BDIP和BVLC纹理分析

Young Deok Chun 等人提出了基于 BVLC 矩和 BDIP 矩的一种纹理分析方法。BVLC 能显示粗糙和光滑特性，BDIP 能够很好的提取波谷和边缘。它们直接在彩色空间上进行处理，能有效的结合颜色特征。

BDIP&BVLC

BDIP（block difference of inverse probabilities），基于块的逆转概率。描述了在一个M*M大小的块内，像素值变化的快慢，计算的BDIP值越大，原图像像素值变化越剧烈。
BVLC(block-based of variation of local correlation coefficients)，基于块的局部相关系数。描述了一个像素点与周围四个方向（-90， 0， -45， 45）的相关度，计算的BVLC值越大，原图像越粗糙。

---

 

I(i, j)表示属于M*M块中某一个像素值 。

---

 

 

四个方向位移。

像素平移示意图：

 

 k，l分别表示水平和垂直移动 ，I(i, j)表示属于M*M块中某一个像素值，O（4）表示四个平移方向 
σ（k，l）表示在平移后M*M像素块里的标准差 ，σ（0，0）表示当前M*M块的标准差 
μ（k，l）表示在平移后M*M像素块里的均值 ，μ（0，0）表示当前M*M块的均值 

 

 

---

 

 

 BDIP code:

void bdip(const Mat& src)
{
    Mat bdip;
    bdip = src.clone();

    int nRows;
    int nCols;
    nRows = src.rows;
    nCols = src.cols;
    //计算bdip特征图
    for(int r = 0; r < nRows; ++r)
    {
        for(int c = 0; c < nCols; ++c)
        {
            float blockValue = 0.0;
            int blockSum = 0;
            int blockMax = 0;

            //边缘不做考虑
            if(0 == r || nRows - 1 == r ||
                0 == c || nCols - 1 == c)
            {
                blockValue = 0;
            }
            else
            {
                uchar v1, v2, v3, v4;
                v1 = src.ptr<uchar>(r)[c];
                v2 = src.ptr<uchar>(r)[c + 1];
                v3 = src.ptr<uchar>(r + 1)[c];
                v4 = src.ptr<uchar>(r + 1)[c + 1];

                blockSum = v1 + v2 + v3 + v4;
                blockMax = MAX(MAX(v1, v2), MAX(v3, v4));
                blockValue = 4 - blockSum*1.0/blockMax;
            }

            bdip.ptr<uchar>(r)[c] = 64*blockValue;
        }
    }

#if 1
    imshow("bdip", bdip);
    cvWaitKey(0);
#endif

    return;
}

BVLC code:

struct  SHIFTDIRECTION
{
    int x;
    int y;
};
const SHIFTDIRECTION shift[5] = {0, 0, 1, 0, 0, 1, 1, 1, 0, 1};

void bvlc(const Mat& src)
{
    int nRows;
    int nCols;
    nRows = src.rows;
    nCols = src.cols;

    //填充边界
    Mat tmp;
    copyMakeBorder(src, tmp, 2, 2, 2, 2,BORDER_REFLECT);
    tmp.convertTo(tmp, CV_32FC1, 1.0, 0);

    Mat bvlc;
    bvlc = src.clone();

    //计算blvc特征图
    for(int r = 2; r < nRows + 2; ++r)
    {
        for(int c = 2; c < nCols + 2; ++c)
        {
            float variance[5] = {0.0};
            float mean[5] = {0.0};
            float value[4] = {0,0};

            for(int i = 0; i < 5; ++i)
            {
                int curR = r + shift[i].x;
                int curC = c + shift[i].y;

                //计算平移后四个像素均值、方差
                if(i < 4)
                {
                    mean[i] = 
                        tmp.ptr<float>(curR)[curC] + 
                        tmp.ptr<float>(curR + 1)[curC] +
                        tmp.ptr<float>(curR)[curC + 1] + 
                        tmp.ptr<float>(curR + 1)[curC + 1];
                    mean[i] /= 4;

                    variance[i] = 
                        pow((tmp.ptr<float>(curR)[curC] - mean[i]), 2) + 
                        pow((tmp.ptr<float>(curR + 1)[curC] - mean[i]), 2) + 
                        pow((tmp.ptr<float>(curR)[curC + 1] - mean[i]), 2) + 
                        pow((tmp.ptr<float>(curR + 1)[curC + 1] - mean[i]), 2);
                }

                //最后一个块的位置方向与前三块有区别
                else
                {
                    mean[i] = 
                        tmp.ptr<float>(curR)[curC] + 
                        tmp.ptr<float>(curR - 1)[curC] +
                        tmp.ptr<float>(curR)[curC + 1] + 
                        tmp.ptr<float>(curR - 1)[curC + 1];  
                    mean[i] /= 4;

                    variance[i] = 
                        pow((tmp.ptr<float>(curR)[curC] - mean[i]), 2) + 
                        pow((tmp.ptr<float>(curR - 1)[curC] - mean[i]), 2) + 
                        pow((tmp.ptr<float>(curR)[curC + 1] - mean[i]), 2) + 
                        pow((tmp.ptr<float>(curR - 1)[curC + 1] - mean[i]), 2);
                }


                variance[i] /= 4;
                variance[i] = sqrt(variance[i]);
            }   

            //计算四个方向块与原块的相关系数value[i]
            for(int i = 1; i < 5; ++i)
            {   
                value[i - 1] = 
                    tmp.ptr<float>(r)[c]*tmp.ptr<float>(r + shift[i].x)[c +shift[i].y] - mean[0]*mean[i] +
                    tmp.ptr<float>(r + 1)[c]*tmp.ptr<float>(r + shift[i].x)[c +shift[i].y] - mean[0]*mean[i] +
                    tmp.ptr<float>(r)[c + 1]*tmp.ptr<float>(r + shift[i].x)[c +shift[i].y] - mean[0]*mean[i] +
                    tmp.ptr<float>(r + 1)[c + 1]*tmp.ptr<float>(r + shift[i].x)[c +shift[i].y] - mean[0]*mean[i];


                value[i - 1] /= 4;
                value[i - 1] /= (variance[0]*variance[i]);
            }

            //获取最大和最小相关系数
            float max = value[0];
            float min = value[0];

            for(int i = 0; i < 4; ++i)
            {
                if(value[i] > max)
                {
                    max = value[i];
                }

                if(value[i] < min)
                {
                    min = value[i];
                }
            }


            //计算BLVC数值
            bvlc.ptr<uchar>(r - 2)[c - 2] = max - min;
        }
    }

#if 1
    imshow("bvlc", bvlc);
    waitKey(0);
#endif

    return;
}

 

---

 

 

【转载自】

BDIP-BVLC纹理 - xxxxyxxxx的博客 - CSDN博客 https://blog.csdn.net/xxxxyxxxx/article/details/76358491

Image retrieval using bdip and bvlc moments_百度学术 http://xueshu.baidu.com/usercenter/paper/show?paperid=6fe4e1826e57f7007558cb9414214fd3&site=xueshu_se