TextLineSegmentation.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 "BaseModule.h"
#include "Pixel.h"
#include "PixelSet.h"
#include "ScaleFactory.h"

#pragma warning(push, 0)    // no warnings from includes

#pragma warning(pop)

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

// Qt defines

namespace rdf {

// read defines

class DllCoreExport SimpleTextLineConfig : public ModuleConfig {

public:
    SimpleTextLineConfig(QSharedPointer<ScaleFactory> scaleFactory = QSharedPointer<ScaleFactory>(new ScaleFactory()));

    virtual QString toString() const override;

    void setMaxEdgeThresh(double et); // <-- hehe E.T.
    double maxEdgeTrhesh() const;
    
protected:

    double mMaxEdgeThresh = 20;         // maximum edge in px
    QSharedPointer<ScaleFactory> mScaleFactory;

    void load(const QSettings& settings) override;
    void save(QSettings& settings) const override;
};

class DllCoreExport SimpleTextLineSegmentation : public Module {

public:
    SimpleTextLineSegmentation(const PixelSet& set = PixelSet());

    bool isEmpty() const override;
    bool compute() override;

    cv::Mat draw(const cv::Mat& img, const QColor& col = QColor()) const;
    QString toString() const override;

    void addSeparatorLines(const QVector<Line>& lines);
    
    QVector<PixelSet> sets() const;
    QSharedPointer<SimpleTextLineConfig> config() const;
    QVector<QSharedPointer<TextLineSet> > textLineSets() const;

    // functions applied to the results
    void scale(double s);

private:
    PixelSet mSet;
    QVector<PixelSet> mTextLines;
    QVector<Line> mStopLines;

    // debug - delete!
    QVector<QSharedPointer<PixelEdge> > mEdges;

    bool checkInput() const override;
};


class DllCoreExport TextLineConfig : public ScaleModuleConfig {

public:
    TextLineConfig();

    virtual QString toString() const override;

    void setMinLineLength(int length);
    int minLineLength() const;

    void setMinPointDistance(double dist);
    double minPointDistance() const;

    void setErrorMultiplier(double multiplier);
    double errorMultiplier() const;

    QString debugPath() const;

protected:

    int mMinLineLength = 15;            // minimum text line length when clustering
    double mMinPointDist = 80.0;        // acceptable minimal distance of a point to a line
    double mErrorMultiplier = 1.4;      // maximal increase of error when merging two lines
    QString mDebugPath = "C:/temp/cluster/";    // TODO: remove

    void load(const QSettings& settings) override;
    void save(QSettings& settings) const override;
};

class DllCoreExport TextLineSegmentation : public Module {

public:
    TextLineSegmentation(const PixelSet& set = PixelSet());

    bool isEmpty() const override;
    bool compute() override;
    bool compute(const cv::Mat& img);
    QSharedPointer<TextLineConfig> config() const;

    void addSeparatorLines(const QVector<Line>& lines);
    QVector<QSharedPointer<TextLine> > textLines() const;
    QVector<QSharedPointer<TextLineSet> > textLineSets() const;

    // functions applied to the results
    void scale(double s);

    cv::Mat draw(const cv::Mat& img, const QColor& col = QColor()) const;
    static cv::Mat draw(const cv::Mat& img, const QVector<QSharedPointer<TextLineSet> >& textLines, const QColor& col = QColor());
    QString toString() const override;

private:
    PixelSet mSet;
    //QVector<QSharedPointer<PixelEdge> > mRemovedEdges;        // this is nice for debugging - but I would remove it in the end
    QVector<QSharedPointer<TextLineSet> > mTextLines;
    QVector<Line> mStopLines;

    bool checkInput() const override;

    QVector<QSharedPointer<TextLineSet> > clusterTextLines(const PixelGraph& graph, QVector<QSharedPointer<PixelEdge> >* removedEdges = 0) const;
    QVector<QSharedPointer<TextLineSet> > clusterTextLinesDebug(const PixelGraph& graph, const cv::Mat& img) const;
    int locate(const QSharedPointer<Pixel>& pixel, const QVector<QSharedPointer<TextLineSet> >& sets) const;
    bool addPixel(QSharedPointer<TextLineSet>& set, const QSharedPointer<Pixel>& pixel, double heat) const;
    bool mergeTextLines(const QSharedPointer<TextLineSet>& tln1, const QSharedPointer<TextLineSet>& tln2, double heat) const;
    void filterDuplicates(PixelSet& set) const;

    // post processing
    void mergeUnstableTextLines(QVector<QSharedPointer<TextLineSet> >& textLines) const;
};

}