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  * Gaussian blur
  36  *
  37  * The sigma parameters defines the blur radii in horizontal and vertical
  38  * direction.
  39  *
  40  * Internaly this is implemented as separable linear filter (calls vertical and
  41  * horizontal convolution with generated gaussian kernel).
  42  *
  43  * This variant could work in-place so it's perectly okay to call
  44  *
  45  * GP_FilterGaussianBlur_Raw(context, context, ...);
  46  */
  47 int GP_FilterGaussianBlur_Raw(const GP_Context *src, GP_Context *dst,
  48                               float sigma_x, float sigma_y,
  49                               GP_ProgressCallback *callback);
  50 /*
  51  * Gaussian blur.
  52  *
  53  * If dst is NULL, new bitmap is allocated.
  54  *
  55  * This variant could work in-place.
  56  *
  57  * Returns pointer to destination bitmap or NULL if allocation failed.
  58  */
  59 GP_Context *GP_FilterGaussianBlur(const GP_Context *src, GP_Context *dst,
  60                                   float sigma_x, float sigma_y,
  61                                   GP_ProgressCallback *callback);
  62
  63 /*
  64  * Linear convolution.
  65  *
  66  * The kernel is array of kw * kh floats and is indexed as two directional
  67  * array.
  68  *
  69  * The src coordinates and size defines rectangle in the source on which the
  70  * filter operates.
  71  *
  72  * The dst coodinates defines start pixel of in the destination context.
  73  *
  74  * To define 3x3 average filter
  75  *
  76  * kernel[] = {
  77  *      1, 1, 1,
  78  *      1, 1, 1,
  79  *      1, 1, 1,
  80  * };
  81  *
  82  * kw = kh = 3
  83  *
  84  * kern_div = 9
  85  *
  86  * This function works also in-place.
  87  */
  88 int GP_FilterLinearConvolution_Raw(const GP_Context *src,
  89                                    GP_Coord x_src, GP_Coord y_src,
  90                                    GP_Size w_src, GP_Size h_src,
  91                                    GP_Context *dst,
  92                                    GP_Coord x_dst, GP_Coord y_dst,
  93                                    float kernel[], uint32_t kw, uint32_t kh,
  94                                    float kern_div, GP_ProgressCallback *callback);
  95
  96 /*
  97  * Special cases for convolution only in horizontal/vertical direction.
  98  *
  99  * These are about 10-30% faster than the generic implementation (depending on
 100  * the kernel size, bigger kernel == more savings).
 101  *
 102  * These are two are a base for bilinear filters.
 103  *
 104  * Both works also in-place.
 105  */
 106 int GP_FilterHLinearConvolution_Raw(const GP_Context *src,
 107                                     GP_Coord x_src, GP_Coord y_src,
 108                                     GP_Size w_src, GP_Size h_src,
 109                                     GP_Context *dst,
 110                                     GP_Coord x_dst, GP_Coord y_dst,
 111                                     float kernel[], uint32_t kw, float kern_div,
 112                                     GP_ProgressCallback *callback);
 113
 114 int GP_FilterVLinearConvolution_Raw(const GP_Context *src,
 115                                     GP_Coord x_src, GP_Coord y_src,
 116                                     GP_Size w_src, GP_Size h_src,
 117                                     GP_Context *dst,
 118                                     GP_Coord x_dst, GP_Coord y_dst,
 119                                     float kernel[], uint32_t kh, float kern_div,
 120                                     GP_ProgressCallback *callback);
 121
 122 /*
 123  * Applies both horizontal and vertical convolution and takes care of the
 124  * correct progress callback (both horizontal and vertical kernels are expected
 125  * to be similar in size).
 126  */
 127 int GP_FilterVHLinearConvolution_Raw(const GP_Context *src,
 128                                      GP_Coord x_src, GP_Coord y_src,
 129                                      GP_Size w_src, GP_Size h_src,
 130                                      GP_Context *dst,
 131                                      GP_Coord x_dst, GP_Coord y_dst,
 132                                      float hkernel[], uint32_t kw, float hkern_div,
 133                                      float vkernel[], uint32_t kh, float vkern_div,
 134                                      GP_ProgressCallback *callback);
 135
 136 /*
 137  * Prints a kernel into the stdout.
 138  */
 139 void GP_FilterKernelPrint_Raw(float kernel[], int kw, int kh, float kern_div);
 140
 141 #endif /* FILTERS_GP_LINEAR_H */