基于DCT系数背景建模与运动目标检测算法V1.0

#include "DctDetect.h" DctDetect::DctDetect(void) { } DctDetect::DctDetect(Mat& frame ) { m_frmNum = 0; m_gridCols = 0; m_gridRows = 0; m_inc = 1.0; m_dec = 0.1; //m_threshold = 0.50; m_threshold = sqrtf(3.0)/2.0; // cos(45°)= sqrtf(2.0)/2 m_height = frame.rows; m_width = frame.cols; m_rect.x = 0; m_rect.y = 0; m_rect.width = 4; m_rect.height = 4; m_foreground.create( m_height, m_width, CV_8UC1 ); buildGrid(frame, m_rect); vector<float> coff; ELEM _elem; vector<ELEM> _data; vector<DATA> v_data; for ( int i=0; i< m_gridRows; ++i ) { v_data.clear(); for ( int j=0; j< m_gridCols; ++j ) { _data.clear(); calcDct(frame(m_grid[i][j]), coff ); _elem.m_data = coff; _elem.m_weight = m_inc; _data.push_back( _elem ); v_data.push_back(_data); } m_model.push_back(v_data); } } void DctDetect::buildGrid(Mat& frame, Rect& box) { int width = box.width; int height = box.height; BoundingBox bbox; vector<BoundingBox> inGrid; for (int y=1;y<frame.rows-height;y+= height ) { inGrid.clear(); m_gridCols = 0; for (int x=1;x<frame.cols-width;x+=width) { bbox.x = x; bbox.y = y; bbox.width = width; bbox.height = height; bbox.status = -1; bbox.prev_status = 0; bbox.count = 0; inGrid.push_back(bbox); m_gridCols++; } m_grid.push_back(inGrid); m_gridRows++; } cout<<" rows = "<< m_gridRows<<endl; cout<<" cols = "<< m_gridCols<<endl; } // 计算DCT系数 void DctDetect::calcDct(Mat& frame, vector<float>& coff) { if ( frame.empty() ) return; Mat temp; if ( 1 == frame.channels()) frame.copyTo( temp); else cvtColor( frame, temp, CV_BGR2GRAY); Mat tempMat( frame.rows, frame.cols, CV_64FC1); Mat tempDct( frame.rows, frame.cols, CV_64FC1); temp.convertTo( tempMat, tempMat.type()); dct( tempMat, tempDct, CV_DXT_FORWARD ); // DCT变换 coff.clear(); coff.push_back((float)tempDct.at<double>(0,1) ); // 取值 ( 0,1 )、( 0,2 )、( 1,0 )、( 1,1 )、( 2,0 ) coff.push_back((float)tempDct.at<double>(0,2) ); coff.push_back((float)tempDct.at<double>(1,0) ); coff.push_back((float)tempDct.at<double>(1,1) ); coff.push_back((float)tempDct.at<double>(2,0) ); if ( !temp.empty()) temp.release(); if ( !tempMat.empty()) tempMat.release(); if ( !tempDct.empty()) tempDct.release(); } // 计算距离 float DctDetect::calcDist(vector<float>& coff1, vector<float>& coff2) { float d1 = norm( coff1 ); float d2 = norm( coff2 ); float d3 = dotProduct( coff1,coff2 ); if ( d2 <0.0001 || d1==0 ) return 1.0; else return d3/(d1*d2); } // 点积 float DctDetect::dotProduct( vector<float>& coff1, vector<float>& coff2) { size_t i = 0, n = coff1.size(); assert(coff1.size() == coff2.size()); float s = 0.0f; const float *ptr1 = &coff1[0], *ptr2 = &coff2[0]; for( ; i < n; i++ ) s += (float)ptr1[i]*ptr2[i]; return s; } // 检测邻域是否有前景，有则返回true bool DctDetect::checkNeighbor(int r,int c) { int count = 0; if ( (r-1) >=0 && m_grid[r-1][c].prev_status == 1) // 上面patch count++; if ( (c+1) < m_gridCols && m_grid[r][c+1].prev_status == 1) // 右边patch count++; if ( (r+1) < m_gridRows && m_grid[r+1][c].prev_status == 1) // 下面patch count++; if ( (c-1) >= 0 && m_grid[r][c-1].prev_status == 1) // 左边patch count++; // cout<<" neighbor num = "<<count<<endl; if ( count > 0 ) return true; else return false; } void DctDetect::detect(Mat& frame) { m_frmNum++; m_foreground = 0; vector<float> coff; ELEM _elem; // 单个数据 vector<ELEM> _data; // 模型数据 for ( int i=0; i< m_gridRows; ++i ) { for ( int j=0; j< m_gridCols; ++j ) { calcDct(frame(m_grid[i][j]), coff ); _data = m_model[i][j]; int mNum = _data.size(); // 模型的个数 float dist = 0.0; float fmax = FLT_MIN; int idx = -1; for ( int k=0; k<mNum; ++k ) { dist = calcDist( coff, _data[k].m_data ); if ( dist > fmax ) { fmax = dist; idx = k; } } // 匹配完成 if ( fmax > m_threshold ) // 匹配上 { for ( int k=0; k<mNum; ++k ) { if ( idx ==k ) // 匹配上的模型权重增加 m_model[i][j][k].m_weight +=m_inc ; else m_model[i][j][k].m_weight -=m_dec; } } else // 如果没有匹配上，则标注为最可能前景 { if ( m_frmNum == 1) { m_grid[i][j].prev_status = 1; _data = m_model[i][j]; // 加入背景模型 _elem.m_data = coff; _elem.m_weight = m_inc; _data.push_back( _elem ); m_model[i][j]= _data; } m_grid[i][j].status = 1; } } // end for j } // end for i cout<<" stage one is finished ( first matched)..."<<endl; // 这里来进行前景的检测 if ( m_frmNum > 1 ) { for ( int i=0; i< m_gridRows; ++i ) { for ( int j=0; j< m_gridCols; ++j ) { bool isNeighbor = checkNeighbor(i,j); if ( isNeighbor ) // 如果邻域内有前景，则标注为前景区域 { m_foreground(m_grid[i][j]) =255; m_grid[i][j].count +=1; } else { _data = m_model[i][j]; // 加入背景模型 _elem.m_data = coff; _elem.m_weight = m_inc; _data.push_back( _elem ); m_model[i][j]= _data; } } } } cout<<" stage two is finished ( second matched)..."<<endl; // 剔除背景中值为负数的模型 /*for ( int i=0; i< m_gridRows; ++i ) { for ( int j=0; j< m_gridCols; ++j ) { vector<ELEM> _temp; _data = m_model[i][j]; int mNum = _data.size(); for ( int k=0; k<mNum; ++k ) { if ( _data[k].m_weight<0) continue; else { if ( _data[k].m_weight>20.0 ) _data[k].m_weight = 20.0; _temp.push_back( _data[k] ); } } _data.clear(); _data.insert( _data.begin(), _temp.begin(), _temp.end()); m_model[i][j]= _data; } }*/ cout<<" stage three is finished ( thdir matched)..."<<endl; chageGridStatus(); cout<<" stage four is finished ( status changes)..."<<endl; } void DctDetect::chageGridStatus() { for ( int i=0; i<m_gridRows; ++i ) { for ( int j=0; j<m_gridCols; ++j ) { m_grid[i][j].prev_status = m_grid[i][j].status ; m_grid[i][j].status = 0; } } } DctDetect::~DctDetect(void) { }