魔棒工具--RegionGrow算法简介

struct Node 
{
    int x;
    int y;
    Node* next;
};

void MyTreasureBox::RegionGrow(const IplImage* src, IplImage* dst, int seedx, int seedy, int threshold, bool flag)
{
    if(!src || src->nChannels != 1)return ;

    int width = src->width;
    int height = src->height;
    int srcwidthstep = src->widthStep;
    uchar* img = (uchar*)src->imageData;

    //成长区域
    cvZero(dst);

    //标记每个像素点是否被计算过
    IplImage* M = cvCreateImage(cvSize(width, height), 8, 1);
    int Mwidthstep = M->widthStep;

    cvZero(M);
    M->imageData[seedy * Mwidthstep + seedx] = 1;    //种子点位置为1，其它位置为0

    CvScalar cur = CV_RGB(255,255,255);
    cvSet2D(dst, seedy, seedx, cur);

    //队列的两端
    int start = 0;
    int end = 1;

    Node *queue = new Node;
    queue->x = seedx;
    queue->y = seedy;
    queue->next = NULL;
    Node *first = queue;
    Node *last = queue;

    while (end - start > 0)
    {
        int x = first->x;
        int y = first->y;
        uchar pixel = (uchar)img[y * srcwidthstep + x];

        for (int yy = -1; yy<=1; yy++)
        {
            for (int xx = -1; xx<=1; xx++)
            {
                if(flag)
                    if ( abs(yy) && abs(xx))
                        continue;

                int cx = x + xx;
                int cy = y + yy;
                if (cx >= 0 && cx <width && cy >=0 && cy < height)
                {
                    if (abs(img[cy * srcwidthstep + cx] - pixel) <= threshold && M->imageData[cy * Mwidthstep + cx] != 1)
                    {
                        Node *node = new Node;
                        node->x = cx;
                        node->y = cy;
                        node->next = NULL;

                        end++;
                        last->next = node;
                        last = node;

                        M->imageData[cy * Mwidthstep + cx] = 1;

                        cvSet2D(dst, cy, cx, cur);
                    }
                }
            }
        }
        Node* temp = first;
        first = first->next;
        delete temp;
        start++;
    }

    cvReleaseImage(&M);
}