include/filters/GP_Linear.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    Linear Convolution _Raw filters.
  26
  27  */
  28
  29 #ifndef FILTERS_GP_LINEAR_H
  30 #define FILTERS_GP_LINEAR_H
  31
  32 #include "GP_Filter.h"
  33
  34 /*
  35  * Linear convolution.
  36  *
  37  * The kernel is array of kw * kh floats and is indexed as two directional
  38  * array.
  39  *
  40  * The src coordinates and size defines rectangle in the source on which the
  41  * filter operates.
  42  *
  43  * The dst coodinates defines start pixel of in the destination context.
  44  *
  45  * To define 3x3 average filter
  46  *
  47  * kernel[] = {
  48  *      1, 1, 1,
  49  *      1, 1, 1,
  50  *      1, 1, 1,
  51  * };
  52  *
  53  * kw = kh = 3
  54  *
  55  * kern_div = 9
  56  *
  57  * This function works also in-place.
  58  */
  59 int GP_FilterLinearConvolution_Raw(const GP_Context *src,
  60                                    GP_Coord x_src, GP_Coord y_src,
  61                                    GP_Size w_src, GP_Size h_src,
  62                                    GP_Context *dst,
  63                                    GP_Coord x_dst, GP_Coord y_dst,
  64                                    float kernel[], uint32_t kw, uint32_t kh,
  65                                    float kern_div, GP_ProgressCallback *callback);
  66
  67 /*
  68  * Special cases for convolution only in horizontal/vertical direction.
  69  *
  70  * These are about 10-30% faster than the generic implementation (depending on
  71  * the kernel size, bigger kernel == more savings).
  72  *
  73  * These are two are a base for bilinear filters.
  74  *
  75  * Both works also in-place.
  76  */
  77 int GP_FilterHLinearConvolution_Raw(const GP_Context *src,
  78                                     GP_Coord x_src, GP_Coord y_src,
  79                                     GP_Size w_src, GP_Size h_src,
  80                                     GP_Context *dst,
  81                                     GP_Coord x_dst, GP_Coord y_dst,
  82                                     float kernel[], uint32_t kw, float kern_div,
  83                                     GP_ProgressCallback *callback);
  84
  85 int GP_FilterVLinearConvolution_Raw(const GP_Context *src,
  86                                     GP_Coord x_src, GP_Coord y_src,
  87                                     GP_Size w_src, GP_Size h_src,
  88                                     GP_Context *dst,
  89                                     GP_Coord x_dst, GP_Coord y_dst,
  90                                     float kernel[], uint32_t kh, float kern_div,
  91                                     GP_ProgressCallback *callback);
  92
  93 /*
  94  * Applies both horizontal and vertical convolution and takes care of the
  95  * correct progress callback (both horizontal and vertical kernels are expected
  96  * to be similar in size).
  97  */
  98 int GP_FilterVHLinearConvolution_Raw(const GP_Context *src,
  99                                      GP_Coord x_src, GP_Coord y_src,
 100                                      GP_Size w_src, GP_Size h_src,
 101                                      GP_Context *dst,
 102                                      GP_Coord x_dst, GP_Coord y_dst,
 103                                      float hkernel[], uint32_t kw, float hkern_div,
 104                                      float vkernel[], uint32_t kh, float vkern_div,
 105                                      GP_ProgressCallback *callback);
 106
 107 /*
 108  * Prints a kernel into the stdout.
 109  */
 110 void GP_FilterKernelPrint_Raw(float kernel[], int kw, int kh, float kern_div);
 111
 112 #endif /* FILTERS_GP_LINEAR_H */