/*
* compute the second order.
*/
bool harrisCorners::getSecondOrder(channel& gx,
channel& gy,
channel& fxy) const {
const parameters& par = getParameters();
fxy.resize(gx.size(),false,false);
gaussKernel2D<float> gk(par.kernelSize,par.variance);
convolution filter;
convolution::parameters filterPar;
filterPar.boundaryType = lti::Constant;
filterPar.setKernel(gk);
filter.setParameters(filterPar);
channel::iterator igx=gx.begin();
channel::iterator igxend=gx.end();
channel::iterator igy=gy.begin();
channel::iterator ifxy=fxy.begin();
float tx, ty;
while (igx!=igxend) {
tx=(*igx);
ty=(*igy);
(*igx)=tx*tx;
(*igy)=ty*ty;
(*ifxy)=tx*ty;
++igx; ++igy; ++ifxy;
}
return (filter.apply(gx) && filter.apply(gy) && filter.apply(fxy));
}
void distanceTransform::sedFiltering(channel &chnl,
bool useEightSED) const {
const float fv = 0.0f;
const int undef = -2;
matrix<point> dist(chnl.size());
int row,
col;
//init
for(row = 0; row < chnl.rows(); ++row){
for(col = 0; col < chnl.columns(); ++col){
if(chnl.at(row, col) == fv)
dist.at(row, col) = point(0, 0);
else
dist.at(row, col) = point(undef, undef);
}
}
if(useEightSED)
eightSEDFiltering(chnl, dist);
else
fourSEDFiltering(chnl, dist);
//set the distances
for(row = 0; row < chnl.rows(); ++row)
for(col = 0; col < chnl.columns(); ++col)
chnl.at(row, col) = static_cast<float>(dist.at(row, col).distanceSqr(point(0,0)));
}
/*
* compute cornerness
*/
bool harrisCorners::getCornerness(const channel& fxx,
const channel& fxy,
const channel& fyy,
const float scale,
channel& cornerness,
float& maxCornerness) const {
// we can assume that all channels are connected, but try it out if not
if ((fxx.getMode() != channel::Connected) ||
(fxy.getMode() != channel::Connected) ||
(fyy.getMode() != channel::Connected)) {
setStatusString("Channels not contigous in getCornerness");
return false;
}
if (fxx.empty() || fxy.empty() || fyy.empty()) {
cornerness.clear();
maxCornerness = 0.0f;
return false;
}
int i;
const int end = fxx.rows()*fxx.columns();
const float *const pfxx = &fxx.at(0);
const float *const pfxy = &fxy.at(0);
const float *const pfyy = &fyy.at(0);
cornerness.resize(fxx.size(),0,false,false);
float* pcor = &cornerness.at(0);
float det,trace,txx,txy,tyy,c;
float maxc = 0.0f;
for (i=0;i<end;++i) {
txx=pfxx[i];
txy=pfxy[i];
tyy=pfyy[i];
det=txx*tyy - txy*txy;
trace=txx+tyy;
c = det-scale*trace*trace;
pcor[i]=c;
if (c>maxc) {
maxc=c;
}
}
maxCornerness = maxc;
return true;
}
