opencv 最大内接矩形笔记

include include include using namespace cv;
using namespace std;
/**

  • @brief expandEdge 扩展边界函数
  • @param img:输入图像,单通道二值图,深度为8
  • @param edge 边界数组,存放4条边界值
  • @param edgeID 当前边界号
  • @return 布尔值 确定当前边界是否可以扩展
    */
    bool expandEdge(const Mat & img, int edge[], const int edgeID)
    {
    //[1] --初始化参数
    int nc = img.cols;
    int nr = img.rows;
    switch (edgeID) {
    case 0:
    if (edge[0]>nr) return false; for (int i = edge[3]; i <= edge[1]; ++i) { if (img.at(edge[0], i) == 255)//遇见255像素表明碰到边缘线 return false; } edge[0]++; return true; break;

    case 1:
    if (edge[1]>nc) return false; for (int i = edge[2]; i <= edge[0]; ++i) { if (img.at(i, edge[1]) == 255)//遇见255像素表明碰到边缘线 return false; } edge[1]++; return true; break;

    case 2:
    if (edge[2]<0) return false; for (int i = edge[3]; i <= edge[1]; ++i) { if (img.at(edge[2], i) == 255)//遇见255像素表明碰到边缘线 return false; } edge[2]--; return true; break;

    case 3:
    if (edge[3]<0) return false; for (int i = edge[2]; i <= edge[0]; ++i) { if (img.at(i, edge[3]) == 255)//遇见255像素表明碰到边缘线 return false; } edge[3]--; return true; break;

    default:
    return false; break;

    }
    }
    /**
  • @brief 求取连通区域内接矩
  • @param img:输入图像,单通道二值图,深度为8
  • @param center:最小外接矩的中心
  • @return 最大内接矩形
  • 基于中心扩展算法
    */
    cv::Rect InSquare(Mat &img, const Point center)
    {
    // --[1]参数检测
    if (img.empty() ||img.channels()>1|| img.depth()>8)
    return Rect();

    // --[2] 初始化变量
    int edge[4];
    edge[0] = center.y + 1; //top
    edge[1] = center.x + 1; //right
    edge[2] = center.y - 1; //bottom
    edge[3] = center.x - 1; //left
    //[2] // --[3]边界扩展(中心扩散法)

    bool EXPAND[4] = { 1,1,1,1 }; //扩展标记位
    int n = 0;
    while (EXPAND[0] || EXPAND[1] || EXPAND[2] || EXPAND[3])
    {
    int edgeID = n % 4; EXPAND[edgeID] = expandEdge(img, edge, edgeID); n++;

    }
    //[3]
    //qDebug() << edge[0] << edge[1] << edge[2] << edge[3];
    Point tl = Point(edge[3], edge[0]);
    Point br = Point(edge[1], edge[2]);
    return Rect(tl, br);
    }
    int main()
    {
    bool isExistence = false;
    float first_area = 0;
    /// 加载源图像
    Mat src;
    src = https://www.it610.com/article/imread("cen.bmp", 1);
    //src = https://www.it610.com/article/imread("C:\Users\Administrator\Desktop\测试图片\xxx\20190308152516.jpg",1);
    //src = https://www.it610.com/article/PayPal下载imread("C:\Users\Administrator\Desktop\测试图片\xx\20190308151912.jpg",1);
    //src = https://www.it610.com/article/imread("C:\Users\Administrator\Desktop\测试图像\2\BfImg17(x-247 y--91 z--666)-(492,280).jpg",1);
    cvtColor(src, src, CV_RGB2GRAY);
    threshold(src, src, 100, 255, THRESH_BINARY);
    Rect ccomp;
    Point center(src.cols / 2, src.rows / 2);
    //floodFill(src, center, Scalar(255, 255, 55), &ccomp, Scalar(20, 20, 20), Scalar(20, 20, 20));
    if (src.empty())
    {
    cout << "fali" << endl;

    【opencv 最大内接矩形笔记】}
    //resize(src, src, cv::Size(496, 460), cv::INTER_LINEAR);
    imshow("src", src);
    Rect rr = InSquare(src, center);
    rectangle(src, rr, Scalar(255), 1, 8);
    imshow("src2", src);
    waitKey(0);
    getchar();
    return 0;
    }

    推荐阅读