Question

我想拍摄一段视频并将其显示在一个窗口上，并有第二个窗口，其中轮廓同时显示。我正在努力解决如何在第二个窗口中显示已处理视频的问题。请分析我的代码并建议解决方案或指出出错的地方可能会给我一些在线教程或来源的指示。感谢。

     #include "iostream"
    #include<opencv\cv.h>
    #include<opencv\highgui.h>
    #include<opencv\ml.h>
    #include<opencv\cxcore.h>
    #include <iostream> 
    #include <vector>
    #include <string> 
    #include <opencv2/core/core.hpp> // Basic OpenCV structures (cv::Mat)
    #include <opencv2/highgui/highgui.hpp> // Video write

    using namespace cv;
    using namespace std;


    Mat image; Mat image_gray; Mat image_gray2; Mat threshold_output;
    Mat frame;
    int thresh=100, max_thresh=255;


    int main(int argc, char** argv) {

     //Capture Video
     VideoCapture capCam(1);
     if (!capCam.isOpened()){
        cout<<"ERROR: Failed to Initialize Camera"<<endl;
        return 1;
     }
     else{
        cout<<"Camera Initialized"<<endl;
     }

 //Create Window
char* ImputFootage = "Source";
namedWindow(ImputFootage, CV_WINDOW_AUTOSIZE);
imshow(ImputFootage, frame);

char* OutputFootage = "Processed";
namedWindow(OutputFootage, CV_WINDOW_AUTOSIZE);
imshow(OutputFootage, frame);



 while(1){
    capCam>> frame;
    imshow("Source", frame);
    return(1);

    if(capCam.read(ImputFootage)){

        //Convert Image to gray & blur it
cvtColor( image, 
    image_gray, 
    CV_BGR2GRAY );

blur( image_gray, 
    image_gray2,
    Size(3,3) );
//Threshold Gray&Blur Image
threshold(image_gray2, 
    threshold_output, 
    thresh, 
    max_thresh, 
    THRESH_BINARY);

//2D Container
vector<vector<Point>> contours;

//Fnd Countours Points, (Imput Image, Storage, Mode1, Mode2, Offset??)
findContours(threshold_output,
    contours, // a vector of contours
    CV_RETR_EXTERNAL,// retrieve the external contours
    CV_CHAIN_APPROX_NONE,
    Point(0, 0)); // all pixels of each contours    

// Draw black contours on a white image
Mat result(threshold_output.size(),CV_8U,Scalar(255));
drawContours(result,contours,
    -1, // draw all contours
    Scalar(0), // in black
    2); // with a thickness of 2


    }
 }
char CheckForEscKey = waitKey(10);
return 1;
}

Answer 1

您应在致电imshow("Processed", result);

后致电drawContours

Answer 2

你试图在用相机拍摄之前显示帧。编译器没有给你错误，因为Mat被声明了，但它们没有值（null），而且你试图显示Mat图像，但你从相机捕获的是Mat帧。此外，你没有退出（esc序列，你的等待键是相机循环OUT。

无论如何，这是你的代码（重写），我希望这是你想要的。

#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <opencv2/imgproc/imgproc.hpp>

#include <cstdio>
#include <iostream>
#include <stdlib.h>
#include <stdio.h>

using namespace std;
using namespace cv;

Mat image;
Mat image_gray;
Mat image_gray2;
Mat threshold_output;
Mat frame;
int thresh = 100, max_thresh = 255;

int main(int argc, char** argv)
{

    //Capture Video
    VideoCapture capCam(0);
    if (!capCam.isOpened())
    {
        cout << "ERROR: Failed to Initialize Camera" << endl;
        return 1;
    }
    else
    {
        cout << "Camera Initialized" << endl;
    }

    //Create Window
    char* ImputFootage = "Source";
    namedWindow(ImputFootage, CV_WINDOW_AUTOSIZE);

    char* OutputFootage = "Processed";
    namedWindow(OutputFootage, CV_WINDOW_AUTOSIZE);

    while (1)
    {
        capCam >> frame;
        imshow(ImputFootage, frame);

        if (capCam.read(frame))
        {

            //Convert Image to gray & blur it
            cvtColor(frame, image_gray, CV_BGR2GRAY);

            blur(image_gray, image_gray2, Size(3, 3));
            //Threshold Gray&Blur Image
            threshold(image_gray2, threshold_output, thresh, max_thresh, THRESH_BINARY);

            //2D Container
            vector<vector<Point> > contours;

            //Fnd Countours Points, (Imput Image, Storage, Mode1, Mode2, Offset??)
            findContours(threshold_output, contours, // a vector of contours
                    CV_RETR_EXTERNAL, // retrieve the external contours
                    CV_CHAIN_APPROX_NONE, Point(0, 0)); // all pixels of each contours

            // Draw black contours on a white image
            Mat result(threshold_output.size(), CV_8U, Scalar(255));
            drawContours(result, contours, -1, // draw all contours
                    Scalar(0), // in black
                    2); // with a thickness of 2

            imshow(OutputFootage, result);

            char CheckForEscKey = waitKey(10);

            //If the key pressed by user is Esc(ASCII is 27) then break out of the loop
            if (CheckForEscKey == 27)
            {
                break;
            }

        }
    }

    return 0;
}

OpenCV：在一个窗口中录制素材并在第二个窗口中显示相同的视频但仅包含轮廓

2 个答案: