//
//  Filename         : ImagePyramid.h
//  Author(s)        : Stephane Grabli
//  Purpose          : Class to represent a pyramid of images
//  Date of creation : 25/12/2003
//
///////////////////////////////////////////////////////////////////////////////


//
//  Copyright (C) : Please refer to the COPYRIGHT file distributed 
//   with this source distribution. 
//
//  This program 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 2
//  of the License, or (at your option) any later version.
//
//  This program 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, write to the Free Software
//  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
//
///////////////////////////////////////////////////////////////////////////////

#ifndef  IMAGEPYRAMID_H
# define IMAGEPYRAMID_H

#include "../system/FreestyleConfig.h"
#include <vector>

class GrayImage;
class LIB_IMAGE_EXPORT ImagePyramid{
protected:
  std::vector<GrayImage*> _levels;
  
public:
  ImagePyramid(){}
  ImagePyramid(const ImagePyramid& iBrother);
  //ImagePyramid(const GrayImage& level0, unsigned nbLevels);
  virtual ~ImagePyramid();

  /*! Builds the pyramid.
   * must be overloaded by inherited classes.
   * if nbLevels==0, the complete pyramid is built
   */
  virtual void BuildPyramid(const GrayImage& level0, unsigned nbLevels) = 0;
  
  /*! Builds a pyramid without copying the base level */
  virtual void BuildPyramid(GrayImage* level0, unsigned nbLevels) = 0;
  
  virtual GrayImage * getLevel(int l);
  /*! Returns the pixel x,y using bilinear interpolation.
   *  \param x
   *    the abscissa specified in the finest level coordinate system
   *  \param y
   *    the ordinate specified in the finest level coordinate system
   *  \param level
   *    the level from which we want the pixel to be evaluated
   */
  virtual float pixel(int x, int y, int level=0);
  /*! Returns the width of the level-th level image */
  virtual int width(int level=0);
  /*! Returns the height of the level-th level image */
  virtual int height(int level=0);
  /*! Returns the number of levels in the pyramid */
  inline int getNumberOfLevels() const { return _levels.size();}
}; 

class LIB_IMAGE_EXPORT GaussianPyramid : public ImagePyramid
{
protected:
  float _sigma;
public:
  GaussianPyramid(float iSigma=1.f) : ImagePyramid() {_sigma=iSigma;}
  GaussianPyramid(const GrayImage& level0, unsigned nbLevels, float iSigma=1.f);
  GaussianPyramid(GrayImage* level0, unsigned nbLevels, float iSigma=1.f);
  GaussianPyramid(const GaussianPyramid& iBrother);
  virtual ~GaussianPyramid(){}

  virtual void BuildPyramid(const GrayImage& level0, unsigned nbLevels);
  virtual void BuildPyramid(GrayImage* level0, unsigned nbLevels);
  /* accessors */
  inline float getSigma() const {return _sigma;}
  /* modifiers */

};
#endif // IMAGEPYRAMID_H