opencv-随机生成器和文本操作

本文主要用opencv2.4.3随机函数实现生成线条，矩形，椭圆，折线，填充多边形，以及在运行窗口中显示文本的功能。

#include 
#include 
#include 
#include 

using namespace cv;

//全局变量
const int NUMBER = 100;
const int DELAY = 5; //静态变量

const int window_width = 900;
const int window_height = 600;//静态变量

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;

//函数头声明
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 );


/**
 * @function main
 */
int main( int argc, char** argv )
{
  int c;

  //创建一个窗口
  char window_name[] = "Drawing_2 Tutorial";

  //创建一个随机对象rng
  RNG rng( 0xFFFFFFFF );

  //用零初始化矩阵，即窗口背景为黑色
  Mat image = Mat::zeros( window_height, window_width, CV_8UC3 );
  //在窗口显示并延时
  imshow( window_name, image );
  waitKey( DELAY );
  
  //===开始画图===
  //先画一些线条
  c = Drawing_Random_Lines(image, window_name, rng);
  if( c != 0 ) return 0;

  //再画一个矩形
  c = Drawing_Random_Rectangles(image, window_name, rng);
  if( c != 0 ) return 0;

  //画一些椭圆
  c = Drawing_Random_Ellipses( image, window_name, rng );
  if( c != 0 ) return 0;

  //现在画一些折线
  c = Drawing_Random_Polylines( image, window_name, rng );
  if( c != 0 ) return 0;

  //画填充多边形
  c = Drawing_Random_Filled_Polygons( image, window_name, rng );
  if( c != 0 ) return 0;

  //画圆
  c = Drawing_Random_Circles( image, window_name, rng );
  if( c != 0 ) return 0;

  //在随机位置显示文本
  c = Displaying_Random_Text( image, window_name, rng );
  if( c != 0 ) return 0;

  //显示结束
  c = Displaying_Big_End( image, window_name, rng );
  if( c != 0 ) return 0;

  waitKey(0);
  return 0;
}

//函数定义

/**
 * @function randomColor
 * @brief Produces a random color given a random object
 */
static Scalar randomColor( RNG& rng )
{
  int icolor = (unsigned) rng;
  //Scalar函数里面的三个参数对应R,G,B
  return Scalar( icolor&255, (icolor>>8)&255, (icolor>>16)&255 );
}


/**
 * @function Drawing_Random_Lines
 */
int Drawing_Random_Lines( Mat image, char* window_name, RNG rng )
{
  int lineType = 8;
  Point pt1, pt2;

  for( int i = 0; i < NUMBER; i++ )
  {
	//rng.unifor(a,b)在即在闭区间[a,b]内随机分配一个数值
    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 );

	//randomColor(rng)随机为rng分配一种颜色
    line( image, pt1, pt2, randomColor(rng), rng.uniform(1, 10), 8 );
    
	imshow( window_name, image );
    
	//延时等待循环
	if( waitKey( DELAY ) >= 0 )
      { return -1; }
  }

  return 0;
}

/**
 * @function Drawing_Rectangles
 */
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 Drawing_Random_Ellipses
 */
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 Drawing_Random_Polylines
 */
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 Drawing_Random_Filled_Polygons
 */
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 Drawing_Random_Circles
 */
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 Displaying_Random_Text
 */
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);

	//把"Testing text rendering"放在图片上，文本的左下角确定在点org,
	//字体大小在[0,8]整数范围随机分配，可扩展范围[0.1,5,1]
	//文本颜色随机分配，文字厚度在[1,10]随机分配，可扩展范围[1,10].
    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;
}

/**
 * @function Displaying_Big_End
 */
int Displaying_Big_End( Mat image, char* window_name, RNG rng )
{
  //getTextSize函数获得文本参数的大小
  Size textsize = getTextSize("OpenCV forever!", CV_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 )
  {
    //imge2为原始图像和Scalar::all(i)对应像素点的差值，常用语饱和操作的中间变量
    image2 = image - Scalar::all(i);
    putText( image2, "OpenCV forever!", org, CV_FONT_HERSHEY_COMPLEX, 3,
             Scalar(i, i, 255), 5, lineType );

    imshow( window_name, image2 );
    if( waitKey(DELAY) >= 0 )
       { return -1; }
  }

  return 0;
}