c++ - 段错误 : 11, 在 vector 中提取数据

Question

我正在尝试使用 opencv 和 C++ 编写程序。我有一个图像，我正在尝试获取位于 (x, y) 点的确定像素的饱和度值。我用下一句来做:

saturation_level = hsv_chanels[1].at<uchar>(x, y); 

问题是程序构建正常，但当我尝试运行时，它有时运行良好，有时会因以下错误而终止:

段错误:11

有人知道为什么会出现这个错误吗？我读到这个错误是由于我的计算机内存而出现的，但我不知道为什么它只是偶尔出现。

编辑:

这是我调用来查找单应性的函数:

Mat ObtenHomografiaSuelo (vector <KeyPoint> keypoints1, vector <KeyPoint> keypoints2, Mat imagen1, Mat imagen2){
    //*****************************************************************************
    //Find homography mat
    //*****************************************************************************
    vector < Point2f > image_points[2];
    int cont = 0;

    vector<Mat> chanels_hsv1;    //[0]->H, [1]->S, [2]->V
    split( image1, chanels_hsv1 );
    vector<Mat> chanels_hsv2;
    split( image2, chanels_hsv2 );


    for(vector<KeyPoint>::const_iterator it = keypoints1.begin(); it!= keypoints1.end(); ++it){
        // Get the position of left keypoints
        float x = (it->pt.x);
        float y = (it->pt.y);

        cout << "1" << endl;
        float saturation_level = chanels_hsv1[1].at<uchar>(x, y);
        cout << "2" << endl;
        double max_level = 70.0;
        cout << "3" << endl;
        if ((y < camSize.height/4) && (saturatio_level < max_level) ){
            cout << "1:" << endl;
            waitKey (100);
            cout << "y: " << y;
            cout << "         Saturation_Level: " << nivel_saturacion << endl;
            image_points[0].push_back(Point2f(x,y));
            cout << "done" << endl;
            cont ++;
        }

    }

    cont = 0;
    for (vector<KeyPoint>::const_iterator it = keypoints2.begin(); it!=keypoints2.end(); ++it) {
        // Get the position of left keypoints
        float x = (it->pt.x);
        float y = (it->pt.y);
        float saturation_level = chanels_hsv2[1].at<uchar>(x, y);
        double max_level = 70.0;

        if ((y < (camSize.height)/4) && (saturation_level < max_level)){
            cout << "2" << endl;
            waitKey (100);
            cout << "y: " << y;
            cout << "         Saturation_Level: " << nivel_saturacion << endl;
            image_points[1].push_back(Point2f(x,y));
            cont ++;
        }
    }
    cout << "We are obtain: " << cont << " points to do the homography" << endl;
    waitKey();


    Mat H;
    H = Mat::zeros(4, 4, CV_64F);
    if (cont < 4) {
        cout << "Few points to do the homography" << endl;
    }
    else{
        if (image_points[0].size() > image_points[1].size()){
            image_points[0].resize(image_points[1].size());
        }
        else if (image_points[1].size() > image_points[0].size()){
            image_points[1].resize(image_points[0].size());
        }

        H = findHomography (image_points[0], image_points[1], CV_RANSAC, 3);
        cout << "done_matrix" << endl;

    }

    return H;
}

在调用该函数之前，我使用 Harris 或任何其他检测器检测关键点，并且我传递给该函数的图像是由 cvtColor 函数转换的 HSV_image。

错误出现在我之前提到的行中，因为在终端中我可以看到:

1

段错误:11

Answer 1

我刚刚完成更正错误，我认为这是因为我没有有效地使用我的功能。我使用两个“for”语句来交叉我检测到的两个关键点 vector ，错误有时出现在第一个，而其他错误出现在第二个。我真的不知道为什么会出现错误，我只是更改了我的代码以更有效地进行相同的思考，最终它起作用了。

我只是改变了这一行:

for(vector<KeyPoint>::const_iterator it = keypoints1.begin(); it!= keypoints1.end(); ++it){
        // Get the position of left keypoints
        float x = (it->pt.x);
        float y = (it->pt.y);

        cout << "1" << endl;
        float saturation_level = chanels_hsv1[1].at<uchar>(x, y);
        cout << "2" << endl;
        double max_level = 70.0;
        cout << "3" << endl;
        if ((y < camSize.height/4) && (saturatio_level < max_level) ){
            cout << "1:" << endl;
            waitKey (100);
            cout << "y: " << y;
            cout << "         Saturation_Level: " << nivel_saturacion << endl;
            image_points[0].push_back(Point2f(x,y));
            cout << "done" << endl;
            cont ++;
        }
cont = 0;
    for (vector<KeyPoint>::const_iterator it = keypoints2.begin(); it!=keypoints2.end(); ++it) {
        // Get the position of left keypoints
        float x = (it->pt.x);
        float y = (it->pt.y);
        float saturation_level = chanels_hsv2[1].at<uchar>(x, y);
        double max_level = 70.0;

        if ((y < (camSize.height)/4) && (saturation_level < max_level)){
            cout << "2" << endl;
            waitKey (100);
            cout << "y: " << y;
            cout << "         Saturation_Level: " << nivel_saturacion << endl;
            image_points[1].push_back(Point2f(x,y));
            cont ++;
        }
    }

通过这些:

for (int i = 0; i < good_matches.size(); i++) {
        int idx1=good_matches[i].queryIdx;
        int idx2=good_matches[i].trainIdx;
        if (((keypoints[0][idx1].pt.y < (camSize.height/4)) && (canales_hsv1[1].at<uchar>(keypoints[0][idx1].pt.x, keypoints[0][idx1].pt.y) < nivel_maximo)) || ((keypoints[1][idx2].pt.y < (camSize.height/4)) && (canales_hsv2[1].at<uchar>(keypoints[1][idx1].pt.x, keypoints[1][idx2].pt.y) < nivel_maximo)) ) {
            cout << "entro" << endl;
            matched_points[0].push_back(keypoints[0][idx1].pt);
            matched_points[1].push_back(keypoints[1][idx2].pt);
            contador ++;
        }
    }

目前我只穿过匹配的关键点，而不是所有的关键点，它需要较少的计算机操作，现在可以正常工作。