gp_sigma.h

// SPDX-License-Identifier: LGPL-2.1-or-later
/*
 * Copyright (C) 2009-2012 Cyril Hrubis <metan@ucw.cz>
 */
 
 /*
 
   Sigma Lee filter.
 
   The xrad and yrad denotes radius the filter works on. The number of neighbor
   pixels is exactly 2 * rad + 1 for both directions.
 
   The sigma denotes maximal symetric difference of pixels scaled to [0,1]
   interval. Greater sigma causes results to be closer to mean linear filter.
 
   The min parameter defines minimial number of pixels that must be in the two
   sigma iterval, if there is a less pixels in this interval the new pixel
   value is computed as mean of the surrounding pixels (not including the
   center one).
 
  */
 
#ifndef FILTERS_GP_SIGMA_H
#define FILTERS_GP_SIGMA_H
 
#include <filters/gp_filter.h>
 
int gp_filter_sigma_ex(const gp_pixmap *src,
                       gp_coord x_src, gp_coord y_src,
                       gp_size w_src, gp_size h_src,
                       gp_pixmap *dst,
                       gp_coord x_dst, gp_coord y_dst,
                       int xrad, int yrad,
                       unsigned int min, float sigma,
                       gp_progress_cb *callback);
 
gp_pixmap *gp_filter_sigma_ex_alloc(const gp_pixmap *src,
                                    gp_coord x_src, gp_coord y_src,
                                    gp_size w_src, gp_size h_src,
                                    int xrad, int yrad,
                                    unsigned int min, float sigma,
                                    gp_progress_cb *callback);
 
static inline int gp_filter_sigma(const gp_pixmap *src,
                                  gp_pixmap *dst,
                                  int xrad, int yrad,
                                  unsigned int min, float sigma,
                                  gp_progress_cb *callback)
{
        return gp_filter_sigma_ex(src, 0, 0, src->w, src->h,
                                  dst, 0, 0, xrad, yrad, min, sigma, callback);
}
 
static inline gp_pixmap *gp_filter_sigma_alloc(const gp_pixmap *src,
                                               int xrad, int yrad,
                                               unsigned int min, float sigma,
                                               gp_progress_cb *callback)
{
        return gp_filter_sigma_ex_alloc(src, 0, 0, src->w, src->h,
                                        xrad, yrad, min, sigma, callback);
}
 
#endif /* FILTERS_GP_SIGMA_H */