1.目的
（1）使用openCV函數minAreaRect獲取矩形邊界
（2）使用openCV函數fitEllipse獲取橢圓邊界
2.完整代碼
（1）CommonInclude.h
#ifndef COMMON_INCLUDE
#define COMMON_INCLUDE
#include<iostream>
#include<opencv2/core/core.hpp>
#include<opencv2/highgui/highgui.hpp>
#include<opencv2/imgproc/imgproc.hpp>
using namespace std;
using namespace cv;
#endif（2）Bounding.cpp
#include"CommonInclude.h"
Mat src; Mat src_gray;
int thresh = 100;
int max_thresh = 255;
RNG rng(12345);
/** @function thresh_callback */
void thresh_callback(int, void* )
{
Mat threshold_output;
vector<vector<Point> > contours;
vector<Vec4i> hierarchy;
/// 閾值化檢測邊界
threshold( src_gray, threshold_output, thresh, 255, THRESH_BINARY );
/// 尋找輪廓
findContours( threshold_output, contours, hierarchy, CV_RETR_TREE, CV_CHAIN_APPROX_SIMPLE, Point(0, 0) );
/// 對每個找到的輪廓創建可傾斜的邊界框和橢圓
vector<RotatedRect> minRect( contours.size() );
vector<RotatedRect> minEllipse( contours.size() );
for( int i = 0; i < contours.size(); i++ )
{
//返回輪廓的矩形邊界框
minRect[i] = minAreaRect( Mat(contours[i]) );
if( contours[i].size() > 5 )
{
//返回輪廓的橢圓邊界框
minEllipse[i] = fitEllipse( Mat(contours[i]) );
}
}
/// 繪出輪廓及其可傾斜的邊界框和邊界橢圓
Mat drawing = Mat::zeros( threshold_output.size(), CV_8UC3 );
for( int i = 0; i< contours.size(); i++ )
{
Scalar color = Scalar( rng.uniform(0, 255), rng.uniform(0,255), rng.uniform(0,255) );
// contour
drawContours( drawing, contours, i, color, 1, 8, vector<Vec4i>(), 0, Point() );
// ellipse
ellipse( drawing, minEllipse[i], color, 2, 8 );
// 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 );
}
/// 結果在窗體中顯示
namedWindow( "Contours", CV_WINDOW_AUTOSIZE );
imshow( "Contours", drawing );
}
/** @function main */
int main( int argc, char** argv )
{
/// 加載源圖像
src = imread( argv[1], 1 );
/// 轉爲灰度圖並模糊化
cvtColor( src, src_gray, CV_BGR2GRAY );
blur( src_gray, src_gray, Size(3,3) );
/// 創建窗體
char source_window[] = "Source";
namedWindow( source_window, CV_WINDOW_AUTOSIZE );
imshow( source_window, src );
createTrackbar( " Threshold:", "Source", &thresh, max_thresh, thresh_callback );
thresh_callback( 0, 0 );
waitKey(0);
return(0);
}