怎么用C++ OpenCV绘制几何图形

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具体内容如下

绘制几何图形

• 直线

• 矩形

• 多边形

• 圆形

• 椭圆

• 文字
  

API

直线

CV_EXPORTS_W void line(InputOutputArray img, Point pt1, Point pt2, const Scalar& color,                     int thickness = 1, int lineType = LINE_8, int shift = 0);

矩形

CV_EXPORTS_W void rectangle(InputOutputArray img, Point pt1, Point pt2,                          const Scalar& color, int thickness = 1,                          int lineType = LINE_8, int shift = 0);

上方函数通过两点确定矩形的位置和大小，下方函数则是通过矩形对象 Rect 来确定。

CV_EXPORTS_W void rectangle(InputOutputArray img, Rect rec,                          const Scalar& color, int thickness = 1,                          int lineType = LINE_8, int shift = 0);

多边形

CV_EXPORTS void polylines(InputOutputArray img, const Point* const* pts, const int* npts,                          int ncontours, bool isClosed, const Scalar& color,                          int thickness = 1, int lineType = LINE_8, int shift = 0 );

CV_EXPORTS_W void polylines(InputOutputArray img, InputArrayOfArrays pts,                            bool isClosed, const Scalar& color,                            int thickness = 1, int lineType = LINE_8, int shift = 0 );

圆形

CV_EXPORTS_W void circle(InputOutputArray img, Point center, int radius,                       const Scalar& color, int thickness = 1,                       int lineType = LINE_8, int shift = 0);

椭圆

CV_EXPORTS_W void ellipse(InputOutputArray img, const RotatedRect& box, const Scalar& color,                        int thickness = 1, int lineType = LINE_8);

CV_EXPORTS_W void ellipse(InputOutputArray img, Point center, Size axes,                        double angle, double startAngle, double endAngle,                        const Scalar& color, int thickness = 1,                        int lineType = LINE_8, int shift = 0);

文字

CV_EXPORTS_W void putText( InputOutputArray img, const String& text, Point org,                         int fontFace, double fontScale, Scalar color,                         int thickness = 1, int lineType = LINE_8,                         bool bottomLeftOrigin = false );

示例

官方示例一

#include #include #include #define w 400using namespace cv;void MyEllipse( Mat img, double angle );void MyFilledCircle( Mat img, Point center );void MyPolygon( Mat img );void MyLine( Mat img, Point start, Point end );int main( void ){    char atom_window[] = "Drawing 1: Atom";    char rook_window[] = "Drawing 2: Rook";    Mat atom_image = Mat::zeros( w, w, CV_8UC3 );    Mat rook_image = Mat::zeros( w, w, CV_8UC3 );    MyEllipse( atom_image, 90 );    MyEllipse( atom_image, 0 );    MyEllipse( atom_image, 45 );    MyEllipse( atom_image, -45 );    MyFilledCircle( atom_image, Point( w/2, w/2) );    MyPolygon( rook_image );    rectangle( rook_image,               Point( 0, 7*w/8 ),               Point( w, w),               Scalar( 0, 255, 255 ),               FILLED,               LINE_8 );    MyLine( rook_image, Point( 0, 15*w/16 ), Point( w, 15*w/16 ) );    MyLine( rook_image, Point( w/4, 7*w/8 ), Point( w/4, w ) );    MyLine( rook_image, Point( w/2, 7*w/8 ), Point( w/2, w ) );    MyLine( rook_image, Point( 3*w/4, 7*w/8 ), Point( 3*w/4, w ) );    imshow( atom_window, atom_image );    moveWindow( atom_window, 0, 200 );    imshow( rook_window, rook_image );    moveWindow( rook_window, w, 200 );    waitKey( 0 );    return(0);}void MyEllipse( Mat img, double angle ){    int thickness = 2;    int lineType = 8;    ellipse( img,             Point( w/2, w/2 ),             Size( w/4, w/16 ),             angle,             0,             360,             Scalar( 255, 0, 0 ),             thickness,             lineType );}void MyFilledCircle( Mat img, Point center ){    circle( img,            center,            w/32,            Scalar( 0, 0, 255 ),            FILLED,            LINE_8 );}void MyPolygon( Mat img ){    int lineType = LINE_8;    Point rook_points[1][20];    rook_points[0][0]  = Point(    w/4,   7*w/8 );    rook_points[0][1]  = Point(  3*w/4,   7*w/8 );    rook_points[0][2]  = Point(  3*w/4,  13*w/16 );    rook_points[0][3]  = Point( 11*w/16, 13*w/16 );    rook_points[0][4]  = Point( 19*w/32,  3*w/8 );    rook_points[0][5]  = Point(  3*w/4,   3*w/8 );    rook_points[0][6]  = Point(  3*w/4,     w/8 );    rook_points[0][7]  = Point( 26*w/40,    w/8 );    rook_points[0][8]  = Point( 26*w/40,    w/4 );    rook_points[0][9]  = Point( 22*w/40,    w/4 );    rook_points[0][10] = Point( 22*w/40,    w/8 );    rook_points[0][11] = Point( 18*w/40,    w/8 );    rook_points[0][12] = Point( 18*w/40,    w/4 );    rook_points[0][13] = Point( 14*w/40,    w/4 );    rook_points[0][14] = Point( 14*w/40,    w/8 );    rook_points[0][15] = Point(    w/4,     w/8 );    rook_points[0][16] = Point(    w/4,   3*w/8 );    rook_points[0][17] = Point( 13*w/32,  3*w/8 );    rook_points[0][18] = Point(  5*w/16, 13*w/16 );    rook_points[0][19] = Point(    w/4,  13*w/16 );    const Point* ppt[1] = { rook_points[0] };    int npt[] = { 20 };    fillPoly( img,              ppt,              npt,              1,              Scalar( 255, 255, 255 ),              lineType );}void MyLine( Mat img, Point start, Point end ){    int thickness = 2;    int lineType = LINE_8;    line( img,          start,          end,          Scalar( 0, 0, 0 ),          thickness,          lineType );}

官方示例二

#include #include #include #include #include using namespace cv;const 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;static 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 );int main( void ){    int c;    char window_name[] = "Drawing_2 Tutorial";    RNG rng( 0xFFFFFFFF );    Mat image = Mat::zeros( window_height, window_width, CV_8UC3 );    imshow( window_name, image );    waitKey( DELAY );    c = Drawing_Random_Lines(image, window_name, rng);    if( c != 0 ) return 0;    c = Drawing_Random_Rectangles(image, window_name, rng);    if( c != 0 ) return 0;    c = Drawing_Random_Ellipses( image, window_name, rng );    if( c != 0 ) return 0;    c = Drawing_Random_Polylines( image, window_name, rng );    if( c != 0 ) return 0;    c = Drawing_Random_Filled_Polygons( image, window_name, rng );    if( c != 0 ) return 0;    c = Drawing_Random_Circles( image, window_name, rng );    if( c != 0 ) return 0;    c = Displaying_Random_Text( image, window_name, rng );    if( c != 0 ) return 0;    c = Displaying_Big_End( image, window_name, rng );    if( c != 0 ) return 0;    waitKey(0);    return 0;}static Scalar randomColor( RNG& rng ){    int icolor = (unsigned) rng;    return Scalar( icolor&255, (icolor>>8)&255, (icolor>>16)&255 );}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;}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;}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;}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;}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;}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;}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;}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;}

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