OPENCV图像处理，向量下标超出范围

Question

我正在尝试通过图像应用过滤器，滤波器窗口（3x3）的输出存储在向量中（仅丢弃零值的非零值）。我想添加向量的前四个值并将答案存储在输出图像中。运行该程序会生成错误"向量下标出范围"。不知道我在哪里做错。

Mat Diff;//input image
int window[9];
Mat road;//output image
road = Diff.clone();
for (int y = 0; y < Diff.rows; y++)
for (int x = 0; x < Diff.cols; x++)
    road.at<uchar>(y, x) = 0;
//Apply road filter
for (int y = 1; y < Diff.rows - 1; y++){
    for (int x = 1; x < Diff.cols - 1; x++){
        // Pick up window element
        window[0] = abs(Diff.at<uchar>(y - 1, x - 1) - Diff.at<uchar>(y, x));
        window[1] = abs(Diff.at<uchar>(y, x - 1) - Diff.at<uchar>(y, x));
        window[2] = abs(Diff.at<uchar>(y + 1, x - 1) - Diff.at<uchar>(y, x));
        window[3] = abs(Diff.at<uchar>(y - 1, x) - Diff.at<uchar>(y, x));
        window[4] = abs(Diff.at<uchar>(y, x) - Diff.at<uchar>(y, x));
        window[5] = abs(Diff.at<uchar>(y + 1, x) - Diff.at<uchar>(y, x));
        window[6] = abs(Diff.at<uchar>(y - 1, x + 1) - Diff.at<uchar>(y, x));
        window[7] = abs(Diff.at<uchar>(y, x + 1) - Diff.at<uchar>(y, x));
        window[8] = abs(Diff.at<uchar>(y + 1, x + 1) - Diff.at<uchar>(y, x));
        int road_detector = 0;
        vector<int>nonzero_elements;
        for (int n = 0; n < 9;n++){
            if (window[n]>0){
                nonzero_elements.push_back(window[n]);
                // select the first non-zero four values of window and sum them
                //road.at<uchar>(y, x) = window[0]+window[1]+window[2]+window[3];
                if (nonzero_elements.size() <4){
                    road_detector += nonzero_elements[n];
                }
                else{
                    // sort the window  
                    sort(nonzero_elements.begin(), nonzero_elements.end());
                    road_detector = nonzero_elements.at(0) + nonzero_elements.at(1) + nonzero_elements.at(2) + nonzero_elements.at(3);
                }
            }
        }road.at<uchar>(y, x) = road_detector;
        nonzero_elements.clear();                           
    }
}

Answer 1

说您在 window[]中都有所有负值，除了存储在最后索引中的值。现在，您将仅在nonzero_elements中推出一个元素，因此它的大小为1。但是您访问了nonzero_element的第8个元素，因此超出了范围。