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/*
* ***** BEGIN GPL LICENSE BLOCK *****
*
* 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* ***** END GPL LICENSE BLOCK *****
*/
#ifndef __GAUSSIANFILTER_H__
#define __GAUSSIANFILTER_H__
/** \file blender/freestyle/intern/image/GaussianFilter.h
* \ingroup freestyle
* \brief Class to perform gaussian filtering operations on an image
* \author Stephane Grabli
* \date 20/05/2003
*/
#include <cstdlib> // for abs
#include <string.h> // for memcpy
#include "../system/FreestyleConfig.h"
extern "C" {
#include "BLI_math.h"
}
#ifdef WITH_CXX_GUARDEDALLOC
#include "MEM_guardedalloc.h"
#endif
namespace Freestyle {
class LIB_IMAGE_EXPORT GaussianFilter
{
protected:
/* The mask is a symetrical 2d array (with respect to the middle point).
* Thus, M(i,j) = M(-i,j) = M(i,-j) = M(-i,-j).
* For this reason, to represent a NxN array (N odd), we only store a ((N+1)/2)x((N+1)/2) array.
*/
float _sigma;
float *_mask;
int _bound;
// the real mask size (must be odd)(the size of the mask we store is ((_maskSize+1)/2)*((_maskSize+1)/2))
int _maskSize;
int _storedMaskSize; // (_maskSize+1)/2)
public:
GaussianFilter(float iSigma = 1.0f);
GaussianFilter(const GaussianFilter&);
GaussianFilter& operator=(const GaussianFilter&);
virtual ~GaussianFilter();
/*! Returns the value for pixel x,y of image "map" after a gaussian blur, made using the sigma value.
* The sigma value determines the mask size (~ 2 x sigma).
* \param map
* The image we wish to work on. The Map template must implement the following methods:
* - float pixel(unsigned int x,unsigned int y) const;
* - unsigned width() const;
* - unsigned height() const;
* \param x
* The abscissa of the pixel where we want to evaluate the gaussian blur.
* \param y
* The ordinate of the pixel where we want to evaluate the gaussian blur.
* \param sigma
* The sigma value of the gaussian function.
*/
template<class Map>
float getSmoothedPixel(Map *map, int x, int y);
/*! Compute the mask size and returns the REAL mask size ((2*_maskSize)-1)
* This method is provided for convenience.
*/
static int computeMaskSize(float sigma);
/*! accessors */
inline float sigma() const
{
return _sigma;
}
inline int maskSize() const
{
return _maskSize;
}
inline int getBound()
{
return _bound;
}
/*! modifiers */
void setSigma(float sigma);
#if 0
void SetMaskSize(int size)
{
_maskSize = size;
_storedMaskSize = (_maskSize + 1) >> 1;
}
#endif
protected:
void computeMask();
#ifdef WITH_CXX_GUARDEDALLOC
MEM_CXX_CLASS_ALLOC_FUNCS("Freestyle:GaussianFilter")
#endif
};
/*
#############################################
#############################################
#############################################
###### ######
###### I M P L E M E N T A T I O N ######
###### ######
#############################################
#############################################
#############################################
*/
template<class Map>
float GaussianFilter::getSmoothedPixel(Map *map, int x, int y)
{
float sum = 0.0f;
float L = 0.0f;
int w = (int)map->width(); //soc
int h = (int)map->height(); //soc
// Current pixel is x,y
// Sum surrounding pixels L value:
for (int i = -_bound; i <= _bound; ++i) {
if ((y + i < 0) || (y + i >= h))
continue;
for (int j = -_bound; j <= _bound; ++j) {
if ((x + j < 0) || (x + j >= w))
continue;
float tmpL = map->pixel(x + j, y + i);
float m = _mask[abs(i) * _storedMaskSize + abs(j)];
L += m * tmpL;
sum += m;
}
}
//L /= sum;
return L;
}
} /* namespace Freestyle */
#endif // __GAUSSIANFILTER_H__
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