void ComputeMeanAndVariance(Array2d<double>& data,Array2dC<double>& avg,Array2d<double>& cov,const bool subtractMean)
{
avg.Create(1,data.ncol); avg.Zero();
cov.Create(data.ncol,data.ncol); cov.Zero();
for(int i=0;i<data.nrow;i++)
{
for(int j=0;j<data.ncol;j++) avg.buf[j] += data.p[i][j];
for(int j=0;j<data.ncol;j++)
for(int k=0;k<data.ncol;k++)
cov.p[j][k] += data.p[i][j]*data.p[i][k];
}
const double r = 1.0/data.nrow;
for(int i=0;i<data.ncol;i++) avg.buf[i] *= r;
if(subtractMean)
{
for(int i=0;i<data.ncol;i++)
for(int j=0;j<data.ncol;j++)
cov.p[i][j] = cov.p[i][j]*r-avg.buf[i]*avg.buf[j];
}
else
{
for(int i=0;i<data.ncol;i++)
for(int j=0;j<data.ncol;j++)
cov.p[i][j] = cov.p[i][j]*r;
}
}
// The function that does the real detection
int DetectionScanner::FastScan(IntImage<double>& original,std::vector<CRect>& results,const int stepsize)
{
if(original.nrow<height+5 || original.ncol<width+5) return 0;
const int hd = height/xdiv;
const int wd = width/ydiv;
InitImage(original);
results.clear();
hist.Create(1,baseflength*(xdiv-EXT)*(ydiv-EXT));
NodeDetector* node = cascade->nodes[1];
double** pc = node->classifier.p;
int oheight = original.nrow, owidth = original.ncol;
CRect rect;
while(image.nrow>=height && image.ncol>=width)
{
InitIntegralImages(stepsize);
for(int i=2; i+height<image.nrow-2; i+=stepsize)
{
const double* sp = scores.p[i];
for(int j=2; j+width<image.ncol-2; j+=stepsize)
{
if(sp[j]<=0) continue;
int* p = hist.buf;
hist.Zero();
for(int k=0; k<xdiv-EXT; k++)
{
for(int t=0; t<ydiv-EXT; t++)
{
for(int x=i+k*hd+1; x<i+(k+1+EXT)*hd-1; x++)
{
int* ctp = ct.p[x];
for(int y=j+t*wd+1; y<j+(t+1+EXT)*wd-1; y++)
p[ctp[y]]++;
}
p += baseflength;
}
}
double score = node->thresh;
for(int k=0; k<node->classifier.nrow; k++) score += pc[k][hist.buf[k]];
if(score>0)
{
rect.top = i*oheight/image.nrow;
rect.bottom = (i+height)*oheight/image.nrow;
rect.left = j*owidth/image.ncol;
rect.right = (j+width)*owidth/image.ncol;
results.push_back(rect);
}
}
}
ResizeImage();
}
return 0;
}
// Load SVM models -- Histogram Intersectin Kernel SVM trained by libHIK
double UseSVM_CD_FastEvaluationStructure(const char* modelfile, const int m, const int upper_bound, Array2dC<double>& result)
{
std::ifstream fs(modelfile, std::fstream::binary);
if( !fs.is_open() )
{
std::cout << "SVM model " << modelfile << " can not be loaded." << std::endl;
exit(-1);
}
// Header
int rows, cols, type, channels;
fs.read((char*)&rows, sizeof(int)); // rows
fs.read((char*)&cols, sizeof(int)); // cols
fs.read((char*)&type, sizeof(int)); // type
fs.read((char*)&channels, sizeof(int)); // channels
// Data
cv::Mat mat(rows, cols, type);
fs.read((char*)mat.data, CV_ELEM_SIZE(type) * rows * cols);
int num_dim = m;
result.Create(num_dim, upper_bound);
for(int i=0; i<num_dim; i++)
for (int j = 0; j < upper_bound; j++)
{
result.p[i][j]= mat.at<double>(i, j);
}
return -0.00455891;
}
// Load SVM models -- linear SVM trained using LIBLINEAR
double UseSVM_CD_FastEvaluationStructure(const char* modelfile,const int m,Array2dC<double>& result)
{
std::ifstream in(modelfile);
if(in.good()==false)
{
std::cout<<"SVM model "<<modelfile<<" can not be loaded."<<std::endl;
exit(-1);
}
std::string buffer;
std::getline(in,buffer); // first line
std::getline(in,buffer); // second line
std::getline(in,buffer); // third line
in>>buffer;
assert(buffer=="nr_feature");
int num_dim;
in>>num_dim;
assert(num_dim>0 && num_dim==m);
std::getline(in,buffer); // end of line 4
in>>buffer;
assert(buffer=="bias");
int bias;
in>>bias;
std::getline(in,buffer); //end of line 5;
in>>buffer;
assert(buffer=="w");
std::getline(in,buffer); //end of line 6
result.Create(1,num_dim);
for(int i=0; i<num_dim; i++) in>>result.buf[i];
double rho = 0;
if(bias>=0) in>>rho;
in.close();
return rho;
}
double UseSVM_Linear_FastEvaluationStructure(const svm_model& model,const int m,Array2dC<double>& result)
{
Array2d<double> eval(1,m);
result.Create(1,m);
double rho = UseSVM_Linear_FastEvaluationStructure(model,m,eval,0);
std::copy(eval.p[0],eval.p[0]+m,result.buf);
return rho;
}
void DetectionScanner::LoadDetector(std::vector<NodeDetector::NodeType>& types,std::vector<int>& upper_bounds,std::vector<std::string>& filenames)
{
unsigned int depth = types.size();
assert(depth>0 && depth==upper_bounds.size() && depth==filenames.size());
if(cascade)
delete cascade;
cascade = new CascadeDetector;
assert(xdiv>0 && ydiv>0);
for(unsigned int i=0; i<depth; i++)
cascade->AddNode(types[i],(xdiv-EXT)*(ydiv-EXT)*baseflength,upper_bounds[i],filenames[i].c_str());
hist.Create(1,baseflength*(xdiv-EXT)*(ydiv-EXT));
}
double UseSVM_CS_Histogram_FastEvaluationStructure(const svm_model& model,const int m,const int upper_bound,Array2dC<double>& eval)
// structure for fast average histogram similarity, NOT using codebook, for BSVM Crammer-Singer and t=5 (HIK) ONLY
// There are nr_class classifiers, each taking 'm' rows of 'eval'
{
assert(model.param.svm_type == 5);
assert(model.param.kernel_type == 5);
int nr_class = model.nr_class;
// Check that the input is valid
int max_index = -1;
for(int i=0;i<model.l;i++)
{
svm_node* sv = model.SV[i];
while(sv->index!=-1)
{
if(sv->index<=0 || (sv->index>m && m<0))
{
std::cout<<"Invalid input: one feature index is out of range (<0 or >m)."<<std::endl;
exit(-1);
}
if(sv->index>max_index) max_index = sv->index;
if(sv->value<0 || sv->value>=upper_bound)
{
std::cout<<"Invalid input: one feature value is out of range (<0 or >=upper bound)"<<std::endl;
exit(-1);
}
sv++;
}
}
// eval: data structure for fast evalutation of SVMs
// eval[i*m : (i+1)*m, :] is a boundary for class i
// each row is the lookup table value for a dimension of the feature vector, corresponding to feature value 0 to (upper_bound - 1)
if(m>max_index) max_index = m;
eval.Create(nr_class*max_index,upper_bound);
// SVs, for sorting then filling the table
Array2d<int> SVs(model.l,max_index);
for(int i=0;i<model.l;i++) std::fill(SVs.p[i],SVs.p[i]+max_index,(int)0);
for(int i=0;i<model.l;i++)
{
svm_node* sv = model.SV[i];
while(sv->index!=-1)
{
SVs.p[i][sv->index-1] = (int)sv->value;
sv++;
}
}
Array2dC< sort_struct<int> > onecolumn(1,model.l); // data structure for sorting
Array2dC<double> sv_coef(1,model.l);
for(int fi=0;fi<max_index;fi++) // feature index, ranging from 0 to 'm'-1
{ // first sort a column
for(int i=0;i<model.l;i++)
{
onecolumn.buf[i].value = SVs.p[i][fi];
onecolumn.buf[i].id = i;
}
std::sort(onecolumn.buf,onecolumn.buf+model.l,Template_Less<int>);
// Now fill the table
for(int c=0;c<nr_class;c++)
{
for(int i=0;i<model.l;i++) sv_coef.buf[i] = model.sv_coef[c][i];
double coef_sum = std::accumulate(sv_coef.buf,sv_coef.buf+model.l,0.0);
int curpos = 0;
double cumsum = 0; // cumulative partial sum
for(int i=0;i<upper_bound;i++)
{
while(curpos<model.l && onecolumn.buf[curpos].value==i)
{
cumsum += sv_coef.buf[onecolumn.buf[curpos].id]*onecolumn.buf[curpos].value;
coef_sum -= sv_coef.buf[onecolumn.buf[curpos].id];
curpos++;
}
eval.p[c*m+fi][i] = cumsum + coef_sum * i;
}
}
}
return 0; // this is not used, it's here for historical reasons
}
double UseSVM_Histogram_FastEvaluationStructure(const svm_model& model,const int m,const int upper_bound,Array2dC<double>& eval,const bool normalize)
// structure for fast average histogram similarity, NOT using codebook, to be used with LIBSVM classifiers
// This function should work with all cases (one-class, nu-SVM, C-SVC, binary, multi-class, etc)
{
int nr_class = model.nr_class;
int num_classifier = nr_class*(nr_class-1)/2;
if(model.param.svm_type == ONE_CLASS || model.param.svm_type == EPSILON_SVR || model.param.svm_type == NU_SVR)
{
nr_class = 1;
num_classifier = 1;
}
// 'start[i]': index of where the SVs for class i starts
Array2dC<int> start(1,nr_class);
start.buf[0] = 0;
for(int i=1;i<nr_class;i++) start.buf[i] = start.buf[i-1]+model.nSV[i-1];
// Check that the input is valid
int max_index = -1;
for(int i=0;i<nr_class;i++)
{
for(int j=0;j<model.nSV[i];j++)
{
svm_node* sv = model.SV[start.buf[i]+j];
while(sv->index!=-1)
{
if(sv->index<=0 || (sv->index>m && m<0))
{
std::cout<<"Invalid input: one feature index is out of range (<0 or >m)."<<std::endl;
exit(-1);
}
if(sv->index>max_index) max_index = sv->index;
if(sv->value<0 || sv->value>=upper_bound)
{
std::cout<<"Invalid input: one feature value is out of range (<0 or >=upper bound)"<<std::endl;
exit(-1);
}
sv++;
}
}
}
// eval: data structure for fast evalutation of SVMs
// eval[(i*nr_class+j)*m : (i*nr_class+j+1)*m, :] is a sub-classifier of class i versus class j
// each row is the lookup table value for a dimension of the feature vector, corresponding to feature value 0 to (upper_bound - 1)
// refer to our ICCV 2009 paper
if(m>max_index) max_index = m;
eval.Create(num_classifier*max_index,upper_bound);
int pos = 0; // index of the classifier
for(int i=0;i<nr_class;i++)
{
for(int j=i+1;j<nr_class;j++)
{ // sub-classifier for class i versus class j
int size = model.nSV[i] + model.nSV[j]; // number of SVs in this sub-classifier
Array2dC<double> sv_coef(1,size); // prepare \alpha values
for(int k=0;k<model.nSV[i];k++) sv_coef.buf[k] = model.sv_coef[j-1][k+start.buf[i]];
for(int k=0;k<model.nSV[j];k++) sv_coef.buf[model.nSV[i]+k] = model.sv_coef[i][k+start.buf[j]];
// normalize these \alpha values and \rho
double coef_sum = std::accumulate(sv_coef.buf,sv_coef.buf+model.nSV[i],0.0);
coef_sum = 1.0/coef_sum;
if(normalize) for(int k=0;k<size;k++) sv_coef.buf[k] *= coef_sum;
if(normalize) model.rho[pos] *= coef_sum;
// SVs of this sub-classifier, for sorting then filling the table
Array2d<int> SVs(size,max_index);
for(int k=0;k<size;k++) std::fill(SVs.p[k],SVs.p[k]+max_index,(int)0);
for(int k=0;k<model.nSV[i];k++)
{
svm_node* sv = model.SV[start.buf[i]+k];
while(sv->index!=-1)
{
SVs.p[k][sv->index-1] = (int)sv->value;
sv++;
}
} // SV from class i
for(int k=0;k<model.nSV[j];k++)
{
svm_node* sv = model.SV[start.buf[j]+k];
while(sv->index!=-1)
{
SVs.p[k+model.nSV[i]][sv->index-1] = (int)sv->value;
sv++;
}
} // SV from class j
Array2dC< sort_struct<int> > onecolumn(1,size); // data structure for sorting
for(int fi=0;fi<max_index;fi++) // feature index, ranging from 0 to 'm'-1
{ // first sort a column
coef_sum = std::accumulate(sv_coef.buf,sv_coef.buf+size,0.0); // should this be 0?
for(int k=0;k<size;k++)
{
onecolumn.buf[k].value = SVs.p[k][fi];
onecolumn.buf[k].id = k;
}
std::sort(onecolumn.buf,onecolumn.buf+size,Template_Less<int>);
// Now fill the table
int curpos = 0;
double cumsum = 0; // cumulative partial sum
for(int k=0;k<upper_bound;k++)
{
while(curpos<size && onecolumn.buf[curpos].value==k)
{
cumsum += sv_coef.buf[onecolumn.buf[curpos].id]*onecolumn.buf[curpos].value;
coef_sum -= sv_coef.buf[onecolumn.buf[curpos].id];
curpos++;
}
eval.p[pos*m+fi][k] = cumsum + coef_sum * k;
}
}
pos++;
}
}
return -model.rho[0]; // this is not used, it's here for historical reasons
}
