include/filters/GP_Laplace.h

   1 /*****************************************************************************
   2  * This file is part of gfxprim library.                                     *
   3  *                                                                           *
   4  * Gfxprim is free software; you can redistribute it and/or                  *
   5  * modify it under the terms of the GNU Lesser General Public                *
   6  * License as published by the Free Software Foundation; either              *
   7  * version 2.1 of the License, or (at your option) any later version.        *
   8  *                                                                           *
   9  * Gfxprim is distributed in the hope that it will be useful,                *
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of            *
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU         *
  12  * Lesser General Public License for more details.                           *
  13  *                                                                           *
  14  * You should have received a copy of the GNU Lesser General Public          *
  15  * License along with gfxprim; if not, write to the Free Software            *
  16  * Foundation, Inc., 51 Franklin Street, Fifth Floor,                        *
  17  * Boston, MA  02110-1301  USA                                               *
  18  *                                                                           *
  19  * Copyright (C) 2009-2012 Cyril Hrubis <metan@ucw.cz>                       *
  20  *                                                                           *
  21  *****************************************************************************/
  22
  23 /*
  24
  25   Laplace filter and Laplace-based filters.
  26
  27  */
  28
  29 #ifndef FILTERS_GP_LAPLACE_H
  30 #define FILTERS_GP_LAPLACE_H
  31
  32 #include "GP_Filter.h"
  33
  34 /*
  35  * Discrete Laplace, second-derivative filter.
  36  *
  37  * Implemented by separable linear convolution with kernels
  38  *
  39  * [1 -2 1] and [ 1 ]
  40  *              [-2 ]
  41  *              [ 1 ]
  42  */
  43 int GP_FilterLaplace(const GP_Pixmap *src, GP_Pixmap *dst,
  44                      GP_ProgressCallback *callback);
  45
  46 GP_Pixmap *GP_FilterLaplaceAlloc(const GP_Pixmap *src,
  47                                   GP_ProgressCallback *callback);
  48
  49 /*
  50  * Laplace based filter sharpening.
  51  *
  52  * This filter substract result of Laplace filter weigted by w from the
  53  * original image which amplifies edges.
  54  */
  55 int GP_FilterEdgeSharpening(const GP_Pixmap *src, GP_Pixmap *dst,
  56                             float w, GP_ProgressCallback *callback);
  57
  58 GP_Pixmap *GP_FilterEdgeSharpeningAlloc(const GP_Pixmap *src, float w,
  59                                          GP_ProgressCallback *callback);
  60
  61 #endif /* FILTERS_GP_LAPLACE_H */