Zhang-Suen 图像骨架提取算法的原理和OpenCV实现

记录一下图像骨架提取算法，转载至 两种图像骨架提取算法的研究(1)原理部分

基于OpenCV的实现代码如下，代码部分参考 opencv骨架提取/图像细化

void thinImage(Mat & srcImg) {
    vector<Point> deleteList;
    int neighbourhood[9];
    int nl = srcImg.rows;
    int nc = srcImg.cols;
    bool inOddIterations = true;
    while (true) {
        for (int j = 1; j < (nl - 1); j++) {
            uchar* data_last = srcImg.ptr<uchar>(j - 1);
            uchar* data = srcImg.ptr<uchar>(j);
            uchar* data_next = srcImg.ptr<uchar>(j + 1);
            for (int i = 1; i < (nc - 1); i++) {
                if (data[i] == 255) {
                    int whitePointCount = 0;
                    neighbourhood[0] = 1;
                    if (data_last[i] == 255) neighbourhood[1] = 1;
                    else  neighbourhood[1] = 0;
                    if (data_last[i + 1] == 255) neighbourhood[2] = 1;
                    else  neighbourhood[2] = 0;
                    if (data[i + 1] == 255) neighbourhood[3] = 1;
                    else  neighbourhood[3] = 0;
                    if (data_next[i + 1] == 255) neighbourhood[4] = 1;
                    else  neighbourhood[4] = 0;
                    if (data_next[i] == 255) neighbourhood[5] = 1;
                    else  neighbourhood[5] = 0;
                    if (data_next[i - 1] == 255) neighbourhood[6] = 1;
                    else  neighbourhood[6] = 0;
                    if (data[i - 1] == 255) neighbourhood[7] = 1;
                    else  neighbourhood[7] = 0;
                    if (data_last[i - 1] == 255) neighbourhood[8] = 1;
                    else  neighbourhood[8] = 0;
                    for (int k = 1; k < 9; k++) {
                        whitePointCount += neighbourhood[k];
                    }
                    if ((whitePointCount >= 2) && (whitePointCount <= 6)) {
                        int ap = 0;
                        if ((neighbourhood[1] == 0) && (neighbourhood[2] == 1)) ap++;
                        if ((neighbourhood[2] == 0) && (neighbourhood[3] == 1)) ap++;
                        if ((neighbourhood[3] == 0) && (neighbourhood[4] == 1)) ap++;
                        if ((neighbourhood[4] == 0) && (neighbourhood[5] == 1)) ap++;
                        if ((neighbourhood[5] == 0) && (neighbourhood[6] == 1)) ap++;
                        if ((neighbourhood[6] == 0) && (neighbourhood[7] == 1)) ap++;
                        if ((neighbourhood[7] == 0) && (neighbourhood[8] == 1)) ap++;
                        if ((neighbourhood[8] == 0) && (neighbourhood[1] == 1)) ap++;
                        if (ap == 1) {
                            if (inOddIterations && (neighbourhood[3] * neighbourhood[5] * neighbourhood[7] == 0)
                                && (neighbourhood[1] * neighbourhood[3] * neighbourhood[5] == 0)) {
                                deleteList.push_back(Point(i, j));
                            }
                            else if (!inOddIterations && (neighbourhood[1] * neighbourhood[5] * neighbourhood[7] == 0)
                                && (neighbourhood[1] * neighbourhood[3] * neighbourhood[7] == 0)) {
                                deleteList.push_back(Point(i, j));
                            }
                        }
                    }
                }
            }
        }
        if (deleteList.size() == 0)
            break;
        for (size_t i = 0; i < deleteList.size(); i++) {
            Point tem;
            tem = deleteList[i];
            uchar* data = srcImg.ptr<uchar>(tem.y);
            data[tem.x] = 0;
        }
        deleteList.clear();

        inOddIterations = !inOddIterations;
    }
}

原图和细化结果如下：