wrlib/convolve.c

   1 /*
   2  * Raster graphics library
   3  *
   4  * Copyright (c) 1997-2003 Alfredo K. Kojima
   5  *
   6  *  This library is free software; you can redistribute it and/or
   7  *  modify it under the terms of the GNU Library General Public
   8  *  License as published by the Free Software Foundation; either
   9  *  version 2 of the License, or (at your option) any later version.
  10  *
  11  *  This library is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  *  Library General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU Library General Public
  17  *  License along with this library; if not, write to the Free
  18  *  Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  19  */
  20
  21 #include <config.h>
  22
  23
  24 #include <stdlib.h>
  25 #include <stdio.h>
  26 #include <string.h>
  27 #include <X11/Xlib.h>
  28 #include "wraster.h"
  29
  30
  31 /*
  32  *----------------------------------------------------------------------
  33  * RBlurImage--
  34  *      Apply 3x3 1 1 1 low pass, convolution mask to image.
  35  *                1 2 1
  36  *                1 1 1 /10
  37  *----------------------------------------------------------------------
  38  */
  39 int
  40 RBlurImage(RImage *image)
  41 {
  42     register int x, y;
  43     register int tmp;
  44     unsigned char *ptr, *nptr;
  45     unsigned char *pptr=NULL, *tmpp;
  46     int ch = image->format == RRGBAFormat ? 4 : 3;
  47
  48     pptr = malloc(image->width * ch);
  49     if (!pptr) {
  50         RErrorCode = RERR_NOMEMORY;
  51         return False;
  52     }
  53
  54 #define MASK(prev, cur, next, ch)\
  55     (*(prev-ch) + *prev + *(prev+ch)\
  56     +*(cur-ch) + 2 * *cur + *(cur+ch)\
  57     +*(next-ch) + *next + *(next+ch)) / 10
  58
  59     memcpy(pptr, image->data, image->width * ch);
  60
  61     ptr = image->data;
  62     nptr = ptr + image->width*ch;
  63     tmpp = pptr;
  64
  65     if (ch == 3) {
  66         ptr+=3;
  67         nptr+=3;
  68         pptr+=3;
  69
  70         for (y = 1; y < image->height-1; y++) {
  71
  72             for (x = 1; x < image->width-1; x++) {
  73                 tmp = *ptr;
  74                 *ptr = MASK(pptr, ptr, nptr, 3);
  75                 *pptr = tmp;
  76                 ptr++; nptr++; pptr++;
  77
  78                 tmp = *ptr;
  79                 *ptr = MASK(pptr, ptr, nptr, 3);
  80                 *pptr = tmp;
  81                 ptr++; nptr++; pptr++;
  82
  83                 tmp = *ptr;
  84                 *ptr = MASK(pptr, ptr, nptr, 3);
  85                 *pptr = tmp;
  86                 ptr++; nptr++; pptr++;
  87             }
  88             pptr = tmpp;
  89             ptr+=6;
  90             nptr+=6;
  91             pptr+=6;
  92         }
  93     } else {
  94         ptr+=4;
  95         nptr+=4;
  96         pptr+=4;
  97
  98         for (y = 1; y < image->height-1; y++) {
  99             for (x = 1; x < image->width-1; x++) {
 100                 tmp = *ptr;
 101                 *ptr = MASK(pptr, ptr, nptr, 4);
 102                 *pptr = tmp;
 103                 ptr++; nptr++; pptr++;
 104
 105                 tmp = *ptr;
 106                 *ptr = MASK(pptr, ptr, nptr, 4);
 107                 *pptr = tmp;
 108                 ptr++; nptr++; pptr++;
 109
 110                 tmp = *ptr;
 111                 *ptr = MASK(pptr, ptr, nptr, 4);
 112                 *pptr = tmp;
 113                 ptr++; nptr++; pptr++;
 114
 115                 tmp = *ptr;
 116                 *ptr = MASK(pptr, ptr, nptr, 4);
 117                 *pptr = tmp;
 118                 ptr++; nptr++; pptr++;
 119             }
 120             pptr = tmpp;
 121             ptr+=8;
 122             nptr+=8;
 123             pptr+=8;
 124         }
 125     }
 126
 127
 128     return True;
 129 }
 130
 131
 132 #if 0
 133 int
 134 REdgeDetectImage(RImage *image)
 135 {
 136     register int x, y, d1, d2, d3, d4, rsum;
 137     int w;
 138     unsigned char *r, *g, *b, *a;
 139     unsigned char *dr, *dg, *db, *da;
 140     unsigned char *pr=NULL, *pg=NULL, *pb=NULL, *pa=NULL;
 141     RImage *image2;
 142
 143
 144     image2 = RCloneImage(image);
 145
 146     pr = alloca(image->width*sizeof(char));
 147     if (!pr)
 148         goto outofmem;
 149
 150     pg = alloca(image->width*sizeof(char));
 151     if (!pg)
 152         goto outofmem;
 153
 154     pb = alloca(image->width*sizeof(char));
 155     if (!pb)
 156         goto outofmem;
 157
 158     pa = alloca(image->width*sizeof(char));
 159     if (!pa)
 160         goto outofmem;
 161
 162
 163     r = image->data[0];
 164     g = image->data[1];
 165     b = image->data[2];
 166     a = image->data[3];
 167
 168     dr = image2->data[0];
 169     dg = image2->data[1];
 170     db = image2->data[2];
 171     da = image2->data[3];
 172
 173
 174     for (x=0; x<image->width; x++) {
 175         *(dr++) = *(r++);
 176         *(dg++) = *(g++);
 177         *(db++) = *(b++);
 178     }
 179
 180     w = image->width;
 181
 182     for (y=1; y<image->height-1; y++) {
 183         dr[w-1] = r[w-1];
 184         dg[w-1] = g[w-1];
 185         db[w-1] = b[w-1];
 186
 187         *(dr++) = *(r++);
 188         *(dg++) = *(g++);
 189         *(db++) = *(b++);
 190
 191         for (x=1; x<image->width-1; x++) {
 192             d1 = r[w+1]  - r[-w-1];
 193             d2 = r[1]    - r[-1];
 194             d3 = r[-w+1] - r[w-1];
 195             d4 = r[-w]   - r[w];
 196
 197             rsum = d1 + d2 + d3;
 198             if (rsum < 0) rsum = -rsum;
 199             d1 = d1 - d2 - d4;         /* vertical gradient */
 200             if (d1 < 0) d1 = -d1;
 201             if (d1 > rsum) rsum = d1;
 202             rsum /= 3;
 203
 204             *(dr++) = rsum;
 205
 206             d1 = g[w+1]  - g[-w-1];
 207             d2 = g[1]    - g[-1];
 208             d3 = g[-w+1] - g[w-1];
 209             d4 = g[-w]   - g[w];
 210
 211             rsum = d1 + d2 + d3;
 212             if (rsum < 0) rsum = -rsum;
 213             d1 = d1 - d2 - d4;         /* vertical gradient */
 214             if (d1 < 0) d1 = -d1;
 215             if (d1 > rsum) rsum = d1;
 216             rsum /= 3;
 217
 218             *(dg++) = rsum;
 219
 220             d1 = b[w+1]  - b[-w-1];
 221             d2 = b[1]    - b[-1];
 222             d3 = b[-w+1] - b[w-1];
 223             d4 = b[-w]   - b[w];
 224
 225             rsum = d1 + d2 + d3;
 226             if (rsum < 0) rsum = -rsum;
 227             d1 = d1 - d2 - d4;         /* vertical gradient */
 228             if (d1 < 0) d1 = -d1;
 229             if (d1 > rsum) rsum = d1;
 230             rsum /= 3;
 231
 232             *(db++) = rsum;
 233
 234             r++;
 235             g++;
 236             b++;
 237         }
 238         r++;
 239         g++;
 240         b++;
 241
 242         dr++;
 243         dg++;
 244         db++;
 245     }
 246     {
 247         r = image->data[0];
 248         image2->data[0] = r;
 249         g = image->data[1];
 250         image2->data[1] = g;
 251         b = image->data[2];
 252         image2->data[2] = b;
 253         RReleaseImage(image2);
 254     }
 255
 256 #undef MASK
 257
 258     return True;
 259 }
 260
 261
 262 int
 263 RSmoothImage(RImage *image)
 264 {
 265     register int x, y;
 266     register int v, w;
 267     unsigned char *ptr;
 268     int ch = image->format == RRGBAFormat;
 269
 270     ptr = image->data;
 271
 272
 273     w = image->width*ch;
 274     for (y=0; y<image->height - 1; y++) {
 275         for (x=0; x<image->width - 1; x++) {
 276             v = *ptr + 2 * *(ptr + ch) + 2 * *(ptr + w) + *(ptr + w + ch);
 277             *ptr = v/6;
 278             v = *(ptr+1) + 2 * *(ptr+1 + ch) + 2 * *(ptr+1 + w) + *(ptr+1 + w + ch);
 279             *(ptr+1) = v/6;
 280             v = *(ptr+2) + 2 * *(ptr+2 + ch) + 2 * *(ptr+2 + w) + *(ptr+2 + w + ch);
 281             *(ptr+2) = v/6;
 282
 283             ptr+= ch;
 284         }
 285         /* last column */
 286         v = 3 * *ptr + 3 * *(ptr + w);
 287         *ptr = v/6;
 288         v = 3 * *(ptr+1) + 3 * *(ptr+1 + w);
 289         *(ptr+1) = v/6;
 290         v = 3 * *(ptr+2) + 3 * *(ptr+2 + w);
 291         *(ptr+2) = v/6;
 292
 293         ptr+= ch;
 294     }
 295
 296     /* last line */
 297     for (x=0; x<image->width - 1; x++) {
 298         v = 3 * *ptr + 3 * *(ptr + ch);
 299         *ptr = v/6;
 300         v = 3 * *(ptr+1) + 3 * *(ptr+1 + ch);
 301         *(ptr+1) = v/6;
 302         v = 3 * *(ptr+2) + 3 * *(ptr+2 + ch);
 303         *(ptr+2) = v/6;
 304
 305         ptr+= ch;
 306     }
 307
 308     return True;
 309 }
 310 #endif
 311