目录
基本图像绘制涉及到的绘制函数如下:
- 用于绘制直线的line函数
- 用于绘制椭圆的ellipse函数
- 用于绘制矩形的rectangle函数
- 用于绘制圆的circle函数
- 用于绘制填充的多变形的fillPoly函数
下边代码WINDOW_WIDTH有如下的宏定义:
# define WINDOW_WIDTH 600 //定义窗口大小的宏
1、DrawEllipse()函数的写法
//-------------------------------【DrawEllipse( )函数】--------------------------------
// 描述:自定义的绘制函数,实现了绘制不同角度、相同尺寸的椭圆
//-----------------------------------------------------------------------------------------
void DrawEllipse( Mat img, double angle )
{
int thickness = 2;
int lineType = 8;
//调用OpenCV中ellipse函数
ellipse( img,
Point( WINDOW_WIDTH/2, WINDOW_WIDTH/2 ),
Size( WINDOW_WIDTH/4, WINDOW_WIDTH/16 ),
angle,
0,
360,
Scalar( 255, 129, 0 ),
thickness,
lineType );
}
上述代码,调用了OpenCV中ellipse函数:
- 椭圆绘制在img上
- 椭圆中心点为( WINDOW_WIDTH/2, WINDOW_WIDTH/2 )
- 大小位于矩形( WINDOW_WIDTH/4, WINDOW_WIDTH/16 )内
- 椭圆旋转角度为angle,扩展的弧度从0度到360度。从水平方向逆时针为正,顺时针为负
- 图色为Scalar(255, 129, 0)代表的蓝色
- 线宽(thickness)为2
- 线型(lineType)为8(8联通线型)
2、DrawFilledCircle()函数的写法
//-----------------------------------【DrawFilledCircle( )函数】---------------------------
// 描述:自定义的绘制函数,实现了实心圆的绘制
//-----------------------------------------------------------------------------------------
void DrawFilledCircle( Mat img, Point center )
{
int thickness = -1;
int lineType = 8;
circle( img,
center,
WINDOW_WIDTH/32,
Scalar( 0, 0, 255 ),
thickness,
lineType );
}
上述代码,调用了OpenCV中circle函数:
- 圆绘制在img上
- 圆中心点由center定义
- 圆半径为WINDOW_WIDTH/32
- 图形颜色为Scalar(0, 0, 255)代表的红色(BGR)
- 线宽(thickness)为-1,所以为实心圆,线粗为负值,则表示填充。
- 线型lineType)为8(8联通线型)
3、DrawPolygon()函数的写法
//-----------------------------------【DrawPolygon( )函数】--------------------------
// 描述:自定义的绘制函数,实现了凹多边形的绘制
//--------------------------------------------------------------------------------------
void DrawPolygon( Mat img )
{
int lineType = 8;
//创建一些点
Point rookPoints[1][20];
rookPoints[0][0] = Point( WINDOW_WIDTH/4, 7*WINDOW_WIDTH/8 );
rookPoints[0][1] = Point( 3*WINDOW_WIDTH/4, 7*WINDOW_WIDTH/8 );
rookPoints[0][2] = Point( 3*WINDOW_WIDTH/4, 13*WINDOW_WIDTH/16 );
rookPoints[0][3] = Point( 11*WINDOW_WIDTH/16, 13*WINDOW_WIDTH/16 );
rookPoints[0][4] = Point( 19*WINDOW_WIDTH/32, 3*WINDOW_WIDTH/8 );
rookPoints[0][5] = Point( 3*WINDOW_WIDTH/4, 3*WINDOW_WIDTH/8 );
rookPoints[0][6] = Point( 3*WINDOW_WIDTH/4, WINDOW_WIDTH/8 );
rookPoints[0][7] = Point( 26*WINDOW_WIDTH/40, WINDOW_WIDTH/8 );
rookPoints[0][8] = Point( 26*WINDOW_WIDTH/40, WINDOW_WIDTH/4 );
rookPoints[0][9] = Point( 22*WINDOW_WIDTH/40, WINDOW_WIDTH/4 );
rookPoints[0][10] = Point( 22*WINDOW_WIDTH/40, WINDOW_WIDTH/8 );
rookPoints[0][11] = Point( 18*WINDOW_WIDTH/40, WINDOW_WIDTH/8 );
rookPoints[0][12] = Point( 18*WINDOW_WIDTH/40, WINDOW_WIDTH/4 );
rookPoints[0][13] = Point( 14*WINDOW_WIDTH/40, WINDOW_WIDTH/4 );
rookPoints[0][14] = Point( 14*WINDOW_WIDTH/40, WINDOW_WIDTH/8 );
rookPoints[0][15] = Point( WINDOW_WIDTH/4, WINDOW_WIDTH/8 );
rookPoints[0][16] = Point( WINDOW_WIDTH/4, 3*WINDOW_WIDTH/8 );
rookPoints[0][17] = Point( 13*WINDOW_WIDTH/32, 3*WINDOW_WIDTH/8 );
rookPoints[0][18] = Point( 5*WINDOW_WIDTH/16, 13*WINDOW_WIDTH/16 );
rookPoints[0][19] = Point( WINDOW_WIDTH/4, 13*WINDOW_WIDTH/16 );
const Point* ppt[1] = { rookPoints[0] };
int npt[] = { 20 };
fillPoly( img,
ppt,
npt,
1,
Scalar( 255, 255, 255 ),
lineType );
}
上述代码,调用了OpenCV中fillPoly函数:
- 绘制在img上
- 多变形的顶点集为ppt
- 要绘制的多变形的顶点数目为npt
- 绘制多变形的数量为1
- 图形颜色为Scalar(255, 255, 255)代表的白色
- 线型(lineType)为8(8联通线型)
4、DrawLine()函数的写法
//-----------------------------------【DrawLine( )函数】--------------------------
// 描述:自定义的绘制函数,实现了线的绘制
//---------------------------------------------------------------------------------
void DrawLine( Mat img, Point start, Point end )
{
int thickness = 2;
int lineType = 8;
line( img,
start,
end,
Scalar( 0, 0, 0 ),
thickness,
lineType );
}
上述代码,调用了OpenCV中line函数
基本绘制图形代码:
主函数为(与上述函数组合起来):
//---------------------------------【头文件、命名空间包含部分】----------------------------
// 描述:包含程序所使用的头文件和命名空间
//------------------------------------------------------------------------------------------------
# include <opencv2/opencv.hpp>
using namespace cv;
//-----------------------------------【宏定义部分】--------------------------------------------
// 描述:定义一些辅助宏
//------------------------------------------------------------------------------------------------
#define WINDOW_NAME1 "【绘制图1】" //为窗口标题定义的宏
#define WINDOW_NAME2 "【绘制图2】" //为窗口标题定义的宏
#define WINDOW_WIDTH 600//定义窗口大小的宏
//--------------------------------【全局函数声明部分】-------------------------------------
// 描述:全局函数声明
//-----------------------------------------------------------------------------------------------
void DrawEllipse(Mat img, double angle);//绘制椭圆
void DrawFilledCircle(Mat img, Point center);//绘制圆
void DrawPolygon(Mat img);//绘制多边形
void DrawLine(Mat img, Point start, Point end);//绘制线段
//---------------------------------------【main( )函数】--------------------------------------
// 描述:控制台应用程序的入口函数,我们的程序从这里开始执行
//-----------------------------------------------------------------------------------------------
int main(void)
{
// 创建空白的Mat图像
Mat atomImage = Mat::zeros(WINDOW_WIDTH, WINDOW_WIDTH, CV_8UC3);
Mat rookImage = Mat::zeros(WINDOW_WIDTH, WINDOW_WIDTH, CV_8UC3);
// ---------------------<1>绘制化学中的原子示例图------------------------
//【1.1】先绘制出椭圆
DrawEllipse(atomImage, 90);
DrawEllipse(atomImage, 0); //0度是水平的
DrawEllipse(atomImage, 45); //水平自逆时针旋转
DrawEllipse(atomImage, -45); //水平自顺时针旋转
//【1.2】再绘制圆心
DrawFilledCircle(atomImage, Point(WINDOW_WIDTH / 2, WINDOW_WIDTH / 2));
// ----------------------------<2>绘制组合图-----------------------------
//【2.1】先绘制出多边性
DrawPolygon(rookImage);
// 【2.2】绘制矩形
rectangle(rookImage,
Point(0, 7 * WINDOW_WIDTH / 8),
Point(WINDOW_WIDTH, WINDOW_WIDTH),
Scalar(0, 255, 255),
-1,
8);
// 【2.3】绘制一些线段
DrawLine(rookImage, Point(0, 15 * WINDOW_WIDTH / 16), Point(WINDOW_WIDTH, 15 * WINDOW_WIDTH / 16));
DrawLine(rookImage, Point(WINDOW_WIDTH / 4, 7 * WINDOW_WIDTH / 8), Point(WINDOW_WIDTH / 4, WINDOW_WIDTH));
DrawLine(rookImage, Point(WINDOW_WIDTH / 2, 7 * WINDOW_WIDTH / 8), Point(WINDOW_WIDTH / 2, WINDOW_WIDTH));
DrawLine(rookImage, Point(3 * WINDOW_WIDTH / 4, 7 * WINDOW_WIDTH / 8), Point(3 * WINDOW_WIDTH / 4, WINDOW_WIDTH));
// ---------------------------<3>显示绘制出的图像------------------------
imshow(WINDOW_NAME1, atomImage);
moveWindow(WINDOW_NAME1, 0, 200); //设置窗口的位置和尺寸
imshow(WINDOW_NAME2, rookImage);
moveWindow(WINDOW_NAME2, WINDOW_WIDTH, 200);
waitKey(0);
return(0);
}
运行结果为:
moveWindow函数
上述代码设计moveWindow函数,对此函数如有疑问,请参考博文moveWindow函数用法详解