opencv-最大连通域

void LargestConnecttedComponent(Mat srcImage, Mat &dstImage) {
    Mat temp;
    Mat labels;
    srcImage.copyTo(temp);
    //1. 标记连通域
    int n_comps = connectedComponents(temp, labels, 4, CV_16U);
    vector<int> histogram_of_labels;
    for(int i = 0; i < n_comps; i++) { //初始化labels的个数为0
        histogram_of_labels.push_back(0);
    }

    int rows = labels.rows;
    int cols = labels.cols;
    for(int row = 0; row < rows; row++) { //计算每个labels的个数
        for(int col = 0; col < cols; col++) {
            histogram_of_labels.at(labels.at<unsigned short>(row, col)) += 1;
        }
    }
    histogram_of_labels.at(0) = 0; //将背景的labels个数设置为0

    //2. 计算最大的连通域labels索引
    int maximum = 0;
    int max_idx = 0;
    for(int i = 0; i < n_comps; i++) {
        if(histogram_of_labels.at(i) > maximum) {
            maximum = histogram_of_labels.at(i);
            max_idx = i;
        }
    }

    //3. 将最大连通域标记为1
    for(int row = 0; row < rows; row++) {
        for(int col = 0; col < cols; col++) {
            if(labels.at<unsigned short>(row, col) == max_idx) {
                labels.at<unsigned short>(row, col) = 255;
            } else {
                labels.at<unsigned short>(row, col) = 0;
            }
        }
    }
    //4. 将图像更改为CV_8U格式
    labels.convertTo(dstImage, CV_8U);
}