局部二值模式LBP（Local Binary Pattern）實現代碼

            局部二值模式LBP由於其簡單、高效在目標檢測、目標識別、映像檢索等領域得到了廣泛的應用。現如今，LBP的變體不下上十種，如VLBP、SILBP等。要瞭解更多關於LBP的知識可以參考：紋理分類-全域特徵LBP及相關文獻。

          下面介紹的三種LBP運算元的區別見：

            本文不介紹LBP的理論知識，只是簡單的說說LBP及其變體的實現：

            1）最原始的LBP運算元的實現代碼           

void lbp( Mat& _src, Mat& _dst) {if ( -_dst.empty())_dst.create(_src.rows, _src.cols, CV_8UC1);_dst = cv::Scalar::all(0);// calculate patternsfor(int i=1;i<_src.rows-1;i++){for(int j=1;j<_src.cols-1;j++) {uchar center = _src.at<uchar>(i,j);unsigned char code = 0;code |= (_src.at<uchar>(i-1,j-1) >= center) << 7;code |= (_src.at<uchar>(i-1,j) >= center) << 6;code |= (_src.at<uchar>(i-1,j+1) >= center) << 5;code |= (_src.at<uchar>(i,j+1) >= center) << 4;code |= (_src.at<uchar>(i+1,j+1) >= center) << 3;code |= (_src.at<uchar>(i+1,j) >= center) << 2;code |= (_src.at<uchar>(i+1,j-1) >= center) << 1;code |= (_src.at<uchar>(i,j-1) >= center) << 0;_dst.at<unsigned char>(i,j) = code;}}}

         2）帶有容忍銀子的LBP運算元

void lbp_with_factor( Mat& _src, Mat& _dst, uchar factor) // factor default 3{if ( -_dst.empty())_dst.create(_src.rows, _src.cols, CV_8UC1);_dst = cv::Scalar::all(0);// calculate patternsfor(int i=1;i<_src.rows-1;i++){for(int j=1;j<_src.cols-1;j++) {uchar center = _src.at<uchar>(i,j)+factor;unsigned char code = 0;code |= (_src.at<uchar>(i-1,j-1) >= center) << 7;code |= (_src.at<uchar>(i-1,j) >= center) << 6;code |= (_src.at<uchar>(i-1,j+1) >= center) << 5;code |= (_src.at<uchar>(i,j+1) >= center) << 4;code |= (_src.at<uchar>(i+1,j+1) >= center) << 3;code |= (_src.at<uchar>(i+1,j) >= center) << 2;code |= (_src.at<uchar>(i+1,j-1) >= center) << 1;code |= (_src.at<uchar>(i,j-1) >= center) << 0; _dst.at<unsigned char>(i,j) = code;}}}

         3）帶有乘性因子的LBP運算元

// 這裡需要採用2個字元來編碼，如00、01、10、11void lbp_with_factor( Mat& _src, Mat& _dst, float factor)  // facotr default 0.1{if ( -_dst.empty())_dst.create(_src.rows, _src.cols, CV_8UC1);_dst = cv::Scalar::all(0);// calculate patternsfor(int i=1;i<_src.rows-1;i++){for(int j=1;j<_src.cols-1;j++) {uchar center = _src.at<uchar>(i,j);int up = center*(1.0+factor);int down = center*(1.0+factor);unsigned char code = 0;/*code |= (_src.at<uchar>(i-1,j-1) >= center ) << 7;code |= (_src.at<uchar>(i-1,j) >= center) << 6;code |= (_src.at<uchar>(i-1,j+1) >= center) << 5;code |= (_src.at<uchar>(i,j+1) >= center) << 4;code |= (_src.at<uchar>(i+1,j+1) >= center) << 3;code |= (_src.at<uchar>(i+1,j) >= center) << 2;code |= (_src.at<uchar>(i+1,j-1) >= center) << 1;code |= (_src.at<uchar>(i,j-1) >= center) << 0; _dst.at<unsigned char>(i,j) = code;*/}}}

        欲瞭解更多參考論文：Modeling Pixel Process with Scale Invariant Local Patterns for Background Subtraction in Complex Scenes。