src/histogram.c

   1 /*
   2  * Geeqie
   3  * Copyright (C) 2008 - 2009 The Geeqie Team
   4  *
   5  * Author: Vladimir Nadvornik
   6  * based on a patch by Uwe Ohse
   7  *
   8  * This software is released under the GNU General Public License (GNU GPL).
   9  * Please read the included file COPYING for more information.
  10  * This software comes with no warranty of any kind, use at your own risk!
  11  */
  12
  13 #include "main.h"
  14 #include "histogram.h"
  15
  16 #include "pixbuf_util.h"
  17
  18 #include <math.h>
  19
  20 /*
  21  *----------------------------------------------------------------------------
  22  * image histogram
  23  *----------------------------------------------------------------------------
  24  */
  25
  26 #define HISTMAP_SIZE 256
  27 typedef enum {
  28         HISTMAP_CHANNEL_R = 0,
  29         HISTMAP_CHANNEL_G,
  30         HISTMAP_CHANNEL_B,
  31         HISTMAP_CHANNEL_AVG,
  32         HISTMAP_CHANNEL_MAX,
  33         HISTMAP_CHANNELS
  34 } HistMapChannels;
  35
  36 struct _HistMap {
  37         gulong histmap[HISTMAP_SIZE * HISTMAP_CHANNELS];
  38         gulong area;
  39 };
  40
  41 struct _Histogram {
  42         gint channel_mode;
  43         gint log_mode;
  44         guint vgrid; /* number of vertical divisions, 0 for none */
  45         guint hgrid; /* number of horizontal divisions, 0 for none */
  46
  47 };
  48
  49 Histogram *histogram_new(void)
  50 {
  51         Histogram *histogram;
  52
  53         histogram = g_new0(Histogram, 1);
  54         histogram->channel_mode = options->histogram.last_channel_mode;
  55         histogram->log_mode = options->histogram.last_log_mode;
  56         histogram->vgrid = 5;
  57         histogram->hgrid = 3;
  58
  59         return histogram;
  60 }
  61
  62 void histogram_free(Histogram *histogram)
  63 {
  64         g_free(histogram);
  65 }
  66
  67
  68 gint histogram_set_channel(Histogram *histogram, gint chan)
  69 {
  70         if (!histogram) return 0;
  71         options->histogram.last_channel_mode = histogram->channel_mode = chan;
  72         return chan;
  73 }
  74
  75 gint histogram_get_channel(Histogram *histogram)
  76 {
  77         if (!histogram) return 0;
  78         return histogram->channel_mode;
  79 }
  80
  81 gint histogram_set_mode(Histogram *histogram, gint mode)
  82 {
  83         if (!histogram) return 0;
  84         options->histogram.last_log_mode = histogram->log_mode = mode;
  85         return mode;
  86 }
  87
  88 gint histogram_get_mode(Histogram *histogram)
  89 {
  90         if (!histogram) return 0;
  91         return histogram->log_mode;
  92 }
  93
  94 const gchar *histogram_label(Histogram *histogram)
  95 {
  96         const gchar *t1 = "";
  97
  98         if (!histogram) return NULL;
  99
 100         if (histogram->log_mode)
 101                 switch (histogram->channel_mode)
 102                         {
 103                         case HCHAN_R:   t1 = _("logarithmical histogram on red"); break;
 104                         case HCHAN_G:   t1 = _("logarithmical histogram on green"); break;
 105                         case HCHAN_B:   t1 = _("logarithmical histogram on blue"); break;
 106                         case HCHAN_VAL: t1 = _("logarithmical histogram on value"); break;
 107                         case HCHAN_RGB: t1 = _("logarithmical histogram on RGB"); break;
 108                         case HCHAN_MAX: t1 = _("logarithmical histogram on max value"); break;
 109                         }
 110         else
 111                 switch (histogram->channel_mode)
 112                         {
 113                         case HCHAN_R:   t1 = _("linear histogram on red"); break;
 114                         case HCHAN_G:   t1 = _("linear histogram on green"); break;
 115                         case HCHAN_B:   t1 = _("linear histogram on blue"); break;
 116                         case HCHAN_VAL: t1 = _("linear histogram on value"); break;
 117                         case HCHAN_RGB: t1 = _("linear histogram on RGB"); break;
 118                         case HCHAN_MAX: t1 = _("linear histogram on max value"); break;
 119                         }
 120         return t1;
 121 }
 122
 123 static HistMap *histmap_read(GdkPixbuf *imgpixbuf)
 124 {
 125         gint w, h, i, j, srs, has_alpha, step;
 126         guchar *s_pix;
 127
 128         HistMap *histmap;
 129
 130         w = gdk_pixbuf_get_width(imgpixbuf);
 131         h = gdk_pixbuf_get_height(imgpixbuf);
 132         srs = gdk_pixbuf_get_rowstride(imgpixbuf);
 133         s_pix = gdk_pixbuf_get_pixels(imgpixbuf);
 134         has_alpha = gdk_pixbuf_get_has_alpha(imgpixbuf);
 135
 136         histmap = g_new0(HistMap, 1);
 137
 138         step = 3 + !!(has_alpha);
 139         for (i = 0; i < h; i++)
 140                 {
 141                 guchar *sp = s_pix + (i * srs); /* 8bit */
 142                 for (j = 0; j < w; j++)
 143                         {
 144                         guint avg = (sp[0] + sp[1] + sp[2]) / 3;
 145                         guint max = sp[0];
 146                         if (sp[1] > max) max = sp[1];
 147                         if (sp[2] > max) max = sp[2];
 148
 149                         histmap->histmap[sp[0] * HISTMAP_CHANNELS + HISTMAP_CHANNEL_R]++;
 150                         histmap->histmap[sp[1] * HISTMAP_CHANNELS + HISTMAP_CHANNEL_G]++;
 151                         histmap->histmap[sp[2] * HISTMAP_CHANNELS + HISTMAP_CHANNEL_B]++;
 152                         histmap->histmap[avg   * HISTMAP_CHANNELS + HISTMAP_CHANNEL_AVG]++;
 153                         histmap->histmap[max   * HISTMAP_CHANNELS + HISTMAP_CHANNEL_MAX]++;
 154                         sp += step;
 155                         }
 156                 }
 157         histmap->area = w * h;
 158         return histmap;
 159 }
 160
 161 const HistMap *histmap_get(FileData *fd)
 162 {
 163         if (fd->histmap) return fd->histmap;
 164
 165         if (fd->pixbuf)
 166                 {
 167                 fd->histmap = histmap_read(fd->pixbuf);
 168                 return fd->histmap;
 169                 }
 170         return NULL;
 171 }
 172
 173 static void histogram_vgrid(Histogram *histogram, GdkPixbuf *pixbuf, gint x, gint y, gint width, gint height)
 174 {
 175         static gint c = 160;
 176         static gint alpha = 250;
 177         guint i;
 178         float add;
 179
 180         if (histogram->vgrid == 0) return;
 181
 182         add = width / (float)histogram->vgrid;
 183
 184         for (i = 1; i < histogram->vgrid; i++)
 185                 {
 186                 gint xpos = x + (int)(i * add + 0.5);
 187
 188                 pixbuf_draw_line(pixbuf, x, y, width, height, xpos, y, xpos, y + height, c, c, c, alpha);
 189                 }
 190 }
 191
 192 static void histogram_hgrid(Histogram *histogram, GdkPixbuf *pixbuf, gint x, gint y, gint width, gint height)
 193 {
 194         static gint c = 160;
 195         static gint alpha = 250;
 196         guint i;
 197         float add;
 198
 199         if (histogram->hgrid == 0) return;
 200
 201         add = height / (float)histogram->hgrid;
 202
 203         for (i = 1; i < histogram->hgrid; i++)
 204                 {
 205                 gint ypos = y + (int)(i * add + 0.5);
 206
 207                 pixbuf_draw_line(pixbuf, x, y, width, height, x, ypos, x + width, ypos, c, c, c, alpha);
 208                 }
 209 }
 210
 211 gint histogram_draw(Histogram *histogram, const HistMap *histmap, GdkPixbuf *pixbuf, gint x, gint y, gint width, gint height)
 212 {
 213         /* FIXME: use the coordinates correctly */
 214         gint i;
 215         gulong max = 0;
 216         gdouble logmax;
 217
 218         if (!histogram || !histmap) return 0;
 219
 220         /* Draw the grid */
 221         histogram_vgrid(histogram, pixbuf, x, y, width, height);
 222         histogram_hgrid(histogram, pixbuf, x, y, width, height);
 223
 224         for (i = 0; i < 1024; i++) {
 225 #if 0
 226                 /* this is probably broken for MAX or VAL mode */
 227                 gint flag = 0;
 228
 229                 switch (histogram->channel_mode)
 230                         {
 231                         case HCHAN_RGB: if ((i % HISTMAP_CHANNELS) < 3) flag = 1; break;
 232                         case HCHAN_R:   if ((i % HISTMAP_CHANNELS) == HISTMAP_CHANNEL_R) flag = 1; break;
 233                         case HCHAN_G:   if ((i % HISTMAP_CHANNELS) == HISTMAP_CHANNEL_G) flag = 1; break;
 234                         case HCHAN_B:   if ((i % HISTMAP_CHANNELS) == HISTMAP_CHANNEL_B) flag = 1; break;
 235                         case HCHAN_VAL: if ((i % HISTMAP_CHANNELS) == HISTMAP_CHANNEL_AVG) flag = 1; break;
 236                         case HCHAN_MAX: if ((i % HISTMAP_CHANNELS) == HISTMAP_CHANNEL_MAX) flag = 1; break;
 237                         }
 238                 if (flag && histmap->histmap[i] > max) max = histmap->histmap[i];
 239 #else
 240                 if (histmap->histmap[i] > max) max = histmap->histmap[i];
 241 #endif
 242         }
 243
 244         logmax = log(max);
 245         for (i = 0; i < width; i++)
 246                 {
 247                 gint j;
 248                 glong v[4] = {0, 0, 0, 0};
 249                 gint rplus = 0;
 250                 gint gplus = 0;
 251                 gint bplus = 0;
 252                 gint ii = i * HISTMAP_SIZE / width;
 253                 gint combine  = (HISTMAP_SIZE - 1) / width + 1;
 254
 255                 for (j = 0; j < combine; j++)
 256                         {
 257                         v[0] += histmap->histmap[(ii + j) * HISTMAP_CHANNELS + HISTMAP_CHANNEL_R]; // r
 258                         v[1] += histmap->histmap[(ii + j) * HISTMAP_CHANNELS + HISTMAP_CHANNEL_G]; // g
 259                         v[2] += histmap->histmap[(ii + j) * HISTMAP_CHANNELS + HISTMAP_CHANNEL_B]; // b
 260                         v[3] += histmap->histmap[(ii + j) * HISTMAP_CHANNELS +
 261                                 ((histogram->channel_mode == HCHAN_VAL) ? HISTMAP_CHANNEL_AVG : HISTMAP_CHANNEL_MAX)]; // value, max
 262                         }
 263
 264                 for (j = 0; j < 4; j++)
 265                         {
 266                         v[j] /= combine;
 267                         }
 268
 269                 for (j = 0; j < 4; j++)
 270                         {
 271                         gint max2 = 0;
 272                         gint k;
 273
 274                         for (k = 1; k < 4; k++)
 275                                 if (v[k] > v[max2]) max2 = k;
 276
 277                         if (histogram->channel_mode >= HCHAN_RGB
 278                             || max2 == histogram->channel_mode)
 279                                 {
 280                                 gulong pt;
 281                                 gint r = rplus;
 282                                 gint g = gplus;
 283                                 gint b = bplus;
 284
 285                                 switch (max2)
 286                                         {
 287                                         case HCHAN_R: rplus = r = 255; break;
 288                                         case HCHAN_G: gplus = g = 255; break;
 289                                         case HCHAN_B: bplus = b = 255; break;
 290                                         }
 291
 292                                 switch (histogram->channel_mode)
 293                                         {
 294                                         case HCHAN_RGB:
 295                                                 if (r == 255 && g == 255 && b == 255)
 296                                                         {
 297                                                         r = 0; b = 0; g = 0;
 298                                                         }
 299                                                 break;
 300                                         case HCHAN_R:          b = 0; g = 0; break;
 301                                         case HCHAN_G:   r = 0; b = 0;        break;
 302                                         case HCHAN_B:   r = 0;        g = 0; break;
 303                                         case HCHAN_MAX:
 304                                         case HCHAN_VAL: r = 0; b = 0; g = 0; break;
 305                                         }
 306
 307                                 if (v[max2] == 0)
 308                                         pt = 0;
 309                                 else if (histogram->log_mode)
 310                                         pt = ((float)log(v[max2])) / logmax * (height - 1);
 311                                 else
 312                                         pt = ((float)v[max2])/ max * (height - 1);
 313
 314                                 pixbuf_draw_line(pixbuf,
 315                                         x, y, width, height,
 316                                         x + i, y + height, x + i, y + height - pt,
 317                                         r, g, b, 255);
 318                                 }
 319                         v[max2] = -1;
 320                         }
 321                 }
 322
 323         return TRUE;
 324 }
 325
 326 void histogram_notify_cb(FileData *fd, NotifyType type, gpointer data)
 327 {
 328         if (type != NOTIFY_TYPE_INTERNAL && fd->histmap)
 329                 {
 330                 g_free(fd->histmap);
 331                 fd->histmap = NULL;
 332                 }
 333 }
 334
 335 /* vim: set shiftwidth=8 softtabstop=0 cindent cinoptions={1s: */