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
  28 struct _HistMap {
  29         gulong r[HISTMAP_SIZE];
  30         gulong g[HISTMAP_SIZE];
  31         gulong b[HISTMAP_SIZE];
  32         gulong max[HISTMAP_SIZE];
  33 };
  34
  35 struct _Histogram {
  36         gint channel_mode; /* drawing mode for histogram */
  37         gint log_mode;     /* logarithmical or not */
  38         guint vgrid; /* number of vertical divisions, 0 for none */
  39         guint hgrid; /* number of horizontal divisions, 0 for none */
  40         struct {
  41                 int R; /* red */
  42                 int G; /* green */
  43                 int B; /* blue */
  44                 int A; /* alpha */
  45         } grid_color;  /* grid color */
  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
  57         /* grid */
  58         histogram->vgrid = 5;
  59         histogram->hgrid = 3;
  60         histogram->grid_color.R = 160;
  61         histogram->grid_color.G = 160;
  62         histogram->grid_color.B = 160;
  63         histogram->grid_color.A = 250;
  64
  65         return histogram;
  66 }
  67
  68 void histogram_free(Histogram *histogram)
  69 {
  70         g_free(histogram);
  71 }
  72
  73
  74 gint histogram_set_channel(Histogram *histogram, gint chan)
  75 {
  76         if (!histogram) return 0;
  77         options->histogram.last_channel_mode = histogram->channel_mode = chan;
  78         return chan;
  79 }
  80
  81 gint histogram_get_channel(Histogram *histogram)
  82 {
  83         if (!histogram) return 0;
  84         return histogram->channel_mode;
  85 }
  86
  87 gint histogram_set_mode(Histogram *histogram, gint mode)
  88 {
  89         if (!histogram) return 0;
  90         options->histogram.last_log_mode = histogram->log_mode = mode;
  91         return mode;
  92 }
  93
  94 gint histogram_get_mode(Histogram *histogram)
  95 {
  96         if (!histogram) return 0;
  97         return histogram->log_mode;
  98 }
  99
 100 gint histogram_toggle_channel(Histogram *histogram)
 101 {
 102         if (!histogram) return 0;
 103         return histogram_set_channel(histogram, (histogram_get_channel(histogram)+1)%HCHAN_COUNT);
 104 }
 105
 106 gint histogram_toggle_mode(Histogram *histogram)
 107 {
 108         if (!histogram) return 0;
 109         return histogram_set_mode(histogram, !histogram_get_mode(histogram));
 110 }
 111
 112 const gchar *histogram_label(Histogram *histogram)
 113 {
 114         const gchar *t1 = "";
 115
 116         if (!histogram) return NULL;
 117
 118         if (histogram->log_mode)
 119                 switch (histogram->channel_mode)
 120                         {
 121                         case HCHAN_R:   t1 = _("logarithmical histogram on red"); break;
 122                         case HCHAN_G:   t1 = _("logarithmical histogram on green"); break;
 123                         case HCHAN_B:   t1 = _("logarithmical histogram on blue"); break;
 124                         case HCHAN_RGB: t1 = _("logarithmical histogram on RGB"); break;
 125                         case HCHAN_MAX: t1 = _("logarithmical histogram on max value"); break;
 126                         }
 127         else
 128                 switch (histogram->channel_mode)
 129                         {
 130                         case HCHAN_R:   t1 = _("linear histogram on red"); break;
 131                         case HCHAN_G:   t1 = _("linear histogram on green"); break;
 132                         case HCHAN_B:   t1 = _("linear histogram on blue"); break;
 133                         case HCHAN_RGB: t1 = _("linear histogram on RGB"); break;
 134                         case HCHAN_MAX: t1 = _("linear histogram on max value"); break;
 135                         }
 136         return t1;
 137 }
 138
 139 static HistMap *histmap_read(GdkPixbuf *imgpixbuf)
 140 {
 141         gint w, h, i, j, srs, has_alpha, step;
 142         guchar *s_pix;
 143         HistMap *histmap;
 144
 145         w = gdk_pixbuf_get_width(imgpixbuf);
 146         h = gdk_pixbuf_get_height(imgpixbuf);
 147         srs = gdk_pixbuf_get_rowstride(imgpixbuf);
 148         s_pix = gdk_pixbuf_get_pixels(imgpixbuf);
 149         has_alpha = gdk_pixbuf_get_has_alpha(imgpixbuf);
 150
 151         histmap = g_new0(HistMap, 1);
 152
 153         step = 3 + !!(has_alpha);
 154         for (i = 0; i < h; i++)
 155                 {
 156                 guchar *sp = s_pix + (i * srs); /* 8bit */
 157                 for (j = 0; j < w; j++)
 158                         {
 159                         guint max = sp[0];
 160                         if (sp[1] > max) max = sp[1];
 161                         if (sp[2] > max) max = sp[2];
 162
 163                         histmap->r[sp[0]]++;
 164                         histmap->g[sp[1]]++;
 165                         histmap->b[sp[2]]++;
 166                         histmap->max[max]++;
 167
 168                         sp += step;
 169                         }
 170                 }
 171
 172         return histmap;
 173 }
 174
 175 const HistMap *histmap_get(FileData *fd)
 176 {
 177         if (fd->histmap) return fd->histmap;
 178
 179         if (fd->pixbuf)
 180                 {
 181                 fd->histmap = histmap_read(fd->pixbuf);
 182                 return fd->histmap;
 183                 }
 184         return NULL;
 185 }
 186
 187 static void histogram_vgrid(Histogram *histogram, GdkPixbuf *pixbuf, gint x, gint y, gint width, gint height)
 188 {
 189         guint i;
 190         float add;
 191
 192         if (histogram->vgrid == 0) return;
 193
 194         add = width / (float)histogram->vgrid;
 195
 196         for (i = 1; i < histogram->vgrid; i++)
 197                 {
 198                 gint xpos = x + (int)(i * add + 0.5);
 199
 200                 pixbuf_draw_line(pixbuf, x, y, width, height, xpos, y, xpos, y + height,
 201                                  histogram->grid_color.R,
 202                                  histogram->grid_color.G,
 203                                  histogram->grid_color.B,
 204                                  histogram->grid_color.A);
 205                 }
 206 }
 207
 208 static void histogram_hgrid(Histogram *histogram, GdkPixbuf *pixbuf, gint x, gint y, gint width, gint height)
 209 {
 210         guint i;
 211         float add;
 212
 213         if (histogram->hgrid == 0) return;
 214
 215         add = height / (float)histogram->hgrid;
 216
 217         for (i = 1; i < histogram->hgrid; i++)
 218                 {
 219                 gint ypos = y + (int)(i * add + 0.5);
 220
 221                 pixbuf_draw_line(pixbuf, x, y, width, height, x, ypos, x + width, ypos,
 222                                  histogram->grid_color.R,
 223                                  histogram->grid_color.G,
 224                                  histogram->grid_color.B,
 225                                  histogram->grid_color.A);
 226                 }
 227 }
 228
 229 gint histogram_draw(Histogram *histogram, const HistMap *histmap, GdkPixbuf *pixbuf, gint x, gint y, gint width, gint height)
 230 {
 231         /* FIXME: use the coordinates correctly */
 232         gint i;
 233         gulong max = 0;
 234         gdouble logmax;
 235         gint combine = (HISTMAP_SIZE - 1) / width + 1;
 236         gint ypos = y + height;
 237
 238         if (!histogram || !histmap) return 0;
 239
 240         /* Draw the grid */
 241         histogram_vgrid(histogram, pixbuf, x, y, width, height);
 242         histogram_hgrid(histogram, pixbuf, x, y, width, height);
 243
 244         for (i = 0; i < HISTMAP_SIZE; i++)
 245                 {
 246                 if (histmap->r[i] > max) max = histmap->r[i];
 247                 if (histmap->g[i] > max) max = histmap->g[i];
 248                 if (histmap->b[i] > max) max = histmap->b[i];
 249                 }
 250
 251         if (max > 0)
 252                 logmax = log(max);
 253         else
 254                 logmax = 1.0;
 255
 256         for (i = 0; i < width; i++)
 257                 {
 258                 gint j;
 259                 glong v[4] = {0, 0, 0, 0};
 260                 gint rplus = 0;
 261                 gint gplus = 0;
 262                 gint bplus = 0;
 263                 gint ii = i * HISTMAP_SIZE / width;
 264                 gint xpos = x + i;
 265
 266                 for (j = 0; j < combine; j++)
 267                         {
 268                         guint p = ii + j;
 269                         v[0] += histmap->r[p];
 270                         v[1] += histmap->g[p];
 271                         v[2] += histmap->b[p];
 272                         v[3] += histmap->max[p];
 273                         }
 274
 275                 for (j = 0; combine > 1 && j < 4; j++)
 276                         v[j] /= combine;
 277
 278                 for (j = 0; j < 4; j++)
 279                         {
 280                         gint k;
 281                         gint chanmax = 0;
 282
 283                         for (k = 1; k < 3; k++)
 284                                 if (v[k] > v[chanmax])
 285                                         chanmax = k;
 286
 287                         if (histogram->channel_mode >= HCHAN_RGB
 288                             || chanmax == histogram->channel_mode)
 289                                 {
 290                                 gulong pt;
 291                                 gint r = rplus;
 292                                 gint g = gplus;
 293                                 gint b = bplus;
 294
 295                                 switch (chanmax)
 296                                         {
 297                                         case 0: rplus = r = 255; break;
 298                                         case 1: gplus = g = 255; break;
 299                                         case 2: bplus = b = 255; break;
 300                                         }
 301
 302                                 switch (histogram->channel_mode)
 303                                         {
 304                                         case HCHAN_RGB:
 305                                                 if (r == 255 && g == 255 && b == 255)
 306                                                         {
 307                                                         r = 0; b = 0; g = 0;
 308                                                         }
 309                                                 break;
 310                                         case HCHAN_R:     b = 0; g = 0; break;
 311                                         case HCHAN_G:   r = 0; b = 0;   break;
 312                                         case HCHAN_B:   r = 0;  g = 0; break;
 313                                         case HCHAN_MAX: r = 0; b = 0; g = 0; break;
 314                                         }
 315
 316                                 if (v[chanmax] == 0)
 317                                         pt = 0;
 318                                 else if (histogram->log_mode)
 319                                         pt = ((gdouble)log(v[chanmax])) / logmax * (height - 1);
 320                                 else
 321                                         pt = ((gdouble)v[chanmax]) / max * (height - 1);
 322
 323                                 pixbuf_draw_line(pixbuf,
 324                                         x, y, width, height,
 325                                         xpos, ypos, xpos, ypos - pt,
 326                                         r, g, b, 255);
 327                                 }
 328
 329                         v[chanmax] = -1;
 330                         }
 331                 }
 332
 333         return TRUE;
 334 }
 335
 336 void histogram_notify_cb(FileData *fd, NotifyType type, gpointer data)
 337 {
 338         if (type != NOTIFY_TYPE_INTERNAL && fd->histmap)
 339                 {
 340                 g_free(fd->histmap);
 341                 fd->histmap = NULL;
 342                 }
 343 }
 344
 345 /* vim: set shiftwidth=8 softtabstop=0 cindent cinoptions={1s: */