opencv 绘图 cvLine cvRectangle cvCircle cvEllipse cvEllipseBox cvFillPoly cvConvexPoly cvPolyLine

常用宏定义：

#define CV_RGB( r, g, b )  cvScalar( (b), (g), (r), 0 )#define CV_FILLED -1#define CV_AA 16

#define cvDrawRect cvRectangle#define cvDrawLine cvLine#define cvDrawCircle cvCircle#define cvDrawEllipse cvEllipse#define cvDrawPolyLine cvPolyLine

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直线 cvLine()

/* Draws 4-connected, 8-connected or antialiased line segment connecting two points */CVAPI(void)  cvLine( CvArr* img, CvPoint pt1, CvPoint pt2,                     CvScalar color, int thickness CV_DEFAULT(1),                     int line_type CV_DEFAULT(8), int shift CV_DEFAULT(0) );

array：输入图像

pt1、pt2：直线的两点  CvPoint()结构

typedef struct CvPoint{    int x;    int y;}CvPoint;

color：边的颜色 CvScalar结构

typedef struct CvScalar{    double val[4];}CvScalar;

这种结构是四个双精度浮点型变量的集合，前三个分别代表红、绿、蓝通道

常用的便捷宏指令CV_RGB(r, g, b)

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矩形 cvRectagle()

/* Draws a rectangle given two opposite corners of the rectangle (pt1 & pt2),   if thickness<0 (e.g. thickness == CV_FILLED), the filled box is drawn */CVAPI(void)  cvRectangle( CvArr* img, CvPoint pt1, CvPoint pt2,                          CvScalar color, int thickness CV_DEFAULT(1),                          int line_type CV_DEFAULT(8),                          int shift CV_DEFAULT(0));

pt1和pt2为对顶角

thickness参数可设置为CV_FILL，其值是-1，表示使用color填充内部 在圆形和矩阵等很多封闭图形函数都可用

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圆形 cvCircle()

/* Draws a circle with specified center and radius.   Thickness works in the same way as with cvRectangle */CVAPI(void)  cvCircle( CvArr* img, CvPoint center, int radius,                       CvScalar color, int thickness CV_DEFAULT(1),                       int line_type CV_DEFAULT(8), int shift CV_DEFAULT(0));

center：圆中心 CvPoint()结构

radius：圆半径

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椭圆 cvEllipse() cvEllipseBox

/* Draws ellipse outline, filled ellipse, elliptic arc or filled elliptic sector,   depending on <thickness>, <start_angle> and <end_angle> parameters. The resultant figure   is rotated by <angle>. All the angles are in degrees */CVAPI(void)  cvEllipse( CvArr* img, CvPoint center, CvSize axes,                        double angle, double start_angle, double end_angle,                        CvScalar color, int thickness CV_DEFAULT(1),                        int line_type CV_DEFAULT(8), int shift CV_DEFAULT(0));

axes：CvSize()结构，height和width参数分别表示椭圆的长短半轴长

typedef struct CvSize{    int width;    int height;}CvSize;

angle：指偏离主轴的角度，从X轴算起，逆时针为正

start_angle和end_angle表示弧线可是和结束位置的角度。因此，一个完整的椭圆必须分别将这两个值分别设为0度和360度

CV_INLINE  void  cvEllipseBox( CvArr* img, CvBox2D box, CvScalar color,                               int thickness CV_DEFAULT(1),                               int line_type CV_DEFAULT(8), int shift CV_DEFAULT(0) ){    CvSize axes;    axes.width = cvRound(box.size.width*0.5);    axes.height = cvRound(box.size.height*0.5);    cvEllipse( img, cvPointFrom32f( box.center ), axes, box.angle,               0, 360, color, thickness, line_type, shift );}

box：CvBox2D结构 

typedef struct CvBox2D{    CvPoint2D32f center;  /* Center of the box.                          */    CvSize2D32f  size;    /* Box width and length.                       */    float angle;          /* Angle between the horizontal axis           */                          /* and the first side (i.e. length) in degrees */}CvBox2D;

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void paint(void){IplImage *src=cvLoadImage("lena.jpg");if (src == NULL){exit(0);}cvLine(src, cvPoint(3, 3), cvPoint(3, 300), CV_RGB(255, 255, 255), 1, 8);cvRectangle(src, cvPoint(10, 10), cvPoint(100, 100), CV_RGB(255, 255, 255), 1);cvCircle(src, cvPoint(350, 350), 50, CV_RGB(255, 255, 255), 1);cvEllipse(src, cvPoint(200, 200), cvSize(100, 50), 90, 0, 360, CV_RGB(255, 255, 255), 1, 8);CvSize2D32f size=cvSize2D32f(100, 50);CvBox2D box;box.center.x = 100;box.center.y = 300;box.size = size;box.angle = 90;cvEllipseBox(src, box, CV_RGB(255, 255, 255), 1, 8, 0);cvNamedWindow("src");cvShowImage("src", src);cvWaitKey(0);cvReleaseImage(&src);cvDestroyWindow("src");}

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/* Fills convex or monotonous polygon. */CVAPI(void)  cvFillConvexPoly( CvArr* img, const CvPoint* pts, int npts, CvScalar color,                               int line_type CV_DEFAULT(8), int shift CV_DEFAULT(0));

cvFillConvexPoly()一次只能画一个多边形，而且只能画凸多边形 

pts：存储点的数组

npts：存储点的数目

void convexPoly(void){IplImage *Image1;CvPoint PointArray1[6];int PolyVertexNumber;int Shift; CvSize ImageSize1 = cvSize(1000,700);     Image1 = cvCreateImage(ImageSize1, IPL_DEPTH_8U, 3);     PointArray1[0]=cvPoint(200,200);     PointArray1[1]=cvPoint(400,100);     PointArray1[2]=cvPoint(650,230);     PointArray1[3]=cvPoint(800,300);     PointArray1[4]=cvPoint(900,550);     PointArray1[5]=cvPoint(100,400);     CvScalar Color=CV_RGB(255,255,255);     PolyVertexNumber=6;     Shift=0;     cvFillConvexPoly(Image1,PointArray1,PolyVertexNumber,Color,CV_AA,Shift);     cvNamedWindow("FillConvexPoly",0);     cvShowImage("FillConvexPoly",Image1);     cvWaitKey(0);     cvSaveImage("poly.jpg",Image1);     cvReleaseImage(&Image1);}

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/* Fills an area bounded by one or more arbitrary polygons */CVAPI(void)  cvFillPoly( CvArr* img, CvPoint** pts, const int* npts,                         int contours, CvScalar color,                         int line_type CV_DEFAULT(8), int shift CV_DEFAULT(0) );/* Draws one or more polygonal curves */CVAPI(void)  cvPolyLine( CvArr* img, CvPoint** pts, const int* npts, int contours,                         int is_closed, CvScalar color, int thickness CV_DEFAULT(1),                         int line_type CV_DEFAULT(8), int shift CV_DEFAULT(0) );

npts：由记数点构成的数组，与多边形对应

is_closed为true：则起点和终点连线；否则，不连线

void fillPoly(void){IplImage *src=cvLoadImage("lena.jpg");if (src == NULL)exit(0);CvPoint** pt=new CvPoint*[1];pt[0]=new CvPoint[6];pt[0][0]=cvPoint(100, 100);pt[0][1]=cvPoint(400, 50);pt[0][2]=cvPoint(500, 400);pt[0][3]=cvPoint(300, 500);pt[0][4]=cvPoint(200, 300);pt[0][5]=cvPoint(50, 400);int *npt=new int[1];npt[0]=6;int contours=1;cvFillPoly(src, pt, npt, contours, CV_RGB(255, 255, 255), 8);//cvPolyLine(src, pt, npt, contours, 1, CV_RGB(255, 255, 255));//is_closed为true则将起点和终点连线//cvPolyLine(src, pt, npt, contours, 0, CV_RGB(255, 255, 255));//is_closed为false则不将起点和终点连线cvNamedWindow("src");cvShowImage("src", src);cvWaitKey(0);cvReleaseImage(&src);cvDestroyWindow("src");}