how to get bounding rectangle on both source and contour window? - opencv

Question

I am using this link to get bound rectangle for contour
I want to know how can I get the same rectangle on source window, which is detected in the contour window.
Thank you very much in advance.

Answer 1

Create your polygons and circles in main( int argc, char** argv ) function.
namedWindow( source_window, CV_WINDOW_AUTOSIZE );
imshow( source_window, drawing );
3.Comment
createTrackbar( " Threshold:", "Source", &thresh, max_thresh, thresh_callback );
thresh_callback( 0, 0 );

Answer 2

Answered here. Code by sturkmen:
/**
* #function generalContours_demo1.cpp
* #brief Demo code to find contours in an image
* #author OpenCV team
*/
#include "opencv2/highgui/highgui.hpp"
#include "opencv2/imgproc/imgproc.hpp"
#include <iostream>
#include <stdio.h>
#include <stdlib.h>
using namespace cv;
using namespace std;
Mat src; Mat src_gray;
int thresh = 100;
int max_thresh = 255;
RNG rng(12345);
/// Function header
void thresh_callback(int, void* );
/**
* #function main
*/
int main( int, char** argv )
{
/// Load source image and convert it to gray
src = imread( argv[1], 1 );
/// Convert image to gray and blur it
cvtColor( src, src_gray, COLOR_BGR2GRAY );
blur( src_gray, src_gray, Size(3,3) );
/// Create Window
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);
}
/**
* #function thresh_callback
*/
void thresh_callback(int, void* )
{
Mat threshold_output;
vector<vector<Point> > contours;
vector<Vec4i> hierarchy;
/// Detect edges using Threshold
threshold( src_gray, threshold_output, thresh, 255, THRESH_BINARY );
/// Find contours
findContours( threshold_output, contours, hierarchy, CV_RETR_TREE, CV_CHAIN_APPROX_SIMPLE, Point(0, 0) );
/// Approximate contours to polygons + get bounding rects and circles
vector<vector<Point> > contours_poly( contours.size() );
vector<Rect> boundRect( contours.size() );
vector<Point2f>center( contours.size() );
vector<float>radius( contours.size() );
for( size_t i = 0; i < contours.size(); i++ )
{ approxPolyDP( Mat(contours[i]), contours_poly[i], 3, true );
boundRect[i] = boundingRect( Mat(contours_poly[i]) );
minEnclosingCircle( contours_poly[i], center[i], radius[i] );
}
/// Draw polygonal contour + bonding rects + circles
Mat src2 = src.clone(); //add this line
Mat drawing = Mat::zeros( threshold_output.size(), CV_8UC3 );
for( size_t i = 0; i< contours.size(); i++ )
{
Scalar color = Scalar( rng.uniform(0, 255), rng.uniform(0,255), rng.uniform(0,255) );
drawContours( drawing, contours_poly, (int)i, color, 1, 8, vector<Vec4i>(), 0, Point() );
rectangle( drawing, boundRect[i].tl(), boundRect[i].br(), color, 2, 8, 0 );
circle( drawing, center[i], (int)radius[i], color, 2, 8, 0 );
drawContours( src2, contours_poly, (int)i, color, 1, 8, vector<Vec4i>(), 0, Point() );//add this line
rectangle( src2, boundRect[i].tl(), boundRect[i].br(), color, 2, 8, 0 );//add this line
circle( src2, center[i], (int)radius[i], color, 2, 8, 0 );//add this line
}
/// Show in a window
namedWindow( "Contours", WINDOW_AUTOSIZE );
imshow( "Contours", drawing );
imshow( "Source", src2 );//add this line
}