src/histogram.cc

   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 <cmath>
  28
  29 /*
  30  *----------------------------------------------------------------------------
  31  * image histogram
  32  *----------------------------------------------------------------------------
  33  */
  34
  35 enum {
  36         HISTMAP_SIZE = 256
  37 };
  38
  39 struct HistMap {
  40         gulong r[HISTMAP_SIZE];
  41         gulong g[HISTMAP_SIZE];
  42         gulong b[HISTMAP_SIZE];
  43         gulong max[HISTMAP_SIZE];
  44
  45         guint idle_id; /* event source id */
  46         GdkPixbuf *pixbuf;
  47         gint y;
  48 };
  49
  50
  51 Histogram *histogram_new()
  52 {
  53         Histogram *histogram;
  54
  55         histogram = g_new0(Histogram, 1);
  56         histogram->histogram_channel = HCHAN_DEFAULT;
  57         histogram->histogram_mode = 0;
  58
  59         /* grid */
  60         histogram->vgrid = 5;
  61         histogram->hgrid = 3;
  62         histogram->grid_color.R = 160;
  63         histogram->grid_color.G = 160;
  64         histogram->grid_color.B = 160;
  65         histogram->grid_color.A = 250;
  66
  67         return histogram;
  68 }
  69
  70 void histogram_free(Histogram *histogram)
  71 {
  72         g_free(histogram);
  73 }
  74
  75
  76 gint histogram_set_channel(Histogram *histogram, gint chan)
  77 {
  78         if (!histogram) return 0;
  79         histogram->histogram_channel = chan;
  80         return chan;
  81 }
  82
  83 gint histogram_get_channel(Histogram *histogram)
  84 {
  85         if (!histogram) return 0;
  86         return histogram->histogram_channel;
  87 }
  88
  89 gint histogram_set_mode(Histogram *histogram, gint mode)
  90 {
  91         if (!histogram) return 0;
  92         histogram->histogram_mode = mode;
  93         return mode;
  94 }
  95
  96 gint histogram_get_mode(Histogram *histogram)
  97 {
  98         if (!histogram) return 0;
  99         return histogram->histogram_mode;
 100 }
 101
 102 gint histogram_toggle_channel(Histogram *histogram)
 103 {
 104         if (!histogram) return 0;
 105         return histogram_set_channel(histogram, (histogram_get_channel(histogram)+1)%HCHAN_COUNT);
 106 }
 107
 108 gint histogram_toggle_mode(Histogram *histogram)
 109 {
 110         if (!histogram) return 0;
 111         return histogram_set_mode(histogram, !histogram_get_mode(histogram));
 112 }
 113
 114 const gchar *histogram_label(Histogram *histogram)
 115 {
 116         const gchar *t1 = "";
 117
 118         if (!histogram) return nullptr;
 119
 120         if (histogram->histogram_mode)
 121                 switch (histogram->histogram_channel)
 122                         {
 123                         case HCHAN_R:   t1 = _("Log Histogram on Red"); break;
 124                         case HCHAN_G:   t1 = _("Log Histogram on Green"); break;
 125                         case HCHAN_B:   t1 = _("Log Histogram on Blue"); break;
 126                         case HCHAN_RGB: t1 = _("Log Histogram on RGB"); break;
 127                         case HCHAN_MAX: t1 = _("Log Histogram on value"); break;
 128                         }
 129         else
 130                 switch (histogram->histogram_channel)
 131                         {
 132                         case HCHAN_R:   t1 = _("Linear Histogram on Red"); break;
 133                         case HCHAN_G:   t1 = _("Linear Histogram on Green"); break;
 134                         case HCHAN_B:   t1 = _("Linear Histogram on Blue"); break;
 135                         case HCHAN_RGB: t1 = _("Linear Histogram on RGB"); break;
 136                         case HCHAN_MAX: t1 = _("Linear Histogram on value"); break;
 137                         }
 138         return t1;
 139 }
 140
 141 static HistMap *histmap_new()
 142 {
 143         auto histmap = g_new0(HistMap, 1);
 144         return histmap;
 145 }
 146
 147 void histmap_free(HistMap *histmap)
 148 {
 149         if (!histmap) return;
 150         if (histmap->idle_id) g_source_remove(histmap->idle_id);
 151         if (histmap->pixbuf) g_object_unref(histmap->pixbuf);
 152         g_free(histmap);
 153 }
 154
 155 static gboolean histmap_read(HistMap *histmap, gboolean whole)
 156 {
 157         gint w;
 158         gint h;
 159         gint i;
 160         gint j;
 161         gint srs;
 162         gint has_alpha;
 163         gint step;
 164         gint end_line;
 165         guchar *s_pix;
 166         GdkPixbuf *imgpixbuf = histmap->pixbuf;
 167
 168         w = gdk_pixbuf_get_width(imgpixbuf);
 169         h = gdk_pixbuf_get_height(imgpixbuf);
 170         srs = gdk_pixbuf_get_rowstride(imgpixbuf);
 171         s_pix = gdk_pixbuf_get_pixels(imgpixbuf);
 172         has_alpha = gdk_pixbuf_get_has_alpha(imgpixbuf);
 173
 174         if (whole)
 175                 {
 176                 end_line = h;
 177                 }
 178         else
 179                 {
 180                 gint lines = 1 + 16384 / w;
 181                 end_line = histmap->y + lines;
 182                 if (end_line > h) end_line = h;
 183                 }
 184
 185         step = 3 + !!(has_alpha);
 186         for (i = histmap->y; i < end_line; i++)
 187                 {
 188                 guchar *sp = s_pix + (i * srs); /* 8bit */
 189                 for (j = 0; j < w; j++)
 190                         {
 191                         guint max = sp[0];
 192                         if (sp[1] > max) max = sp[1];
 193                         if (sp[2] > max) max = sp[2];
 194
 195                         histmap->r[sp[0]]++;
 196                         histmap->g[sp[1]]++;
 197                         histmap->b[sp[2]]++;
 198                         histmap->max[max]++;
 199
 200                         sp += step;
 201                         }
 202                 }
 203         histmap->y = end_line;
 204         return end_line >= h;
 205 }
 206
 207 const HistMap *histmap_get(FileData *fd)
 208 {
 209         if (fd->histmap && !fd->histmap->idle_id) return fd->histmap; /* histmap exists and is finished */
 210
 211         return nullptr;
 212 }
 213
 214 static gboolean histmap_idle_cb(gpointer data)
 215 {
 216         auto fd = static_cast<FileData *>(data);
 217         if (histmap_read(fd->histmap, FALSE))
 218                 {
 219                 /* finished */
 220                 g_object_unref(fd->histmap->pixbuf); /*pixbuf is no longer needed */
 221                 fd->histmap->pixbuf = nullptr;
 222                 fd->histmap->idle_id = 0;
 223                 file_data_send_notification(fd, NOTIFY_HISTMAP);
 224                 return G_SOURCE_REMOVE;
 225                 }
 226         return G_SOURCE_CONTINUE;
 227 }
 228
 229 gboolean histmap_start_idle(FileData *fd)
 230 {
 231         if (fd->histmap || !fd->pixbuf) return FALSE;
 232
 233         fd->histmap = histmap_new();
 234         fd->histmap->pixbuf = fd->pixbuf;
 235         g_object_ref(fd->histmap->pixbuf);
 236
 237         fd->histmap->idle_id = g_idle_add_full(G_PRIORITY_DEFAULT_IDLE, histmap_idle_cb, fd, nullptr);
 238         return TRUE;
 239 }
 240
 241
 242 static void histogram_vgrid(Histogram *histogram, GdkPixbuf *pixbuf, gint x, gint y, gint width, gint height)
 243 {
 244         guint i;
 245         float add;
 246
 247         if (histogram->vgrid == 0) return;
 248
 249         add = width / static_cast<float>(histogram->vgrid);
 250
 251         for (i = 1; i < histogram->vgrid; i++)
 252                 {
 253                 gint xpos = x + static_cast<int>(i * add + 0.5);
 254
 255                 pixbuf_draw_line(pixbuf, x, y, width, height, xpos, y, xpos, y + height,
 256                                  histogram->grid_color.R,
 257                                  histogram->grid_color.G,
 258                                  histogram->grid_color.B,
 259                                  histogram->grid_color.A);
 260                 }
 261 }
 262
 263 static void histogram_hgrid(Histogram *histogram, GdkPixbuf *pixbuf, gint x, gint y, gint width, gint height)
 264 {
 265         guint i;
 266         float add;
 267
 268         if (histogram->hgrid == 0) return;
 269
 270         add = height / static_cast<float>(histogram->hgrid);
 271
 272         for (i = 1; i < histogram->hgrid; i++)
 273                 {
 274                 gint ypos = y + static_cast<int>(i * add + 0.5);
 275
 276                 pixbuf_draw_line(pixbuf, x, y, width, height, x, ypos, x + width, ypos,
 277                                  histogram->grid_color.R,
 278                                  histogram->grid_color.G,
 279                                  histogram->grid_color.B,
 280                                  histogram->grid_color.A);
 281                 }
 282 }
 283
 284 gboolean histogram_draw(Histogram *histogram, const HistMap *histmap, GdkPixbuf *pixbuf, gint x, gint y, gint width, gint height)
 285 {
 286         /** @FIXME use the coordinates correctly */
 287         gint i;
 288         gulong max = 0;
 289         gdouble logmax;
 290         gint combine = (HISTMAP_SIZE - 1) / width + 1;
 291         gint ypos = y + height;
 292
 293         if (!histogram || !histmap) return FALSE;
 294
 295         /* Draw the grid */
 296         histogram_vgrid(histogram, pixbuf, x, y, width, height);
 297         histogram_hgrid(histogram, pixbuf, x, y, width, height);
 298
 299         /* exclude overexposed and underexposed */
 300         for (i = 1; i < HISTMAP_SIZE - 1; i++)
 301                 {
 302                 if (histmap->r[i] > max) max = histmap->r[i];
 303                 if (histmap->g[i] > max) max = histmap->g[i];
 304                 if (histmap->b[i] > max) max = histmap->b[i];
 305                 if (histmap->max[i] > max) max = histmap->max[i];
 306                 }
 307
 308         if (max > 0)
 309                 logmax = log(max);
 310         else
 311                 logmax = 1.0;
 312
 313         for (i = 0; i < width; i++)
 314                 {
 315                 gint j;
 316                 glong v[4] = {0, 0, 0, 0};
 317                 gint rplus = 0;
 318                 gint gplus = 0;
 319                 gint bplus = 0;
 320                 gint ii = i * HISTMAP_SIZE / width;
 321                 gint xpos = x + i;
 322                 gint num_chan;
 323
 324                 for (j = 0; j < combine; j++)
 325                         {
 326                         guint p = ii + j;
 327                         v[0] += histmap->r[p];
 328                         v[1] += histmap->g[p];
 329                         v[2] += histmap->b[p];
 330                         v[3] += histmap->max[p];
 331                         }
 332
 333                 for (j = 0; combine > 1 && j < 4; j++)
 334                         v[j] /= combine;
 335
 336                 num_chan = (histogram->histogram_channel == HCHAN_RGB) ? 3 : 1;
 337                 for (j = 0; j < num_chan; j++)
 338                         {
 339                         gint chanmax;
 340                         if (histogram->histogram_channel == HCHAN_RGB)
 341                                 {
 342                                 chanmax = HCHAN_R;
 343                                 if (v[HCHAN_G] > v[HCHAN_R]) chanmax = HCHAN_G;
 344                                 if (v[HCHAN_B] > v[chanmax]) chanmax = HCHAN_B;
 345                                 }
 346                         else
 347                                 {
 348                                 chanmax = histogram->histogram_channel;
 349                                 }
 350
 351                                 {
 352                                 gulong pt;
 353                                 gint r = rplus;
 354                                 gint g = gplus;
 355                                 gint b = bplus;
 356
 357                                 switch (chanmax)
 358                                         {
 359                                         case HCHAN_R: rplus = r = 255; break;
 360                                         case HCHAN_G: gplus = g = 255; break;
 361                                         case HCHAN_B: bplus = b = 255; break;
 362                                         }
 363
 364                                 switch (histogram->histogram_channel)
 365                                         {
 366                                         case HCHAN_RGB:
 367                                                 if (r == 255 && g == 255 && b == 255)
 368                                                         {
 369                                                         r = 0;  b = 0;  g = 0;
 370                                                         }
 371                                                 break;
 372                                         case HCHAN_R:           b = 0;  g = 0;  break;
 373                                         case HCHAN_G:   r = 0;  b = 0;          break;
 374                                         case HCHAN_B:   r = 0;          g = 0;  break;
 375                                         case HCHAN_MAX: r = 0;  b = 0;  g = 0;  break;
 376                                         }
 377
 378                                 if (v[chanmax] == 0)
 379                                         pt = 0;
 380                                 else if (histogram->histogram_mode)
 381                                         pt = (static_cast<gdouble>(log(v[chanmax]))) / logmax * (height - 1);
 382                                 else
 383                                         pt = (static_cast<gdouble>(v[chanmax])) / max * (height - 1);
 384
 385                                 pixbuf_draw_line(pixbuf,
 386                                         x, y, width, height,
 387                                         xpos, ypos, xpos, ypos - pt,
 388                                         r, g, b, 255);
 389                                 }
 390
 391                         v[chanmax] = -1;
 392                         }
 393                 }
 394
 395         return TRUE;
 396 }
 397
 398 void histogram_notify_cb(FileData *fd, NotifyType type, gpointer)
 399 {
 400         if ((type & NOTIFY_REREAD) && fd->histmap)
 401                 {
 402                 DEBUG_1("Notify histogram: %s %04x", fd->path, type);
 403                 histmap_free(fd->histmap);
 404                 fd->histmap = nullptr;
 405                 }
 406 }
 407
 408 /* vim: set shiftwidth=8 softtabstop=0 cindent cinoptions={1s: */