MatchList::const_iterator filterOutBestMatch(const MatchList &input) {
MatchList::const_iterator result = input.begin();
if (input.size() > 1)
warning("Multiple entries found for id %d/%s", (*result)->first, getIdString((*result)->first));
for (MatchList::const_iterator i = input.begin(); i != input.end(); ++i) {
// Reduce all entries to one single entry.
//
// We use the following rules for this (in this order):
// - Prefer the entry with the higest size
// - Prefer the entry, which starts at the smallest offest
//
// TODO: These rules might not be safe for all games, but hopefully
// they will work fine. If there are any problems it should be rather
// easy to identify them, since we print out a warning for multiple
// entries found.
if ((*result)->second.desc.hint.size <= (*i)->second.desc.hint.size) {
if ((*result)->second.offset >= (*i)->second.offset)
result = i;
}
}
return result;
}
Homography meanHomography(const Array<Feat>& feats1,const Array<Feat>& feats2,const MatchList& matches) {
int nb=int(matches.size());
Matrix<double> A(2*nb,8);
Vector<double> B(2*nb);
A.fill(0);
int k=0;
// Completer: remplir A et B pour que H verifie AH=B
for (MatchList::const_iterator it=matches.begin(); it!=matches.end(); k++,it++) {
Vec2 m1=feats1[it->first].pos;
Vec2 m2=feats2[it->second].pos;
// ...
}
Matrix<double> C=pseudoInverse(A); // Moindres carr�s
if(norm(C)==0) // non invertible
return Homography(0.);
Vector<double> H=C*B;
return Homography(H.data()); // Painlesss Vector -> FVector conversion
}
Homography autoHomography(const Image<Color>&I1,const Image<Color>&I2,bool ransac=false) {
Detector d;
Array<Feat> feats1=d.run(I1);
drawFeatures(feats1);
Array<Feat> feats2=d.run(I2);
drawFeatures(feats2,IntPoint2(I1.width(),0));
MatchList matches=loweMatch(feats1,feats2,.5,true);
cout << matches.size() << " matches" << endl;
drawMatches(feats1,feats2,matches,IntPoint2(0,0),IntPoint2(I1.width(),0),1.,true);
click();
if (ransac) {
Homography H;
double outlier_thres;
double median_res = leastMedianOfSquares<4>(matches.begin(), matches.end(), HomEstimator(feats1,feats2), HomResidual(feats1,feats2),H,&outlier_thres);
MatchList inliers;
for (MatchList::const_iterator it=matches.begin(); it!=matches.end(); it++) {
if ( HomResidual(feats1,feats2)(H,*it) < outlier_thres )
inliers.push_front(*it);
}
cout << inliers.size() << " inliers" << endl;
matches=inliers;
}
return meanHomography(feats1,feats2,matches);
}