); imshow(wndname, image);if(waitkey(delay) >= 0)return 0;for (i = 0; i < number; i+)point center;center.x = rng.uniform(x1, x2); center.y = rng.uniform(y1, y2);circle(image, center, rng.uniform(0, 300), random

12、color(rng), rng.uniform(-1, 9), linetype);imshow(wndname, image); if(waitkey(delay) >= 0)return 0;for (i = 1; i < number; i+)point org;org.x = rng.uniform(x1, x2); org.y = rng.uniform(y1, y2);puttext(image, “testing text rendering“, org, rng.uniform(0,8), rng.uniform(0,100)*0.05+0.1, randomcolor(rng), rng.uniform(1, 10), linetype); imshow(wndname, image);if(waitkey(delay) >= 0)return 0;size textsize = gettextsize(“opencv forever!“, cv_font_hershey_complex, 3, 5, 0);point org(width - textsize.width)/2, (height - textsize.height)/2); mat image2;for( i = 0; i < 255; i += 2 )image2