PixelSet.h

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/*******************************************************************************************************
 ReadFramework is the basis for modules developed at CVL/TU Wien for the EU project READ. 
  
 Copyright (C) 2016 Markus Diem <diem@caa.tuwien.ac.at>
 Copyright (C) 2016 Stefan Fiel <fiel@caa.tuwien.ac.at>
 Copyright (C) 2016 Florian Kleber <kleber@caa.tuwien.ac.at>

 This file is part of ReadFramework.

 ReadFramework is free software: you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
 the Free Software Foundation, either version 3 of the License, or
 (at your option) any later version.

 ReadFramework is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU General Public License for more details.

 You should have received a copy of the GNU General Public License
 along with this program.  If not, see <http://www.gnu.org/licenses/>.

 The READ project  has  received  funding  from  the European  Union’s  Horizon  2020  
 research  and innovation programme under grant agreement No 674943
 
 related links:
 [1] http://www.caa.tuwien.ac.at/cvl/
 [2] https://transkribus.eu/Transkribus/
 [3] https://github.com/TUWien/
 [4] http://nomacs.org
 *******************************************************************************************************/

#pragma once

#include "Shapes.h"
#include "BaseImageElement.h"
#include "Pixel.h"
#include "Algorithms.h"

#pragma warning(push, 0)    // no warnings from includes
#include <QObject>
#include <QSharedPointer>
#include <QVector>
#include <QMap>
#pragma warning(pop)

#ifndef DllCoreExport
#ifdef DLL_CORE_EXPORT
#define DllCoreExport Q_DECL_EXPORT
#else
#define DllCoreExport Q_DECL_IMPORT
#endif
#endif

// Qt defines
class QPainter;

namespace rdf {

// elements
class TextLine;
class PixelSet;

class DllCoreExport PixelConnector {

public:
    PixelConnector();
    
    virtual QVector<QSharedPointer<PixelEdge> > connect(const QVector<QSharedPointer<Pixel> >& pixels) const = 0;
    void setDistanceFunction(const PixelDistance::PixelDistanceFunction& distFnc);
    void setStopLines(const QVector<Line>& stopLines);

protected:
    PixelDistance::PixelDistanceFunction mDistanceFnc;
    QVector<Line> mStopLines;

    QVector<QSharedPointer<PixelEdge> > filter(QVector<QSharedPointer<PixelEdge> >& edges) const;
};

class DllCoreExport DelaunayPixelConnector : public PixelConnector {

public:
    DelaunayPixelConnector();
    virtual QVector<QSharedPointer<PixelEdge> > connect(const QVector<QSharedPointer<Pixel> >& pixels) const override;
};

class DllCoreExport VoronoiPixelConnector : public PixelConnector {

public:
    VoronoiPixelConnector();
    virtual QVector<QSharedPointer<PixelEdge> > connect(const QVector<QSharedPointer<Pixel> >& pixels) const override;
};


class DllCoreExport RegionPixelConnector : public PixelConnector {

public:
    RegionPixelConnector(double multiplier = 2.0);

    virtual QVector<QSharedPointer<PixelEdge> > connect(const QVector<QSharedPointer<Pixel> >& pixels) const override;

    void setRadius(double radius);
    void setLineSpacingMultiplier(double multiplier);

protected:
    double mRadius = 0.0;
    double mMultiplier = 2.0;
};

class DllCoreExport TabStopPixelConnector : public PixelConnector {

public:
    TabStopPixelConnector();

    virtual QVector<QSharedPointer<PixelEdge> > connect(const QVector<QSharedPointer<Pixel> >& pixels) const override;

    void setLineSpacingMultiplier(double multiplier);

protected:
    double mMultiplier = 1.0;

};

class DllCoreExport DBScanPixelConnector : public PixelConnector {

public:
    DBScanPixelConnector();

    virtual QVector<QSharedPointer<PixelEdge> > connect(const QVector<QSharedPointer<Pixel> >& pixels) const override;

protected:
    double mEpsMultiplier = 1.2;

};

class DllCoreExport PixelSet : public BaseElement {

public:
    PixelSet();
    PixelSet(const QVector<QSharedPointer<Pixel> >& set);

    enum ConnectionMode {
        connect_Delaunay,
        connect_region,

        connect_end
    };

    enum mDrawFlags {
        draw_nothing    = 0x0,
        draw_pixels     = 0x1,
        draw_poly       = 0x2,
        draw_rect       = 0x4,

        draw_end
    };
    typedef Flags<mDrawFlags> DrawFlags;

    void operator+=(const PixelSet& set);

    QSharedPointer<Pixel> operator[](int idx) const;
    void operator<<(const QSharedPointer<Pixel>& pixel);
    void operator<<(const PixelSet& set);

    bool isEmpty() const;
    bool contains(const QSharedPointer<Pixel>& pixel) const;
    
    // functions that change the set
    virtual void add(const QSharedPointer<Pixel>& pixel);
    virtual void remove(const QSharedPointer<Pixel>& pixel);
    virtual void append(const QVector<QSharedPointer<Pixel> >& set);
    virtual void scale(double factor);
    virtual void filterDuplicates(int eps = 5);

    QVector<QSharedPointer<Pixel> > pixels() const {
        return mSet;
    };

    int size() const;
    QVector<Vector2D> pointSet(double offsetAngle = 0.0) const;
    QVector<Vector2D> centers() const;
    Polygon convexHull() const;
    Rect boundingBox() const;
    Line fitLine(double offsetAngle = 0.0) const;
    Ellipse fitEllipse() const;

    Vector2D center() const;
    Vector2D meanCenter() const;
    double orientation(double statMoment = 0.5) const;
    double lineSpacing(double statMoment = 0.5) const;
    double area() const;

    QSharedPointer<Pixel> find(const QString& id) const;

    QSharedPointer<TextLine> toTextLine() const;

    virtual void draw(
        QPainter& p, 
        const DrawFlags& options = DrawFlags() | draw_pixels | draw_poly,
        const Pixel::DrawFlags& pixelOptions = Pixel::DrawFlags() | Pixel::draw_ellipse | Pixel::draw_label_colors) const;

    static QVector<QSharedPointer<PixelEdge> > connect(const QVector<QSharedPointer<Pixel> >& superPixels, const ConnectionMode& mode = connect_Delaunay);
    static QVector<PixelSet> fromEdges(const QVector<QSharedPointer<PixelEdge> >& edges);
    static PixelSet merge(const QVector<PixelSet>& sets);
    QVector<PixelSet> splitScales() const;

    virtual QString toString() const override;

protected:
    QVector<QSharedPointer<Pixel> > mSet;

    Polygon polygon(const QVector<Vector2D>& pts) const;
};

class DllCoreExport TextLineSet : public PixelSet {

public:
    TextLineSet();
    TextLineSet(const QVector<QSharedPointer<Pixel> >& set);

    // functions that change the set
    void add(const QSharedPointer<Pixel>& pixel) override;
    void remove(const QSharedPointer<Pixel>& pixel) override;
    void append(const QVector<QSharedPointer<Pixel> >& set) override;
    void scale(double factor) override;
    void update();

    void draw(QPainter& p, const DrawFlags& options = PixelSet::draw_poly, 
        const Pixel::DrawFlags& pixelOptions = Pixel::draw_ellipse) const override;

    Line line() const;
    double error() const;
    double computeError(const QVector<Vector2D>& pts) const;
    double density() const;

protected:
    Line mLine;
    double mLineErr = DBL_MAX;

    void updateLine();
};

namespace TextLineHelper {

    QVector<QSharedPointer<TextLineSet> > filterLowDensity(const QVector<QSharedPointer<TextLineSet> >& textLines);
    QVector<QSharedPointer<TextLineSet> > filterHeight(const QVector<QSharedPointer<TextLineSet> >& textLines, double minHeight = 5, double maxHeight = 5000);
    QVector<QSharedPointer<TextLineSet> > filterAngle(const QVector<QSharedPointer<TextLineSet> >& textLines, double maxAngle = 4 * DK_DEG2RAD);

    void mergeStableTextLines(QVector<QSharedPointer<TextLineSet> >& textLines);

    QSharedPointer<TextLineSet> find(const QString& id, const QVector<QSharedPointer<TextLineSet> >& tl);
    bool merge(const QSharedPointer<TextLineSet> & tl1, const QSharedPointer<TextLineSet> & tl2);

}

class DllCoreExport TextBlock : public BaseElement {

public:
    TextBlock(const Polygon& poly = Polygon(), const QString& id = "");

    enum mDrawFlags {
        draw_nothing = 0x0,
        draw_poly = 0x1,
        draw_text_lines = 0x2,
        draw_pixels = 0x4,

        draw_end
    };

    typedef Flags<mDrawFlags> DrawFlags;

    void addPixels(const PixelSet& ps);
    PixelSet pixelSet() const;

    void scale(double factor) override;

    Polygon poly() const;

    void setTextLines(const QVector<QSharedPointer<TextLineSet> >& textLines);
    QVector<QSharedPointer<TextLineSet> > textLines() const;
    bool remove(const QSharedPointer<TextLineSet>& tl);
    void cleanTextLines();

    QSharedPointer<Region> toTextRegion() const;

    void draw(QPainter& p, const DrawFlags& df = DrawFlags() | draw_poly | draw_text_lines);
    virtual QString toString() const override;

private:
    Polygon mPoly;
    PixelSet mSet;
    QVector<QSharedPointer<TextLineSet> > mTextLines;
};

class DllCoreExport TextBlockSet : public BaseElement {

public:
    TextBlockSet(const QVector<Polygon>& regions = QVector<Polygon>());
    TextBlockSet(const QVector<QSharedPointer<Region>>& regions);

    void operator<<(const TextBlock& block);

    bool isEmpty() const;

    void scale(double factor) override;

    void setPixels(const PixelSet& ps);
    QVector<QSharedPointer<TextBlock> > textBlocks() const;

    QSharedPointer<Region> toTextRegion() const;

    void removeWeakTextLines() const;

private:
    
    QVector<QSharedPointer<TextBlock> > mTextBlocks;
};


class DllCoreExport PixelGraph : public BaseElement {

public:
    PixelGraph();
    PixelGraph(const PixelSet& set);

    enum SortMode {
        sort_none,
        sort_edges,
        sort_line_edges,
        sort_distance,  // euclidean

        sort_end
    };

    bool isEmpty() const;

    void draw(QPainter& p, const PixelDistance::EdgeWeightFunction* weightFnc = 0, double dynamicRange = 1.0) const;
    void connect(const PixelConnector& connector = DelaunayPixelConnector(), const SortMode& sort = sort_none);

    PixelSet set() const;
    QVector<QSharedPointer<PixelEdge> > edges(const QString& pixelID) const;
    QVector<QSharedPointer<PixelEdge> > edges(const QVector<int>& edgeIDs) const;
    QVector<QSharedPointer<PixelEdge> > edges() const;

    int pixelIndex(const QString & pixelID) const;
    QVector<int> edgeIndexes(const QString & pixelID) const;

protected:
    PixelSet mSet;
    QVector<QSharedPointer<PixelEdge> > mEdges;

    QMap<QString, int> mPixelLookup;            // maps pixel IDs to their current vector index
    QMap<QString, QVector<int> > mPixelEdges;   // maps pixel IDs to their corresponding edge index

};

class DllCoreExport DBScanPixel {

public:
    DBScanPixel(const PixelSet& pixels);

    void compute();

    void setMaxDistance(double dist);
    void setEpsilonMultiplier(double eps);
    void setDistanceFunction(const PixelDistance::PixelDistanceFunction& distFnc);
    void setFast(bool f);

    QVector<PixelSet> sets() const;
    QVector<QSharedPointer<PixelEdge> > edges() const;

protected:
    PixelSet mPixels;       // input


    enum Label {
        not_visited = 0,
        visited,
        noise, 

        cluster0
    };

    // cache
    cv::Mat mDists;
    cv::Mat mLabels;
    unsigned int* mLabelPtr;

    unsigned int mCLabel = cluster0;

    // parameters
    PixelDistance::PixelDistanceFunction mDistFnc = &PixelDistance::euclidean;
    double mMaxDistance = 0;
    double mEpsMultiplier = 2.0;
    int mMinPts = 3;
    bool mFast = false;

    void expandCluster(int pixelIndex, unsigned int clusterIndex, const QVector<int>& neighbors, double eps, int minPts) const;
    QVector<int> regionQuery(int pixelIdx, double eps) const;

    cv::Mat calcDists(const PixelSet& pixels) const;
};

}