OpenCV在图像上随机画直线、椭圆、多边形、圆、显示文字
代码如下：
/*** @file Drawing_2.cpp* @brief Simple sample code*/#include <opencv2/core.hpp>#include <opencv2/imgproc.hpp>#include <opencv2/highgui.hpp>#include <iostream>#include <stdio.h>using namespace cv;/// Global Variablesconst int NUMBER = 100;const int DELAY = 5;const int window_width = 900;const int window_height = 600;int x_1 = -window_width/2;int x_2 = window_width*3/2;int y_1 = -window_width/2;int y_2 = window_width*3/2;/// Function headersstatic Scalar randomColor( RNG& rng );int Drawing_Random_Lines( Mat image, char* window_name, RNG rng );int Drawing_Random_Rectangles( Mat image, char* window_name, RNG rng );int Drawing_Random_Ellipses( Mat image, char* window_name, RNG rng );int Drawing_Random_Polylines( Mat image, char* window_name, RNG rng );int Drawing_Random_Filled_Polygons( Mat image, char* window_name, RNG rng );int Drawing_Random_Circles( Mat image, char* window_name, RNG rng );int Displaying_Random_Text( Mat image, char* window_name, RNG rng );int Displaying_Big_End( Mat image, char* window_name, RNG rng );/*** @function main*/int main( void ){int c;/// Start creating a windowchar window_name[] = "Drawing_2 Tutorial";/// Also create a random object (RNG)RNG rng( 0xFFFFFFFF );/// Initialize a matrix filled with zerosMat image = Mat::zeros( window_height, window_width, CV_8UC3 );/// Show it in a window during DELAY msimshow( window_name, image );waitKey( DELAY );/// 画线c = Drawing_Random_Lines(image, window_name, rng);if( c != 0 ) return 0;/// 矩形c = Drawing_Random_Rectangles(image, window_name, rng);if( c != 0 ) return 0;/// 椭圆c = Drawing_Random_Ellipses( image, window_name, rng );if( c != 0 ) return 0;/// 多边形c = Drawing_Random_Polylines( image, window_name, rng );if( c != 0 ) return 0;/// 填充的多边形c = Drawing_Random_Filled_Polygons( image, window_name, rng );if( c != 0 ) return 0;/// 圆c = Drawing_Random_Circles( image, window_name, rng );if( c != 0 ) return 0;/// 随机位置显示文本c = Displaying_Random_Text( image, window_name, rng );if( c != 0 ) return 0;/// 显示文字c = Displaying_Big_End( image, window_name, rng );if( c != 0 ) return 0;waitKey(0);return 0;}/// Function definitions/*** @function randomColor* @brief Produces a random color given a random object*/static Scalar randomColor( RNG& rng ){int icolor = (unsigned) rng;return Scalar( icolor&255, (icolor>>8)&255, (icolor>>16)&255 );}/*** @function 随机画线*/int Drawing_Random_Lines( Mat image, char* window_name, RNG rng ){Point pt1, pt2;for( int i = 0; i < NUMBER; i++ ){pt1.x = rng.uniform( x_1, x_2 );pt1.y = rng.uniform( y_1, y_2 );pt2.x = rng.uniform( x_1, x_2 );pt2.y = rng.uniform( y_1, y_2 );line( image, pt1, pt2, randomColor(rng), rng.uniform(1, 10), 8 );imshow( window_name, image );if( waitKey( DELAY ) >= 0 ){ return -1; }}return 0;}/*** @function 画矩形*/int Drawing_Random_Rectangles( Mat image, char* window_name, RNG rng ){Point pt1, pt2;int lineType = 8;int thickness = rng.uniform( -3, 10 );for( int i = 0; i < NUMBER; i++ ){pt1.x = rng.uniform( x_1, x_2 );pt1.y = rng.uniform( y_1, y_2 );pt2.x = rng.uniform( x_1, x_2 );pt2.y = rng.uniform( y_1, y_2 );rectangle( image, pt1, pt2, randomColor(rng), MAX( thickness, -1 ), lineType );imshow( window_name, image );if( waitKey( DELAY ) >= 0 ){ return -1; }}return 0;}/*** @function 随机椭圆*/int Drawing_Random_Ellipses( Mat image, char* window_name, RNG rng ){int lineType = 8;for ( int i = 0; i < NUMBER; i++ ){Point center;center.x = rng.uniform(x_1, x_2);center.y = rng.uniform(y_1, y_2);Size axes;axes.width = rng.uniform(0, 200);axes.height = rng.uniform(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( window_name, image );if( waitKey(DELAY) >= 0 ){ return -1; }}return 0;}/*** @function 多边形*/int Drawing_Random_Polylines( Mat image, char* window_name, RNG rng ){int lineType = 8;for( int i = 0; i< NUMBER; i++ ){Point pt[2][3];pt[0][0].x = rng.uniform(x_1, x_2);pt[0][0].y = rng.uniform(y_1, y_2);pt[0][1].x = rng.uniform(x_1, x_2);pt[0][1].y = rng.uniform(y_1, y_2);pt[0][2].x = rng.uniform(x_1, x_2);pt[0][2].y = rng.uniform(y_1, y_2);pt[1][0].x = rng.uniform(x_1, x_2);pt[1][0].y = rng.uniform(y_1, y_2);pt[1][1].x = rng.uniform(x_1, x_2);pt[1][1].y = rng.uniform(y_1, y_2);pt[1][2].x = rng.uniform(x_1, x_2);pt[1][2].y = rng.uniform(y_1, y_2);const Point* ppt[2] = {pt[0], pt[1]};int npt[] = {3, 3};polylines(image, ppt, npt, 2, true, randomColor(rng), rng.uniform(1,10), lineType);imshow( window_name, image );if( waitKey(DELAY) >= 0 ){ return -1; }}return 0;}/*** @function 填充的多边形*/int Drawing_Random_Filled_Polygons( Mat image, char* window_name, RNG rng ){int lineType = 8;for ( int i = 0; i < NUMBER; i++ ){Point pt[2][3];pt[0][0].x = rng.uniform(x_1, x_2);pt[0][0].y = rng.uniform(y_1, y_2);pt[0][1].x = rng.uniform(x_1, x_2);pt[0][1].y = rng.uniform(y_1, y_2);pt[0][2].x = rng.uniform(x_1, x_2);pt[0][2].y = rng.uniform(y_1, y_2);pt[1][0].x = rng.uniform(x_1, x_2);pt[1][0].y = rng.uniform(y_1, y_2);pt[1][1].x = rng.uniform(x_1, x_2);pt[1][1].y = rng.uniform(y_1, y_2);pt[1][2].x = rng.uniform(x_1, x_2);pt[1][2].y = rng.uniform(y_1, y_2);const Point* ppt[2] = {pt[0], pt[1]};int npt[] = {3, 3};fillPoly( image, ppt, npt, 2, randomColor(rng), lineType );imshow( window_name, image );if( waitKey(DELAY) >= 0 ){ return -1; }}return 0;}/*** @function 圆*/int Drawing_Random_Circles( Mat image, char* window_name, RNG rng ){int lineType = 8;for (int i = 0; i < NUMBER; i++){Point center;center.x = rng.uniform(x_1, x_2);center.y = rng.uniform(y_1, y_2);circle( image, center, rng.uniform(0, 300), randomColor(rng),rng.uniform(-1, 9), lineType );imshow( window_name, image );if( waitKey(DELAY) >= 0 ){ return -1; }}return 0;}/*** @function 显示文本*/int Displaying_Random_Text( Mat image, char* window_name, RNG rng ){int lineType = 8;for ( int i = 1; i < NUMBER; i++ ){Point org;org.x = rng.uniform(x_1, x_2);org.y = rng.uniform(y_1, y_2);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( window_name, image );if( waitKey(DELAY) >= 0 ){ return -1; }}return 0;}显示文本Displaying_Big_End*/int Displaying_Big_End( Mat image, char* window_name, RNG ){Size textsize = getTextSize("OpenCV forever!", FONT_HERSHEY_COMPLEX, 3, 5, 0);Point org((window_width - textsize.width)/2, (window_height - textsize.height)/2);int lineType = 8;Mat image2;for( int i = 0; i < 255; i += 2 ){image2 = image - Scalar::all(i);putText( image2, "OpenCV forever!", org, FONT_HERSHEY_COMPLEX, 3,Scalar(i, i, 255), 5, lineType );imshow( window_name, image2 );if( waitKey(DELAY) >= 0 ){ return -1; }}return 0;}
结果：
随机画线:
矩形和椭圆
多边形
填充的多边形（三角形）和圆 最后，"Testing Text Rendering"*将会以不同的字体，大小、颜色出现在不同的位置.最后，显示”OpenCV forever!“
