Discovery and draw the outline of the image

 

 

 

 

 

 

 

 

 

 

#include <opencv2/opencv.hpp>
#include <iostream>
#include <math.h>

using namespace std;
using namespace cv;

Mat src, dst;
const char* output_win = "findcontours-demo";
int threshold_value = 100;
int threshold_max = 255;
RNG rng;
void Demo_Contours(int, void*);
int main(int argc, char** argv) {
    src = imread("L:/12.jpg");
    if (src.empty()) {
        printf("could not load image...\n");
        return -1;
    }
    namedWindow("input-image", CV_WINDOW_AUTOSIZE);
    namedWindow("output_win", CV_WINDOW_AUTOSIZE);
    imshow("input-image", src);
    cvtColor(src, src, CV_BGR2GRAY);

    const char* trackbar_title = "Threshold Value:";
    createTrackbar (trackbar_title, output_win, & threshold_value, threshold_max, Demo_Contours); 
    Demo_Contours ( 0 , 0 ); 

    waitKey ( 0 );
     return  0 ; 
} 

void Demo_Contours ( int , void * ) { 
    Mat canny_output; 
    Vector <Vector <>> Contours Point ;     // defined below using a two-dimensional array array of FIG 
    Vector <Vec4i> hierachy;             // array dimensional integer    
    the Canny (the src, canny_output, threshold_value, threshold_value * 2 , . 3 ,to false );
     // the Canny edge detector, the threshold value 
    findContours (canny_output, Contours, hierachy, RETR_TREE, CHAIN_APPROX_SIMPLE, Point ( 0 , 0 ));
     // findContours Parameters:
     // 1. 2. The input image is detected by all the contour of the object ( array) 3. 4. contour topology discovery methods 6. The default mode P (0,0) is not displaced 
    dst = Mat :: zeros (src.size (), CV_8UC3);   // initialize src dst is a size zero matrix of 

    the RNG RNG ( 12345 );
     for (size_t I = 0 ; I <contours.size (); I ++ ) { 
        the Scalar Color = the Scalar (rng.uniform ( 0 , 255 ), rng.uniform ( 0 , 255), Rng.uniform ( 0 , 255 ));
         // for each segment of the outline contours take a random color 
        drawContours (DST, contours, I, Color, . 1 , . 8 , hierachy, 0 , Point ( 0 , 0 ));
         / / drawContours parameters:
         // 1. 2. contour output image of contours 3. 4. several contour line type color 5. 6. 7. width topology 
         // 8.0 1 represents a drawing showing the current drawing and the current 9. the displacement profile contour embedded 

    } 
    imshow (output_win, DST); 
}

result:

 

 

 

 

 Code involves the use of an array of methods:

 

  vector <vector <Point >> contours; // define a two-dimensional array using the array shown in the graph 
    vector <Vec4i> hierachy; four-dimensional array of integers //   

 

The two arrays of  findContours the second and third parameters;

vector <vector <Point >>: // Find and general profile contouring using parameter contours

vector vessel which put a vector container, put some sub-container

 

 

 vector <V ec 4 i>: put a 4-dimensional vector // int drawn generally used to find the contour and profile parameters hierarchy

 

 

 vector <R e ct>: width * height from the pixel position (x * y)

 

 

 vector <R otated R ec t>: FIG three members