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/**
* @function generalContours_demo1.cpp
* @brief Demo code to find contours in an image
* @author OpenCV team
*/
#include "opencv2/imgcodecs.hpp"
#include "opencv2/highgui.hpp"
#include "opencv2/imgproc.hpp"
#include <iostream>
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 argc, char** argv )
{
//![setup]
/// Load source image
CommandLineParser parser( argc, argv, "{@input | ../data/stuff.jpg | input image}" );
src = imread( parser.get<String>( "@input" ), IMREAD_COLOR );
if( src.empty() )
{
cout << "Could not open or find the image!\n" << endl;
cout << "usage: " << argv[0] << " <Input image>" << endl;
return -1;
}
/// Convert image to gray and blur it
cvtColor( src, src_gray, COLOR_BGR2GRAY );
blur( src_gray, src_gray, Size(3,3) );
//![setup]
//![createWindow]
/// Create Window
const char* source_window = "Source";
namedWindow( source_window, WINDOW_AUTOSIZE );
imshow( source_window, src );
//![createWindow]
//![taskbar]
createTrackbar( " Threshold:", "Source", &thresh, max_thresh, thresh_callback );
//![taskbar]
//![callback00]
thresh_callback( 0, 0 );
//![callback00]
//![waitForIt]
waitKey(0);
//![waitForIt]
return(0);
}
/**
* @function thresh_callback
*/
void thresh_callback(int, void* )
{
Mat threshold_output;
vector<vector<Point> > contours;
vector<Vec4i> hierarchy;
//![threshold]
/// Detect edges using Threshold
threshold( src_gray, threshold_output, thresh, 255, THRESH_BINARY );
//![threshold]
//![findContours]
/// Find contours
findContours( threshold_output, contours, hierarchy, RETR_TREE, CHAIN_APPROX_SIMPLE, Point(0, 0) );
//![findContours]
/// 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() );
//![allthework]
for( size_t i = 0; i < contours.size(); i++ )
{
approxPolyDP( contours[i], contours_poly[i], 3, true );
boundRect[i] = boundingRect( contours_poly[i] );
minEnclosingCircle( contours_poly[i], center[i], radius[i] );
}
//![allthework]
//![zeroMat]
/// Draw polygonal contour + bonding rects + circles
Mat drawing = Mat::zeros( threshold_output.size(), CV_8UC3 );
//![zeroMat]
//![forContour]
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 );
}
//![forContour]
//![showDrawings]
/// Show in a window
namedWindow( "Contours", WINDOW_AUTOSIZE );
imshow( "Contours", drawing );
//![showDrawings]
}