root/modules/shape/src/haus_dis.cpp

DEFINITIONS

1. setDistanceFlag
2. getDistanceFlag
3. setRankProportion
4. getRankProportion
5. write
6. read
7. _apply
8. computeDistance
9. createHausdorffDistanceExtractor

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#include "precomp.hpp"

namespace cv
{

class HausdorffDistanceExtractorImpl : public HausdorffDistanceExtractor
{
public:
    /* Constructor */
    HausdorffDistanceExtractorImpl(int _distanceFlag = NORM_L1, float _rankProportion=0.6)
    {
        distanceFlag = _distanceFlag;
        rankProportion = _rankProportion;
        name_ = "ShapeDistanceExtractor.HAU";
    }

    /* Destructor */
    ~HausdorffDistanceExtractorImpl()
    {
    }

    //! the main operator
    virtual float computeDistance(InputArray contour1, InputArray contour2);

    //! Setters/Getters
    virtual void setDistanceFlag(int _distanceFlag) {distanceFlag=_distanceFlag;}
    virtual int getDistanceFlag() const {return distanceFlag;}

    virtual void setRankProportion(float _rankProportion)
    {
        CV_Assert((_rankProportion>0) && (_rankProportion<=1));
        rankProportion=_rankProportion;
    }
    virtual float getRankProportion() const {return rankProportion;}

    //! write/read
    virtual void write(FileStorage& fs) const
    {
        fs << "name" << name_
           << "distance" << distanceFlag
           << "rank" << rankProportion;
    }

    virtual void read(const FileNode& fn)
    {
        CV_Assert( (String)fn["name"] == name_ );
        distanceFlag = (int)fn["distance"];
        rankProportion = (float)fn["rank"];
    }

private:
    int distanceFlag;
    float rankProportion;

protected:
    String name_;
};

//! Hausdorff distance for a pair of set of points
static float _apply(const Mat &set1, const Mat &set2, int distType, double propRank)
{
    // Building distance matrix //
    Mat disMat(set1.cols, set2.cols, CV_32F);
    int K = int(propRank*(disMat.rows-1));

    for (int r=0; r<disMat.rows; r++)
    {
        for (int c=0; c<disMat.cols; c++)
        {
            Point2f diff = set1.at<Point2f>(0,r)-set2.at<Point2f>(0,c);
            disMat.at<float>(r,c) = (float)norm(Mat(diff), distType);
        }
    }

    Mat shortest(disMat.rows,1,CV_32F);
    for (int ii=0; ii<disMat.rows; ii++)
    {
        Mat therow = disMat.row(ii);
        double mindis;
        minMaxIdx(therow, &mindis);
        shortest.at<float>(ii,0) = float(mindis);
    }
    Mat sorted;
    cv::sort(shortest, sorted, SORT_EVERY_ROW | SORT_DESCENDING);
    return sorted.at<float>(K,0);
}

float HausdorffDistanceExtractorImpl::computeDistance(InputArray contour1, InputArray contour2)
{
    Mat set1=contour1.getMat(), set2=contour2.getMat();
    if (set1.type() != CV_32F)
        set1.convertTo(set1, CV_32F);
    if (set2.type() != CV_32F)
        set2.convertTo(set2, CV_32F);
    CV_Assert((set1.channels()==2) && (set1.cols>0));
    CV_Assert((set2.channels()==2) && (set2.cols>0));
    return std::max( _apply(set1, set2, distanceFlag, rankProportion),
                     _apply(set2, set1, distanceFlag, rankProportion) );
}

Ptr <HausdorffDistanceExtractor> createHausdorffDistanceExtractor(int distanceFlag, float rankProp)
{
    return Ptr<HausdorffDistanceExtractor>(new HausdorffDistanceExtractorImpl(distanceFlag, rankProp));
}

} // cv