Getting more than a one pixel value in a single contour - c++

Question

Hello after connected component labeling for a single label why am I getting more than a one pixel value ?
this is my image
#include <iostream>
#include <vector>
#include <opencv2/highgui/highgui.hpp>
#include <opencv2/imgproc/imgproc.hpp>
using namespace cv;
using namespace std;
void FindBlobs(const cv::Mat &binary, std::vector < std::vector<cv::Point2i> > &blobs);
int main(int argc, char **argv)
{
cv::Mat img = cv::imread("/Users/Rodrane/Documents/XCODE/test/makalesvm/persembe.png", 0); if(!img.data) {
std::cout << "File not found" << std::endl;
return -1;
}
cv::namedWindow("binary");
cv::namedWindow("labelled");
cv::Mat output = cv::Mat::zeros(img.size(), CV_8UC3);
cv::Mat binary;
std::vector < std::vector<cv::Point2i > > blobs;
equalizeHist( img , img );
cv::threshold(img, binary, 0, 1, cv::THRESH_BINARY_INV);
FindBlobs(binary, blobs);
// Randomy color the blobs
for(size_t i=0; i < blobs.size(); i++) {
unsigned char r = 255 * (rand()/(1.0 + RAND_MAX));
unsigned char g = 255 * (rand()/(1.0 + RAND_MAX));
unsigned char b = 255 * (rand()/(1.0 + RAND_MAX));
for(size_t j=0; j < blobs[i].size(); j++) {
int x = blobs[i][j].x;
int y = blobs[i][j].y;
output.at<cv::Vec3b>(y,x)[0] = b;
output.at<cv::Vec3b>(y,x)[1] = g;
output.at<cv::Vec3b>(y,x)[2] = r;
}
}
cout << "H = "<< endl << " " << output << endl << endl;
cv::imshow("binary", img);
cv::imshow("labelled", output);
cv::waitKey(0);
return 0;
}
void FindBlobs(const cv::Mat &binary, std::vector < std::vector<cv::Point2i> > &blobs)
{
blobs.clear();
// Fill the label_image with the blobs
// 0 - background
// 1 - unlabelled foreground
// 2+ - labelled foreground
cv::Mat label_image;
binary.convertTo(label_image, CV_32SC1);
int label_count = 2; // starts at 2 because 0,1 are used already
for(int y=0; y < label_image.rows; y++) {
int *row = (int*)label_image.ptr(y);
for(int x=0; x < label_image.cols; x++) {
if(row[x] != 1) {
continue;
}
cv::Rect rect;
cv::floodFill(label_image, cv::Point(x,y), label_count, &rect, 0, 0, 4);
std::vector <cv::Point2i> blob;
for(int i=rect.y; i < (rect.y+rect.height); i++) {
int *row2 = (int*)label_image.ptr(i);
for(int j=rect.x; j < (rect.x+rect.width); j++) {
if(row2[j] != label_count) {
continue;
}
blob.push_back(cv::Point2i(j,i));
}
}
blobs.push_back(blob);
label_count++;
}
}
}
actually this is a single label when I print the image
however when I check pixel values. I see there is actually 2 different values (I just write down part of the matrix not all)
H = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 192, 33, 0, 192, 33, 0, 192, 33, 0, 0, 0, 0, ]
also by adding this line of code to the last line of FindBlobs function I recieve 3 since the label_count variable starts from 2 this also proves that H is a single label.
cout << "number of labels = "<< endl << " " << label_count << endl << endl;