【opencv練習35 - 輪廓旋轉邊界框 + 橢圓】

/*******************************************************
    測試程序【輪廓的 旋轉邊界框 + 橢圓】
    時間：2016年9月3日
********************************************************/

Mat src; Mat src_gray;
int thresh = 100;
int max_thresh = 255;
RNG rng(12345);

void thresh_callback(int, void* );

int main(void)
{
  src = imread("Image.jpg", 1 );

  cvtColor( src, src_gray, COLOR_BGR2GRAY );
  blur( src_gray, src_gray, Size(3,3) );

  const char* source_window = "Source";
  namedWindow( source_window, WINDOW_AUTOSIZE );
  imshow( source_window, src );

  createTrackbar( " Threshold:", "Source", &thresh, max_thresh, thresh_callback );
  thresh_callback( 0, 0 );

  waitKey(0);
  return(0);
}

void thresh_callback(int, void* )
{
  Mat threshold_output;
  vector<vector<Point> > contours;      //【輪廓】點的數組 的數組(二維數組)
  vector<Vec4i> hierarchy;              

  //【1、閾值 + find輪廓】
  threshold( src_gray, threshold_output, thresh, 255, THRESH_BINARY );
  //【threshold_output——>contours】
  findContours( threshold_output, contours, hierarchy, CV_RETR_TREE, CV_CHAIN_APPROX_SIMPLE, Point(0, 0) );

  //【2、查找每個輪廓的 旋轉矩形，橢圓】 
  vector<RotatedRect> minRect( contours.size() );
  vector<RotatedRect> minEllipse( contours.size() );

  for( size_t i = 0; i < contours.size(); i++ )
     { 
        minRect[i] = minAreaRect( Mat(contours[i]) );   //【contours ————> minRect】      
       if( contours[i].size() > 5 )                     //  contours點數 > 5
         { 
            minEllipse[i] = fitEllipse( Mat(contours[i]) );//【contours ————> minEllipse】
        }
     }

  //【3、繪製】
  Mat drawing = Mat::zeros( threshold_output.size(), CV_8UC3 );
  for( size_t i = 0; i< contours.size(); i++ )
     {
        // 隨機色彩
       Scalar color = Scalar( rng.uniform(0, 255), rng.uniform(0,255), rng.uniform(0,255) );
       //【輪廓】contour
       drawContours( drawing, contours, (int)i, color, 1, 8, vector<Vec4i>(), 0, Point() );
       //【橢圓】 ellipse
       ellipse( drawing, minEllipse[i], color, 2, 8 );
       //【旋轉矩形】rotated rectangle
       Point2f rect_points[4]; 
       minRect[i].points( rect_points );

       for( int j = 0; j < 4; j++ )
          line( drawing, rect_points[j], rect_points[(j+1)%4], color, 1, 8 );
     }

  namedWindow( "Contours", WINDOW_AUTOSIZE );
  imshow( "Contours", drawing );
}

![這裏寫圖片描述](http://img.blog.csdn.net/20160909082508142)