OpenCV closing a shape and filling it

I want to output a blue-filled hand but get the incorrect output. I've included the input picture, incorrect output picture and code below. i think the code below does not fill the whole image because the image isn't closed yet at the right boundary. how do i close the shape and fill it with blue properly? ``` #include <opencv2/core/core.hpp> #include <opencv2/highgui/highgui.hpp> #include <opencv2/imgproc/imgproc.hpp> #include <iostream> #include <stdio.h> #include <stdlib.h> using namespace cv; using namespace std; void drawStuff(); void showInputWindow(); void showCannyWindow(); void showContourWindow(); int thresh = 40; int max_thresh = 120; Mat img_rgb,img_gray,img_bw,canny_output,drawing; int main(){ img_rgb = imread("qq.jpg"); blur( img_rgb, img_rgb, Size(3,3) ); cvtColor(img_rgb,img_gray,CV_RGB2GRAY); showInputWindow(); drawStuff(); cv::waitKey(0); } void drawStuff(){ vector<vector<Point> > contours; vector<Vec4i> hierarchy; Canny( img_gray, canny_output, thresh, thresh*2, 3 ); cv::dilate(canny_output, canny_output, cv::Mat(), cv::Point(-1,-1)); showCannyWindow(); findContours( canny_output, contours, hierarchy, CV_RETR_TREE, CV_CHAIN_APPROX_SIMPLE, Point(0, 0) ); drawing = Mat::zeros( canny_output.size(), CV_8UC3 ); vector<Point> approxShape; for(size_t i = 0; i < contours.size(); i++){ approxPolyDP(contours[i], approxShape, arcLength(Mat(contours[i]), true)*0.04, true); drawContours(drawing, contours, i, Scalar(255, 0, 0), CV_FILLED); // fill BLUE } showContourWindow(); } void showInputWindow(){ cv::namedWindow("InputImage"); cv::imshow("InputImage",img_rgb); } void showCannyWindow(){ cv::namedWindow("Canny"); cv::imshow("Canny",canny_output); } void showContourWindow(){ cv::namedWindow("Fill"); cv::imshow("Fill",drawing); } ```