quality.cpp
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#include <openbr_plugin.h>
#include "core/common.h"
using namespace br;
namespace br
{
/*!
* \ingroup transforms
* \brief Impostor Uniqueness Measure \cite klare12
* \author Josh Klontz \cite jklontz
*/
class IUMTransform : public Transform
{
Q_OBJECT
Q_PROPERTY(br::Distance* distance READ get_distance WRITE set_distance RESET reset_distance STORED false)
Q_PROPERTY(double mean READ get_mean WRITE set_mean RESET reset_mean)
Q_PROPERTY(double stddev READ get_stddev WRITE set_stddev RESET reset_stddev)
BR_PROPERTY(br::Distance*, distance, Factory<Distance>::make(".Dist(L2)"))
BR_PROPERTY(double, mean, 0)
BR_PROPERTY(double, stddev, 1)
br::TemplateList impostors;
float calculateIUM(const Template &probe, const TemplateList &gallery) const
{
QList<float> scores = distance->compare(gallery, probe);
float min, max;
Common::MinMax(scores, &min, &max);
double mean;
Common::Mean(scores, &mean);
return (max-mean)/(max-min);
}
void train(const TemplateList &data)
{
distance->train(data);
impostors = data;
QList<float> iums; iums.reserve(impostors.size());
QList<int> labels = impostors.labels<int>();
for (int i=0; i<data.size(); i++) {
TemplateList subset = impostors;
for (int j=subset.size()-1; j>=0; j--)
if (labels[j] == labels[i])
subset.removeAt(j);
iums.append(calculateIUM(impostors[i], subset));
}
Common::MeanStdDev(iums, &mean, &stddev);
}
void project(const Template &src, Template &dst) const
{
dst = src;
float ium = calculateIUM(src, impostors);
dst.file.insert("IUM", ium);
dst.file.insert("IUM_Bin", ium < mean-stddev ? 0 : (ium < mean+stddev ? 1 : 2));
}
void store(QDataStream &stream) const
{
distance->store(stream);
stream << mean << stddev << impostors;
}
void load(QDataStream &stream)
{
distance->load(stream);
stream >> mean >> stddev >> impostors;
}
};
BR_REGISTER(Transform, IUMTransform)
/* Kernel Density Estimator */
struct KDE
{
float min, max;
QList<float> bins;
KDE() : min(0), max(1) {}
KDE(const QList<float> &scores)
{
Common::MinMax(scores, &min, &max);
double h = Common::KernelDensityBandwidth(scores);
const int size = 255;
bins.reserve(size);
for (int i=0; i<size; i++)
bins.append(Common::KernelDensityEstimation(scores, min + (max-min)*i/(size-1), h));
}
float operator()(float score) const
{
if (score <= min) return bins.first();
if (score >= max) return bins.last();
const float x = (score-min)/(max-min)*bins.size();
const float y1 = bins[floor(x)];
const float y2 = bins[ceil(x)];
return y1 + (y2-y1)*(x-floor(x));
}
};
QDataStream &operator<<(QDataStream &stream, const KDE &kde)
{
return stream << kde.min << kde.max << kde.bins;
}
QDataStream &operator>>(QDataStream &stream, KDE &kde)
{
return stream >> kde.min >> kde.max >> kde.bins;
}
/* Non-match Probability */
struct NMP
{
KDE genuine, impostor;
NMP() {}
NMP(const QList<float> &genuineScores, const QList<float> &impostorScores)
: genuine(genuineScores), impostor(impostorScores) {}
float operator()(float score) const { float g = genuine(score); return g / (impostor(score) + g); }
};
QDataStream &operator<<(QDataStream &stream, const NMP &nmp)
{
return stream << nmp.genuine << nmp.impostor;
}
QDataStream &operator>>(QDataStream &stream, NMP &nmp)
{
return stream >> nmp.genuine >> nmp.impostor;
}
/*!
* \ingroup distances
* \brief Impostor Uniqueness Distance \cite klare12
* \author Josh Klontz \cite jklontz
*/
class IUMDistance : public Distance
{
Q_OBJECT
Q_PROPERTY(br::Distance* distance READ get_distance WRITE set_distance RESET reset_distance STORED false)
BR_PROPERTY(br::Distance*, distance, Factory<Distance>::make(".Dist(L2)"))
QList<NMP> nmps;
void train(const TemplateList &src)
{
distance->train(src);
const QList<float> labels = src.labels<float>();
QScopedPointer<MatrixOutput> memoryOutput(dynamic_cast<MatrixOutput*>(Output::make(".Matrix", FileList(src.size()), FileList(src.size()))));
distance->compare(src, src, memoryOutput.data());
const int IUM_Bins = 3;
QVector< QList<float> > genuineScores(IUM_Bins), impostorScores(IUM_Bins);
for (int i=0; i<src.size(); i++)
for (int j=0; j<i; j++) {
const float score = memoryOutput.data()->data.at<float>(i, j);
const int bin = src[i].file.getInt("IUM_Bin");
if (labels[i] == labels[j]) genuineScores[bin].append(score);
else impostorScores[bin].append(score);
}
for (int i=0; i<IUM_Bins; i++)
nmps.append(NMP(genuineScores[i], impostorScores[i]));
}
float _compare(const Template &target, const Template &query) const
{
return nmps[query.file.getInt("IUM_Bin")](distance->compare(target, query));
}
void store(QDataStream &stream) const
{
distance->store(stream);
stream << nmps;
}
void load(QDataStream &stream)
{
distance->load(stream);
stream >> nmps;
}
};
BR_REGISTER(Distance, IUMDistance)
} // namespace br
#include "quality.moc"