LabeledSkeletonImage.H

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/*---------------------------------------------------------------------+
 | Library QgarLib, graphics analysis and recognition                  |
 | Copyright (C) 2002  Qgar Project, LORIA                             |
 |                                                                     |
 | This library is free software; you can redistribute it and/or       |
 | modify it under the terms of the GNU Lesser General Public          |
 | License version 2.1, as published by the Free Software Foundation.  |
 |                                                                     |
 | This library 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 Lesser General Public License for more details.         |
 |                                                                     |
 | The GNU Lesser General Public License is included in the file       |
 | LICENSE.LGPL, in the root directory of the Qgar packaging. See      |
 | http://www.gnu.org/licenses/lgpl.html for the terms of the licence. |
 | To receive a paper copy, write to the Free Software Foundation,     |
 | Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.       |
 |                                                                     |
 | Contact Project Qgar for any information:                           |
 |   LORIA - équipe Qgar                                               |
 |   B.P. 239, 54506 Vandoeuvre-lès-Nancy Cedex, France                |
 |   email: qgar-contact@loria.fr                                      |
 |   http://www.qgar.org/                                              |
 *---------------------------------------------------------------------*/


#ifndef __LABELEDSKELETONIMAGE_H_INCLUDED__
#define __LABELEDSKELETONIMAGE_H_INCLUDED__


/**
 * @file   LabeledSkeletonImage.H
 * @brief  Header file of class qgar::LabeledSkeletonImage.
 *
 * @author <a href="mailto:qgar-develop@loria.fr?subject=Qgar fwd Karl Tombre">Adlane Habed and Karl Tombre</a>
 * @date   July 3,  2001  16:46
 * @since  Qgar 1.0
 */


// For RCS/CVS use: Do not delete
/* $Id: LabeledSkeletonImage.H,v 1.23 2005/10/14 17:05:47 masini Exp $ */



// STD
#include <vector>
// QGAR
#include <qgarlib/GenImage.H>
namespace qgar
{
  // Avoid #include's when not necessary
  class Dist34BlackCCImage;
  template <class T> class GenPoint;
}



namespace qgar
{


/** 
 * @ingroup IMGPROC_SKEL
 *
 * @class LabeledSkeletonImage LabeledSkeletonImage.H "qgarlib/LabeledSkeletonImage.H"
 *
 * @brief Skeleton computed using the (3,4)-distance transform.
 *
 * As described by Gabriella Sanniti di Baja in
 * [<a href="Bibliography.html#Sanniti-di-Baja-1994">Sanniti&nbsp;di&nbsp;Baja,&nbsp;1994</a>]
 */
class LabeledSkeletonImage

  : public GreyLevelImage

{
// -------------------------------------------------------------------
// P U B L I C    M E M B E R S
// -------------------------------------------------------------------
public:

  /** @name Constructors */
  //        ============
  //@{

  /**
   * @brief Construct from given (3,4)-distance transform image.
   *
   * @param img   3-4 distance transform image
   *   from which the skeleton is created
   * @param maxPruning maximum number of peripheral rows and/or columns
   *   which may be missed (default <b>0</b>, no pruning)
   */
  LabeledSkeletonImage(const Dist34BlackCCImage& img, int maxPruning = 0);

  //@}


  /** @name Destructor */
  //        ==========
  //@{

  /**
   * @brief Virtual destructor.
   */
  virtual ~LabeledSkeletonImage();

  //@}

// -------------------------------------------------------------------
// P R O T E C T E D    M E M B E R S
// -------------------------------------------------------------------
protected:

  /** @name The skeleton image */
  //        ==================
  //@{

  /**
   * @brief The marker map.
   */
  unsigned char* _pixMap2;

  //@}

// -------------------------------------------------------------------
// P R I V A T E    M E M B E R S
// -------------------------------------------------------------------
private:

  //  ================================================================
  /** @name Auxiliaries
    In all subsequent labellings, neighbors are numbered as following:
@verbatim
  2 3 4
  1 0 5
  8 7 6
@endverbatim
    */
  //  ================================================================
  //@{

  /**
   * @brief Find parallelwise detectable skeletal pixels.
   */
  void parallelSkelet();

  /**
   * @brief Find sequentially detectable skeletal pixels.
   */
  void sequentSkelet();

  /**
   * @brief Hole filling and final thinning.
   */
  void finalThinning();

  /**
   * @brief Pruning.
   */
  void pruning(std::vector< GenPoint<int> >& myEndPoints,
               int maxPruning);

  /**
   * @brief Remove jaggedness.
   */
  void removeJaggedness();

  /**
   * @brief Load the right labels for a neighborhood.
   */
  void loadLabeledNeighbors(unsigned char* p, unsigned char* n);

  /**
   * @brief Load the binary image of a neighborhood.
   */
  void loadBinaryNeighbors(unsigned char* p, unsigned char* n);

  /**
   * @brief Load suitable X binary neighbors.
   */
  void loadSuitXBinary(unsigned char suitbin[], unsigned char n[]);

  /**
   * @brief Load suitable C binary neighbors.
   */
  void loadSuitCBinary(unsigned char suitbin[], unsigned char n[]);

  /**
   * @brief Number of 8-connected components in a neighborhood.
   */
  int connexityCnt(unsigned char n[]);

  /**
   * @brief Number of 4-connected components in a neighborhood.
   */
  int crossingCnt(unsigned char n[]);

  /**
   * @brief Degree of a point: Its number of marked neighbors.
   */
  int degree(unsigned char* p);

  /**
   * @brief Triple consecutive neighbors all labeled 3
   * (after changes all labeled 1).
   */
  int oddEvenOddLab3(unsigned char n[], int debut);

  /**
   * @brief Gradient in a 3x3 neighborhood.
   */
  void gradient(unsigned char n[], float grad[]);

  /**
   * @brief Position of maximum gradient.
   */
  int maxGradientPos1(unsigned char* p, float grad[]);

  /**
   * @brief Find, if any, second position with same maximum gradient.
   */
  int maxGradientPos2(float grad[], unsigned char* p, int indmax);

  /**
   * @brief Reduce to unit width.
   *
   * Erase marker from any marked pixel satisfying both:
   * - at least one odd-neighbor is not marked,
   * - at least a triplet of neighbors <b>(nk, nk+2, nk+5)</b>
   *   (<b>k</b> odd, addition modulo 8) exists such that
   *   <b>nk</b> and <b>nk+2</b> are marked, and <b>nk+5</b>
   *   is not marked.
   */
  void unitWidth(unsigned char* p, unsigned char lab[]);

  //@}

// -------------------------------------------------------------------
}; // class LabeledSkeletonImage


} // namespace qgar


#endif /* __LABELEDSKELETONIMAGE_H_INCLUDED__ */