ErrorMinimizer.cpp

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// kate: replace-tabs off; indent-width 4; indent-mode normal
// vim: ts=4:sw=4:noexpandtab
/*
 
Copyright (c) 2010--2012,
François Pomerleau and Stephane Magnenat, ASL, ETHZ, Switzerland
You can contact the authors at <f dot pomerleau at gmail dot com> and
<stephane at magnenat dot net>
 
All rights reserved.
 
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
    * Redistributions of source code must retain the above copyright
      notice, this list of conditions and the following disclaimer.
    * Redistributions in binary form must reproduce the above copyright
      notice, this list of conditions and the following disclaimer in the
      documentation and/or other materials provided with the distribution.
    * Neither the name of the <organization> nor the
      names of its contributors may be used to endorse or promote products
      derived from this software without specific prior written permission.
 
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL ETH-ASL BE LIABLE FOR ANY
DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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*/
 
#include "PointMatcher.h"
#include "PointMatcherPrivate.h"
 
// ErrorElements
 
template<typename T>
PointMatcher<T>::ErrorMinimizer::ErrorElements::ErrorElements():
        reading(DataPoints()),
        reference(DataPoints()),
        weights(OutlierWeights()),
        matches(Matches()),
        nbRejectedMatches(-1),
        nbRejectedPoints(-1),
        pointUsedRatio(-1.0),
        weightedPointUsedRatio(-1.0)
{
}
 
template<typename T>
PointMatcher<T>::ErrorMinimizer::ErrorElements::ErrorElements(const DataPoints& requestedPts, const DataPoints& sourcePts, const OutlierWeights& outlierWeights, const Matches& matches)
{
        typedef typename Matches::Ids Ids;
        typedef typename Matches::Dists Dists;
        
        assert(matches.ids.rows() > 0);
        assert(matches.ids.cols() > 0);
        assert(matches.ids.cols() == requestedPts.features.cols()); //nbpts
        assert(outlierWeights.rows() == matches.ids.rows());  // knn
        
        const int knn = outlierWeights.rows();
        const int dimFeat = requestedPts.features.rows();
        const int dimReqDesc = requestedPts.descriptors.rows();
        const int dimReqTime = requestedPts.times.rows();
 
        // Count points with no weights
        const int pointsCount = (outlierWeights.array() != 0.0).count();
        if (pointsCount == 0)
                throw ConvergenceError("ErrorMnimizer: no point to minimize");
 
        Matrix keptFeat(dimFeat, pointsCount);
        
        Matrix keptDesc;
        if(dimReqDesc > 0)
                keptDesc = Matrix(dimReqDesc, pointsCount);
        
        Int64Matrix keptTime;
        if(dimReqTime > 0)
                keptTime = Int64Matrix(dimReqTime, pointsCount);
        
        Matches keptMatches (Dists(1,pointsCount), Ids(1, pointsCount));
        OutlierWeights keptWeights(1, pointsCount);
 
        int j = 0;
        int rejectedMatchCount = 0;
        int rejectedPointCount = 0;
        bool matchExist = false;
        this->weightedPointUsedRatio = 0;
        
        for (int i = 0; i < requestedPts.features.cols(); ++i) //nb pts
        {
                matchExist = false;
                for(int k = 0; k < knn; k++) // knn
                {
                        const auto matchDist = matches.dists(k, i);
                        if (matchDist == Matches::InvalidDist){
                                continue;
                        }
 
                        if (outlierWeights(k,i) != 0.0)
                        {
                                if(dimReqDesc > 0)
                                        keptDesc.col(j) = requestedPts.descriptors.col(i);
 
                                if(dimReqTime > 0)
                                        keptTime.col(j) = requestedPts.times.col(i);
 
                                
                                keptFeat.col(j) = requestedPts.features.col(i);
                                keptMatches.ids(0, j) = matches.ids(k, i);
                                keptMatches.dists(0, j) = matchDist;
                                keptWeights(0,j) = outlierWeights(k,i);
                                ++j;
                                this->weightedPointUsedRatio += outlierWeights(k,i);
                                matchExist = true;
                        }
                        else
                        {
                                rejectedMatchCount++;
                        }
                }
 
                if(matchExist == false)
                {
                        rejectedPointCount++;
                }
        }
 
        assert(j == pointsCount);
 
        this->pointUsedRatio = T(j)/T(knn*requestedPts.features.cols());
        this->weightedPointUsedRatio /= T(knn*requestedPts.features.cols());
        
        assert(dimFeat == sourcePts.features.rows());
        const int dimSourDesc = sourcePts.descriptors.rows();
        const int dimSourTime = sourcePts.times.rows();
        
        Matrix associatedFeat(dimFeat, pointsCount);
        
        Matrix associatedDesc;
        if(dimSourDesc > 0)
                associatedDesc = Matrix(dimSourDesc, pointsCount);
        
        Int64Matrix associatedTime;
        if(dimSourTime> 0)
                associatedTime = Int64Matrix(dimSourTime, pointsCount);
        
        // Fetch matched points
        for (int i = 0; i < pointsCount; ++i)
        {
                const int refIndex(keptMatches.ids(i));
                associatedFeat.col(i) = sourcePts.features.block(0, refIndex, dimFeat, 1);
                
                if(dimSourDesc > 0)
                        associatedDesc.col(i) = sourcePts.descriptors.block(0, refIndex, dimSourDesc, 1);
 
                if(dimSourTime> 0)
                        associatedTime.col(i) = sourcePts.times.block(0, refIndex, dimSourTime, 1);
 
        }
 
        // Copy final data to structure
        this->reading = DataPoints(
                keptFeat, 
                requestedPts.featureLabels,
                keptDesc,
                requestedPts.descriptorLabels,
                keptTime,
                requestedPts.timeLabels
        );
 
        this->reference = DataPoints(
                associatedFeat,
                sourcePts.featureLabels,
                associatedDesc,
                sourcePts.descriptorLabels,
                associatedTime,
                sourcePts.timeLabels
        );
 
        this->weights = keptWeights;
        this->matches = keptMatches;
        this->nbRejectedMatches = rejectedMatchCount;
        this->nbRejectedPoints = rejectedPointCount;
}
 
 
// ErrorMinimizer
 
template<typename T>
PointMatcher<T>::ErrorMinimizer::ErrorMinimizer()
{}
 
template<typename T>
PointMatcher<T>::ErrorMinimizer::ErrorMinimizer(const std::string& className, const ParametersDoc paramsDoc, const Parameters& params):
        Parametrizable(className,paramsDoc,params)
{}
 
template<typename T>
PointMatcher<T>::ErrorMinimizer::~ErrorMinimizer()
{}
 
template<typename T>
typename PointMatcher<T>::TransformationParameters PointMatcher<T>::ErrorMinimizer::compute(const DataPoints& filteredReading, const DataPoints& filteredReference, const OutlierWeights& outlierWeights, const Matches& matches)
{
        
        // generates pairs of matching points
        typename ErrorMinimizer::ErrorElements matchedPoints(filteredReading, filteredReference, outlierWeights, matches);
        
        // calls specific instantiation for a given ErrorMinimizer
        TransformationParameters transform = this->compute(matchedPoints);
        
        // saves paired points for future introspection
        this->lastErrorElements = matchedPoints;
        
        // returns transforme parameters
        return transform;
}
 
template<typename T>
T PointMatcher<T>::ErrorMinimizer::getPointUsedRatio() const
{
        return lastErrorElements.pointUsedRatio;
}
 
template<typename T>
typename PointMatcher<T>::ErrorMinimizer::ErrorElements PointMatcher<T>::ErrorMinimizer::getErrorElements() const
{
        //Warning: the use of the variable lastErrorElements is not standardized yet.
        return lastErrorElements;
}
 
template<typename T>
T PointMatcher<T>::ErrorMinimizer::getWeightedPointUsedRatio() const
{
        return lastErrorElements.weightedPointUsedRatio;
}
 
template<typename T>
T PointMatcher<T>::ErrorMinimizer::getOverlap() const
{
        LOG_WARNING_STREAM("ErrorMinimizer - warning, no specific method to compute overlap was provided for the ErrorMinimizer used.");
        return lastErrorElements.weightedPointUsedRatio;
}
 
template<typename T>
typename PointMatcher<T>::Matrix PointMatcher<T>::ErrorMinimizer::getCovariance() const
{
        LOG_WARNING_STREAM("ErrorMinimizer - warning, no specific method to compute covariance was provided for the ErrorMinimizer used.");
        return Matrix::Zero(6,6);
}
 
template<typename T>
T PointMatcher<T>::ErrorMinimizer::getResidualError(const DataPoints& filteredReading, const DataPoints& filteredReference, const OutlierWeights& outlierWeights, const Matches& matches) const
{
        LOG_WARNING_STREAM("ErrorMinimizer - warning, no specific method to compute residual was provided for the ErrorMinimizer used.");
        return std::numeric_limits<T>::max();
}
 
template<typename T>
typename PointMatcher<T>::Matrix PointMatcher<T>::ErrorMinimizer::crossProduct(const Matrix& A, const Matrix& B)
{
        //Note: A = [x, y, z, 1] and B = [x, y, z] for convenience
 
        // Expecting matched points
        assert(A.cols() == B.cols());
 
        // Expecting homogenous coord X eucl. coord
        assert(A.rows() -1 == B.rows());
 
        // Expecting homogenous coordinates
        assert(A.rows() == 4 || A.rows() == 3);
        
        const unsigned int x = 0;
        const unsigned int y = 1;
        const unsigned int z = 2;
 
        Matrix cross;
        if(A.rows() == 4)
        {
                cross = Matrix(B.rows(), B.cols());
                                
                cross.row(x) = A.row(y).array() * B.row(z).array() - A.row(z).array() * B.row(y).array();
                cross.row(y) = A.row(z).array() * B.row(x).array() - A.row(x).array() * B.row(z).array();
                cross.row(z) = A.row(x).array() * B.row(y).array() - A.row(y).array() * B.row(x).array();
        }
        else
        {
                //pseudo-cross product for 2D vectors
                cross = Vector(B.cols());
                cross = A.row(x).array() * B.row(y).array() - A.row(y).array() * B.row(x).array();
        }
        return cross;
}
 
 
 
 
template struct PointMatcher<float>::ErrorMinimizer;
template struct PointMatcher<double>::ErrorMinimizer;