c++ - 无法使用网络摄像头运行 c++ 项目，但它实际上可以使用图像

Question

我创建了名为“文档扫描仪”的 c++ 项目。使用图像，他可以完美地工作，但是使用我的网络摄像头时，他给了我一个错误“矢量下标超出范围”。

图像代码：

#include <opencv2/imgcodecs.hpp>
#include <opencv2/highgui.hpp>
#include <opencv2/imgproc.hpp>
#include <iostream>

using namespace cv;
using namespace std;


//////////////// Project 2 – Document Scanner ////////////

Mat imgOriginal, imgGray, imgCanny, imgThre, imgBlur, imgDil, imgErode, imgCrop, imgWarp;
vector<Point> initialPoints, docPoints;

float w = 420, h = 596; //dimensions of a4 paper multiplied by 2 

Mat preProcessing(Mat img) {
    
    cvtColor(img, imgGray, COLOR_BGR2GRAY);
    GaussianBlur(imgGray, imgBlur, Size(3, 3), 3, 0);
    Canny(imgBlur, imgCanny, 25, 75);

    Mat kernel = getStructuringElement(MORPH_RECT, Size(3, 3));
    dilate(imgCanny, imgDil, kernel);
    //erode(imgDil, imgErode, kernel);
    return imgDil;
}

vector<Point> getContours(Mat image) {



    vector<vector<Point>> contours;
    vector<Vec4i> hierarchy;

    findContours(imgDil, contours, hierarchy, RETR_EXTERNAL, CHAIN_APPROX_SIMPLE);
    //drawContours(img, contours, -1, Scalar(255, 0, 255), 2);

    vector<vector<Point>> conPoly(contours.size());
    vector<Rect> boundRect(contours.size());

    vector<Point> biggest;
    int maxArea = 0;

    for (int i = 0; i < contours.size(); i++)
    {
        int area = contourArea(contours[i]);
        cout << area << endl;


        string objectType;

        if (area > 1000) {

            float peri = arcLength(contours[i], true);
            approxPolyDP(contours[i], conPoly[i], 0.02 * peri, true);

            if (area > maxArea && conPoly[i].size() == 4) {
                
                //drawContours(imgOriginal, conPoly, i, Scalar(255, 0, 255), 5);
                biggest = { conPoly[i][0],conPoly[i][1], conPoly[i][2], conPoly[i][3] };
                maxArea = area;

            }

            //drawContours(imgOriginal, conPoly, i, Scalar(255, 0, 255), 2);
            //rectangle(imgOriginal, boundRect[i].tl(), boundRect[i].br(), Scalar(0, 255, 0), 5);
        }
    }
    return biggest;
}

void drawPoints(vector<Point> points, Scalar color) {

    for (int i = 0; i < points.size(); i++) {

        circle(imgOriginal, points[i], 10, color, FILLED);
        putText(imgOriginal, to_string(i), points[i], FONT_HERSHEY_PLAIN, 4, color, 4);
    }
}


vector<Point> reorder(vector<Point> points) {
    vector<Point> newPoints;
    vector<int> sumPoints, subPoints;

    for (int i = 0; i < 4; i++) {
        
        sumPoints.push_back(points[i].x + points[i].y);
        subPoints.push_back(points[i].x - points[i].y);
    }

    newPoints.push_back(points[min_element(sumPoints.begin(), sumPoints.end()) - sumPoints.begin()]); //0
    newPoints.push_back(points[max_element(subPoints.begin(), subPoints.end()) - subPoints.begin()]); //1
    newPoints.push_back(points[min_element(subPoints.begin(), subPoints.end()) - subPoints.begin()]); //2
    newPoints.push_back(points[max_element(sumPoints.begin(), sumPoints.end()) - sumPoints.begin()]); //3

    return newPoints;
}

Mat getWarp(Mat img, vector<Point> points, float w, float h) {

    Point2f src[4] = { points[0], points[1], points[2], points[3] };
    Point2f dst[4] = { {0.0f,0.0f}, {w,0.0f}, {0.0f,h}, {w, h} };

    Mat matrix = getPerspectiveTransform(src, dst);
    warpPerspective(img, imgWarp, matrix, Point(w, h));

    return imgWarp;
}


void main() {

    string path = "Resources/paper.jpg";
    imgOriginal = imread(path);
    //resize(imgOriginal, imgOriginal, Size(), 0.5, 0.4);

    // Preprocessing
    imgThre = preProcessing(imgOriginal);
    
    // Get Contours - Biggest 
    initialPoints = getContours(imgThre);
    
    ///drawPoints(initialPoints, Scalar(0,0,255));
    docPoints = reorder(initialPoints);
    //drawPoints(docPoints, Scalar(0, 255, 0));
    
    // Warp
    imgWarp = getWarp(imgOriginal, docPoints, w, h);

    //Crop
    int cropVal = 5;
    Rect roi(cropVal, cropVal, w - (2 * cropVal), h - (2 * cropVal));
    imgCrop = imgWarp(roi);

    imshow("Image", imgOriginal);
    imshow("Image Dilation", imgThre);
    imshow("Image Warp", imgWarp);
    imshow("Image Crop", imgCrop);
    waitKey(0);
}

网络摄像头代码：

#include <opencv2/imgcodecs.hpp>
#include <opencv2/highgui.hpp>
#include <opencv2/imgproc.hpp>
#include <iostream>

using namespace cv;
using namespace std;


//////////////// Project 2 – Document Scanner ////////////

Mat img, imgGray, imgCanny, imgThre, imgBlur, imgDil, imgErode, imgCrop, imgWarp;
vector<Point> initialPoints, docPoints;

float w = 420, h = 596; //dimensions of a4 paper multiplied by 2 

Mat preProcessing(Mat img) {

    cvtColor(img, imgGray, COLOR_BGR2GRAY);
    GaussianBlur(imgGray, imgBlur, Size(3, 3), 3, 0);
    Canny(imgBlur, imgCanny, 25, 75);

    Mat kernel = getStructuringElement(MORPH_RECT, Size(3, 3));
    dilate(imgCanny, imgDil, kernel);
    //erode(imgDil, imgErode, kernel);
    return imgDil;
}

vector<Point> getContours(Mat image) {



    vector<vector<Point>> contours;
    vector<Vec4i> hierarchy;

    findContours(image, contours, hierarchy, RETR_EXTERNAL, CHAIN_APPROX_SIMPLE);
    //drawContours(img, contours, -1, Scalar(255, 0, 255), 2);

    vector<vector<Point>> conPoly(contours.size());
    vector<Rect> boundRect(contours.size());

    vector<Point> biggest;
    int maxArea = 0;

    for (int i = 0; i < contours.size(); i++)
    {
        int area = contourArea(contours[i]);
        cout << area << endl;



        if (area > 1000) {

            float peri = arcLength(contours[i], true);
            approxPolyDP(contours[i], conPoly[i], 0.02 * peri, true);

            if (area > maxArea && conPoly[i].size() == 4) {

                //drawContours(imgOriginal, conPoly, i, Scalar(255, 0, 255), 5);
                biggest = { conPoly[i][0],conPoly[i][1], conPoly[i][2], conPoly[i][3] };
                maxArea = area;

            }

            //drawContours(imgOriginal, conPoly, i, Scalar(255, 0, 255), 2);
            //rectangle(imgOriginal, boundRect[i].tl(), boundRect[i].br(), Scalar(0, 255, 0), 5);
        }
    }
    return biggest;
}

void drawPoints(vector<Point> points, Scalar color) {

    for (int i = 0; i < points.size(); i++) {

        circle(img, points[i], 10, color, FILLED);
        putText(img, to_string(i), points[i], FONT_HERSHEY_PLAIN, 4, color, 4);
    }
}


vector<Point> reorder(vector<Point> points) {
    vector<Point> newPoints;
    vector<int> sumPoints, subPoints;

    for (int i = 0; i < 4; i++) {

        sumPoints.push_back(points[i].x + points[i].y);
        subPoints.push_back(points[i].x - points[i].y);
    }

    newPoints.push_back(points[min_element(sumPoints.begin(), sumPoints.end()) - sumPoints.begin()]); //0
    newPoints.push_back(points[max_element(subPoints.begin(), subPoints.end()) - subPoints.begin()]); //1
    newPoints.push_back(points[min_element(subPoints.begin(), subPoints.end()) - subPoints.begin()]); //2
    newPoints.push_back(points[max_element(sumPoints.begin(), sumPoints.end()) - sumPoints.begin()]); //3

    return newPoints;
}

Mat getWarp(Mat img, vector<Point> points, float w, float h) {

    Point2f src[4] = { points[0], points[1], points[2], points[3] };
    Point2f dst[4] = { {0.0f,0.0f}, {w,0.0f}, {0.0f,h}, {w, h} };

    Mat matrix = getPerspectiveTransform(src, dst);
    warpPerspective(img, imgWarp, matrix, Point(w, h));

    return imgWarp;
}


void main() {
    VideoCapture cap(0);
    //string path = "Resources/paper.jpg";
    //imgOriginal = imread(path);
    //resize(imgOriginal, imgOriginal, Size(), 0.5, 0.4);

    while (true) {

        cap.read(img);
        // Preprocessing
        imgThre = preProcessing(img);

        // Get Contours - Biggest 
        initialPoints = getContours(imgThre);

        ///drawPoints(initialPoints, Scalar(0,0,255));
        docPoints = reorder(initialPoints);
        //drawPoints(docPoints, Scalar(0, 255, 0));

        // Warp
        imgWarp = getWarp(img, docPoints, w, h);

        //Crop
        int cropVal = 5;
        Rect roi(cropVal, cropVal, w - (2 * cropVal), h - (2 * cropVal));
        imgCrop = imgWarp(roi);

        //imshow("Image", imgOriginal);
        //imshow("Image Dilation", imgThre);
        //imshow("Image Warp", imgWarp);
        imshow("Image Crop", imgCrop);
        waitKey(1);
    }
}

在调试我的程序后，当我 push_back() 时，我发现函数“重新排序”中有一个错误。我该如何解决这个问题？

标签： c++opencvvector