src/histogram.c

   1 /*
   2  * Copyright (C) 2008 - 2016 The Geeqie Team
   3  *
   4  * Author: Vladimir Nadvornik
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program 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
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License along
  17  * with this program; if not, write to the Free Software Foundation, Inc.,
  18  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  19  */
  20
  21 #include "main.h"
  22 #include "histogram.h"
  23
  24 #include "pixbuf_util.h"
  25 #include "filedata.h"
  26
  27 #include <math.h>
  28
  29 /*
  30  *----------------------------------------------------------------------------
  31  * image histogram
  32  *----------------------------------------------------------------------------
  33  */
  34
  35 #define HISTMAP_SIZE 256
  36
  37 struct _HistMap {
  38         gulong r[HISTMAP_SIZE];
  39         gulong g[HISTMAP_SIZE];
  40         gulong b[HISTMAP_SIZE];
  41         gulong max[HISTMAP_SIZE];
  42
  43         guint idle_id; /* event source id */
  44         GdkPixbuf *pixbuf;
  45         gint y;
  46 };
  47
  48
  49 Histogram *histogram_new(void)
  50 {
  51         Histogram *histogram;
  52
  53         histogram = g_new0(Histogram, 1);
  54         histogram->histogram_channel = HCHAN_DEFAULT;
  55         histogram->histogram_mode = 0;
  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         histogram->histogram_channel = chan;
  78         return chan;
  79 }
  80
  81 gint histogram_get_channel(Histogram *histogram)
  82 {
  83         if (!histogram) return 0;
  84         return histogram->histogram_channel;
  85 }
  86
  87 gint histogram_set_mode(Histogram *histogram, gint mode)
  88 {
  89         if (!histogram) return 0;
  90         histogram->histogram_mode = mode;
  91         return mode;
  92 }
  93
  94 gint histogram_get_mode(Histogram *histogram)
  95 {
  96         if (!histogram) return 0;
  97         return histogram->histogram_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->histogram_mode)
 119                 switch (histogram->histogram_channel)
 120                         {
 121                         case HCHAN_R:   t1 = _("Log Histogram on Red"); break;
 122                         case HCHAN_G:   t1 = _("Log Histogram on Green"); break;
 123                         case HCHAN_B:   t1 = _("Log Histogram on Blue"); break;
 124                         case HCHAN_RGB: t1 = _("Log Histogram on RGB"); break;
 125                         case HCHAN_MAX: t1 = _("Log Histogram on value"); break;
 126                         }
 127         else
 128                 switch (histogram->histogram_channel)
 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 value"); break;
 135                         }
 136         return t1;
 137 }
 138
 139 static HistMap *histmap_new(void)
 140 {
 141         HistMap *histmap = g_new0(HistMap, 1);
 142         return histmap;
 143 }
 144
 145 void histmap_free(HistMap *histmap)
 146 {
 147         if (!histmap) return;
 148         if (histmap->idle_id) g_source_remove(histmap->idle_id);
 149         if (histmap->pixbuf) g_object_unref(histmap->pixbuf);
 150         g_free(histmap);
 151 }
 152
 153 static gboolean histmap_read(HistMap *histmap, gboolean whole)
 154 {
 155         gint w, h, i, j, srs, has_alpha, step, end_line;
 156         guchar *s_pix;
 157         GdkPixbuf *imgpixbuf = histmap->pixbuf;
 158
 159         w = gdk_pixbuf_get_width(imgpixbuf);
 160         h = gdk_pixbuf_get_height(imgpixbuf);
 161         srs = gdk_pixbuf_get_rowstride(imgpixbuf);
 162         s_pix = gdk_pixbuf_get_pixels(imgpixbuf);
 163         has_alpha = gdk_pixbuf_get_has_alpha(imgpixbuf);
 164
 165         if (whole)
 166                 {
 167                 end_line = h;
 168                 }
 169         else
 170                 {
 171                 gint lines = 1 + 16384 / w;
 172                 end_line = histmap->y + lines;
 173                 if (end_line > h) end_line = h;
 174                 }
 175
 176         step = 3 + !!(has_alpha);
 177         for (i = histmap->y; i < end_line; i++)
 178                 {
 179                 guchar *sp = s_pix + (i * srs); /* 8bit */
 180                 for (j = 0; j < w; j++)
 181                         {
 182                         guint max = sp[0];
 183                         if (sp[1] > max) max = sp[1];
 184                         if (sp[2] > max) max = sp[2];
 185
 186                         histmap->r[sp[0]]++;
 187                         histmap->g[sp[1]]++;
 188                         histmap->b[sp[2]]++;
 189                         histmap->max[max]++;
 190
 191                         sp += step;
 192                         }
 193                 }
 194         histmap->y = end_line;
 195         return end_line >= h;
 196 }
 197
 198 const HistMap *histmap_get(FileData *fd)
 199 {
 200         if (fd->histmap && !fd->histmap->idle_id) return fd->histmap; /* histmap exists and is finished */
 201
 202         return NULL;
 203 }
 204
 205 static gboolean histmap_idle_cb(gpointer data)
 206 {
 207         FileData *fd = data;
 208         if (histmap_read(fd->histmap, FALSE))
 209                 {
 210                 /* finished */
 211                 g_object_unref(fd->histmap->pixbuf); /*pixbuf is no longer needed */
 212                 fd->histmap->pixbuf = NULL;
 213                 fd->histmap->idle_id = 0;
 214                 file_data_send_notification(fd, NOTIFY_HISTMAP);
 215                 return FALSE;
 216                 }
 217         return TRUE;
 218 }
 219
 220 gboolean histmap_start_idle(FileData *fd)
 221 {
 222         if (fd->histmap || !fd->pixbuf) return FALSE;
 223
 224         fd->histmap = histmap_new();
 225         fd->histmap->pixbuf = fd->pixbuf;
 226         g_object_ref(fd->histmap->pixbuf);
 227
 228         fd->histmap->idle_id = g_idle_add_full(G_PRIORITY_DEFAULT_IDLE, histmap_idle_cb, fd, NULL);
 229         return TRUE;
 230 }
 231
 232
 233 static void histogram_vgrid(Histogram *histogram, GdkPixbuf *pixbuf, gint x, gint y, gint width, gint height)
 234 {
 235         guint i;
 236         float add;
 237
 238         if (histogram->vgrid == 0) return;
 239
 240         add = width / (float)histogram->vgrid;
 241
 242         for (i = 1; i < histogram->vgrid; i++)
 243                 {
 244                 gint xpos = x + (int)(i * add + 0.5);
 245
 246                 pixbuf_draw_line(pixbuf, x, y, width, height, xpos, y, xpos, y + height,
 247                                  histogram->grid_color.R,
 248                                  histogram->grid_color.G,
 249                                  histogram->grid_color.B,
 250                                  histogram->grid_color.A);
 251                 }
 252 }
 253
 254 static void histogram_hgrid(Histogram *histogram, GdkPixbuf *pixbuf, gint x, gint y, gint width, gint height)
 255 {
 256         guint i;
 257         float add;
 258
 259         if (histogram->hgrid == 0) return;
 260
 261         add = height / (float)histogram->hgrid;
 262
 263         for (i = 1; i < histogram->hgrid; i++)
 264                 {
 265                 gint ypos = y + (int)(i * add + 0.5);
 266
 267                 pixbuf_draw_line(pixbuf, x, y, width, height, x, ypos, x + width, ypos,
 268                                  histogram->grid_color.R,
 269                                  histogram->grid_color.G,
 270                                  histogram->grid_color.B,
 271                                  histogram->grid_color.A);
 272                 }
 273 }
 274
 275 gboolean histogram_draw(Histogram *histogram, const HistMap *histmap, GdkPixbuf *pixbuf, gint x, gint y, gint width, gint height)
 276 {
 277         /** @FIXME use the coordinates correctly */
 278         gint i;
 279         gulong max = 0;
 280         gdouble logmax;
 281         gint combine = (HISTMAP_SIZE - 1) / width + 1;
 282         gint ypos = y + height;
 283
 284         if (!histogram || !histmap) return FALSE;
 285
 286         /* Draw the grid */
 287         histogram_vgrid(histogram, pixbuf, x, y, width, height);
 288         histogram_hgrid(histogram, pixbuf, x, y, width, height);
 289
 290         /* exclude overexposed and underexposed */
 291         for (i = 1; i < HISTMAP_SIZE - 1; i++)
 292                 {
 293                 if (histmap->r[i] > max) max = histmap->r[i];
 294                 if (histmap->g[i] > max) max = histmap->g[i];
 295                 if (histmap->b[i] > max) max = histmap->b[i];
 296                 if (histmap->max[i] > max) max = histmap->max[i];
 297                 }
 298
 299         if (max > 0)
 300                 logmax = log(max);
 301         else
 302                 logmax = 1.0;
 303
 304         for (i = 0; i < width; i++)
 305                 {
 306                 gint j;
 307                 glong v[4] = {0, 0, 0, 0};
 308                 gint rplus = 0;
 309                 gint gplus = 0;
 310                 gint bplus = 0;
 311                 gint ii = i * HISTMAP_SIZE / width;
 312                 gint xpos = x + i;
 313                 gint num_chan;
 314
 315                 for (j = 0; j < combine; j++)
 316                         {
 317                         guint p = ii + j;
 318                         v[0] += histmap->r[p];
 319                         v[1] += histmap->g[p];
 320                         v[2] += histmap->b[p];
 321                         v[3] += histmap->max[p];
 322                         }
 323
 324                 for (j = 0; combine > 1 && j < 4; j++)
 325                         v[j] /= combine;
 326
 327                 num_chan = (histogram->histogram_channel == HCHAN_RGB) ? 3 : 1;
 328                 for (j = 0; j < num_chan; j++)
 329                         {
 330                         gint chanmax;
 331                         if (histogram->histogram_channel == HCHAN_RGB)
 332                                 {
 333                                 chanmax = HCHAN_R;
 334                                 if (v[HCHAN_G] > v[HCHAN_R]) chanmax = HCHAN_G;
 335                                 if (v[HCHAN_B] > v[chanmax]) chanmax = HCHAN_B;
 336                                 }
 337                         else
 338                                 {
 339                                 chanmax = histogram->histogram_channel;
 340                                 }
 341
 342                                 {
 343                                 gulong pt;
 344                                 gint r = rplus;
 345                                 gint g = gplus;
 346                                 gint b = bplus;
 347
 348                                 switch (chanmax)
 349                                         {
 350                                         case HCHAN_R: rplus = r = 255; break;
 351                                         case HCHAN_G: gplus = g = 255; break;
 352                                         case HCHAN_B: bplus = b = 255; break;
 353                                         }
 354
 355                                 switch (histogram->histogram_channel)
 356                                         {
 357                                         case HCHAN_RGB:
 358                                                 if (r == 255 && g == 255 && b == 255)
 359                                                         {
 360                                                         r = 0;  b = 0;  g = 0;
 361                                                         }
 362                                                 break;
 363                                         case HCHAN_R:           b = 0;  g = 0;  break;
 364                                         case HCHAN_G:   r = 0;  b = 0;          break;
 365                                         case HCHAN_B:   r = 0;          g = 0;  break;
 366                                         case HCHAN_MAX: r = 0;  b = 0;  g = 0;  break;
 367                                         }
 368
 369                                 if (v[chanmax] == 0)
 370                                         pt = 0;
 371                                 else if (histogram->histogram_mode)
 372                                         pt = ((gdouble)log(v[chanmax])) / logmax * (height - 1);
 373                                 else
 374                                         pt = ((gdouble)v[chanmax]) / max * (height - 1);
 375
 376                                 pixbuf_draw_line(pixbuf,
 377                                         x, y, width, height,
 378                                         xpos, ypos, xpos, ypos - pt,
 379                                         r, g, b, 255);
 380                                 }
 381
 382                         v[chanmax] = -1;
 383                         }
 384                 }
 385
 386         return TRUE;
 387 }
 388
 389 void histogram_notify_cb(FileData *fd, NotifyType type, gpointer data)
 390 {
 391         if ((type & NOTIFY_REREAD) && fd->histmap)
 392                 {
 393                 DEBUG_1("Notify histogram: %s %04x", fd->path, type);
 394                 histmap_free(fd->histmap);
 395                 fd->histmap = NULL;
 396                 }
 397 }
 398
 399 /* vim: set shiftwidth=8 softtabstop=0 cindent cinoptions={1s: */