OpenCV关闭一个形状并填充它 [英] OpenCV closing a shape and filling it

问题描述

我想输出一个蓝色的手，但得到不正确的输出。我在下面包含了输入图片，错误的输出图片和代码。

我认为下面的代码不会填充整个图片，因为图片尚未关闭

 ＃ 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> >轮廓; 
 vector< Vec4i>层次; 
 
 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  approxPolyDP（contoururs [i]，approxShape，arcLength（Mat（contoururs [i]），true）* 0.04 ，true）; 
 drawContours（drawing，contoururs，i，Scalar（255，0，0），CV_FILLED）; // fill BLUE 
} 
 
 showContourWindow（）; 
} 
 
 void showInputWindow（）{
 cv :: namedWindow（InputImage）; 
 cv :: imshow（InputImage，img_rgb）; 
} 
 
 void displayCannyWindow（）{
 cv :: namedWindow（Canny）; 
 cv :: imshow（Canny，canny_output）; 
} 
 void showContourWindow（）{
 cv :: namedWindow（Fill）; 
 cv :: imshow（Fill，drawing）; 
} 
  

解决方案

要解决您的问题，应该只检测外轮廓。通过这样做，你将只得到一个轮廓，你可以感觉到它的颜色。

  findContours（canny_output，contour，hierarchy，Imgproc.RETR_EXTERNAL，CV_CHAIN_APPROX_SIMPLE，Point（0，0））; 
  

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);
}

解决方案

To solve your problem, you should detect only outer contours. By doing that you will get only one contour, and you can feel it with the color.

findContours( canny_output, contours, hierarchy, Imgproc.RETR_EXTERNAL, CV_CHAIN_APPROX_SIMPLE, Point(0, 0) );

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