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 "histogram.h"
  22
  23 #include <algorithm>
  24 #include <cmath>
  25
  26 #include <glib-object.h>
  27
  28 #include "debug.h"
  29 #include "filedata.h"
  30 #include "intl.h"
  31 #include "pixbuf-util.h"
  32
  33 /*
  34  *----------------------------------------------------------------------------
  35  * image histogram
  36  *----------------------------------------------------------------------------
  37  */
  38
  39 namespace
  40 {
  41
  42 constexpr gint HISTMAP_SIZE = 256;
  43
  44 } // namespace
  45
  46 struct HistMap {
  47         gulong r[HISTMAP_SIZE];
  48         gulong g[HISTMAP_SIZE];
  49         gulong b[HISTMAP_SIZE];
  50         gulong max[HISTMAP_SIZE];
  51
  52         guint idle_id; /* event source id */
  53         GdkPixbuf *pixbuf;
  54         gint y;
  55 };
  56
  57
  58 Histogram *histogram_new()
  59 {
  60         Histogram *histogram;
  61
  62         histogram = g_new0(Histogram, 1);
  63         histogram->histogram_channel = HCHAN_DEFAULT;
  64         histogram->histogram_mode = 0;
  65
  66         /* grid */
  67         histogram->vgrid = 5;
  68         histogram->hgrid = 3;
  69         histogram->grid_color.R = 160;
  70         histogram->grid_color.G = 160;
  71         histogram->grid_color.B = 160;
  72         histogram->grid_color.A = 250;
  73
  74         return histogram;
  75 }
  76
  77 void histogram_free(Histogram *histogram)
  78 {
  79         g_free(histogram);
  80 }
  81
  82
  83 gint histogram_set_channel(Histogram *histogram, gint chan)
  84 {
  85         if (!histogram) return 0;
  86         histogram->histogram_channel = chan;
  87         return chan;
  88 }
  89
  90 gint histogram_get_channel(Histogram *histogram)
  91 {
  92         if (!histogram) return 0;
  93         return histogram->histogram_channel;
  94 }
  95
  96 gint histogram_set_mode(Histogram *histogram, gint mode)
  97 {
  98         if (!histogram) return 0;
  99         histogram->histogram_mode = mode;
 100         return mode;
 101 }
 102
 103 gint histogram_get_mode(Histogram *histogram)
 104 {
 105         if (!histogram) return 0;
 106         return histogram->histogram_mode;
 107 }
 108
 109 gint histogram_toggle_channel(Histogram *histogram)
 110 {
 111         if (!histogram) return 0;
 112         return histogram_set_channel(histogram, (histogram_get_channel(histogram)+1)%HCHAN_COUNT);
 113 }
 114
 115 gint histogram_toggle_mode(Histogram *histogram)
 116 {
 117         if (!histogram) return 0;
 118         return histogram_set_mode(histogram, !histogram_get_mode(histogram));
 119 }
 120
 121 const gchar *histogram_label(Histogram *histogram)
 122 {
 123         const gchar *t1 = "";
 124
 125         if (!histogram) return nullptr;
 126
 127         if (histogram->histogram_mode)
 128                 switch (histogram->histogram_channel)
 129                         {
 130                         case HCHAN_R:   t1 = _("Log Histogram on Red"); break;
 131                         case HCHAN_G:   t1 = _("Log Histogram on Green"); break;
 132                         case HCHAN_B:   t1 = _("Log Histogram on Blue"); break;
 133                         case HCHAN_RGB: t1 = _("Log Histogram on RGB"); break;
 134                         case HCHAN_MAX: t1 = _("Log Histogram on value"); break;
 135                         default:
 136                                 break;
 137                         }
 138         else
 139                 switch (histogram->histogram_channel)
 140                         {
 141                         case HCHAN_R:   t1 = _("Linear Histogram on Red"); break;
 142                         case HCHAN_G:   t1 = _("Linear Histogram on Green"); break;
 143                         case HCHAN_B:   t1 = _("Linear Histogram on Blue"); break;
 144                         case HCHAN_RGB: t1 = _("Linear Histogram on RGB"); break;
 145                         case HCHAN_MAX: t1 = _("Linear Histogram on value"); break;
 146                         default:
 147                                 break;
 148                         }
 149         return t1;
 150 }
 151
 152 static HistMap *histmap_new()
 153 {
 154         auto histmap = g_new0(HistMap, 1);
 155         return histmap;
 156 }
 157
 158 void histmap_free(HistMap *histmap)
 159 {
 160         if (!histmap) return;
 161         if (histmap->idle_id) g_source_remove(histmap->idle_id);
 162         if (histmap->pixbuf) g_object_unref(histmap->pixbuf);
 163         g_free(histmap);
 164 }
 165
 166 static gboolean histmap_read(HistMap *histmap, gboolean whole)
 167 {
 168         gint w;
 169         gint h;
 170         gint i;
 171         gint j;
 172         gint srs;
 173         gint has_alpha;
 174         gint step;
 175         gint end_line;
 176         guchar *s_pix;
 177         GdkPixbuf *imgpixbuf = histmap->pixbuf;
 178
 179         w = gdk_pixbuf_get_width(imgpixbuf);
 180         h = gdk_pixbuf_get_height(imgpixbuf);
 181         srs = gdk_pixbuf_get_rowstride(imgpixbuf);
 182         s_pix = gdk_pixbuf_get_pixels(imgpixbuf);
 183         has_alpha = gdk_pixbuf_get_has_alpha(imgpixbuf);
 184
 185         if (whole)
 186                 {
 187                 end_line = h;
 188                 }
 189         else
 190                 {
 191                 gint lines = 1 + 16384 / w;
 192                 end_line = histmap->y + lines;
 193                 if (end_line > h) end_line = h;
 194                 }
 195
 196         step = 3 + !!(has_alpha);
 197         for (i = histmap->y; i < end_line; i++)
 198                 {
 199                 guchar *sp = s_pix + (i * srs); /* 8bit */
 200                 for (j = 0; j < w; j++)
 201                         {
 202                         guint max = std::max({sp[0], sp[1], sp[2]});
 203
 204                         histmap->r[sp[0]]++;
 205                         histmap->g[sp[1]]++;
 206                         histmap->b[sp[2]]++;
 207                         histmap->max[max]++;
 208
 209                         sp += step;
 210                         }
 211                 }
 212         histmap->y = end_line;
 213         return end_line >= h;
 214 }
 215
 216 const HistMap *histmap_get(FileData *fd)
 217 {
 218         if (fd->histmap && !fd->histmap->idle_id) return fd->histmap; /* histmap exists and is finished */
 219
 220         return nullptr;
 221 }
 222
 223 static gboolean histmap_idle_cb(gpointer data)
 224 {
 225         auto fd = static_cast<FileData *>(data);
 226         if (histmap_read(fd->histmap, FALSE))
 227                 {
 228                 /* finished */
 229                 g_object_unref(fd->histmap->pixbuf); /*pixbuf is no longer needed */
 230                 fd->histmap->pixbuf = nullptr;
 231                 fd->histmap->idle_id = 0;
 232                 file_data_send_notification(fd, NOTIFY_HISTMAP);
 233                 return G_SOURCE_REMOVE;
 234                 }
 235         return G_SOURCE_CONTINUE;
 236 }
 237
 238 gboolean histmap_start_idle(FileData *fd)
 239 {
 240         if (fd->histmap || !fd->pixbuf) return FALSE;
 241
 242         fd->histmap = histmap_new();
 243         fd->histmap->pixbuf = fd->pixbuf;
 244         g_object_ref(fd->histmap->pixbuf);
 245
 246         fd->histmap->idle_id = g_idle_add_full(G_PRIORITY_DEFAULT_IDLE, histmap_idle_cb, fd, nullptr);
 247         return TRUE;
 248 }
 249
 250
 251 static void histogram_vgrid(Histogram *histogram, GdkPixbuf *pixbuf, gint x, gint y, gint width, gint height)
 252 {
 253         guint i;
 254         float add;
 255
 256         if (histogram->vgrid == 0) return;
 257
 258         add = width / static_cast<float>(histogram->vgrid);
 259
 260         for (i = 1; i < histogram->vgrid; i++)
 261                 {
 262                 gint xpos = x + static_cast<int>(i * add + 0.5);
 263
 264                 pixbuf_draw_line(pixbuf, x, y, width, height, xpos, y, xpos, y + height,
 265                                  histogram->grid_color.R,
 266                                  histogram->grid_color.G,
 267                                  histogram->grid_color.B,
 268                                  histogram->grid_color.A);
 269                 }
 270 }
 271
 272 static void histogram_hgrid(Histogram *histogram, GdkPixbuf *pixbuf, gint x, gint y, gint width, gint height)
 273 {
 274         guint i;
 275         float add;
 276
 277         if (histogram->hgrid == 0) return;
 278
 279         add = height / static_cast<float>(histogram->hgrid);
 280
 281         for (i = 1; i < histogram->hgrid; i++)
 282                 {
 283                 gint ypos = y + static_cast<int>(i * add + 0.5);
 284
 285                 pixbuf_draw_line(pixbuf, x, y, width, height, x, ypos, x + width, ypos,
 286                                  histogram->grid_color.R,
 287                                  histogram->grid_color.G,
 288                                  histogram->grid_color.B,
 289                                  histogram->grid_color.A);
 290                 }
 291 }
 292
 293 gboolean histogram_draw(Histogram *histogram, const HistMap *histmap, GdkPixbuf *pixbuf, gint x, gint y, gint width, gint height)
 294 {
 295         /** @FIXME use the coordinates correctly */
 296         gint i;
 297         gulong max = 0;
 298         gdouble logmax;
 299         gint combine = (HISTMAP_SIZE - 1) / width + 1;
 300         gint ypos = y + height;
 301
 302         if (!histogram || !histmap) return FALSE;
 303
 304         /* Draw the grid */
 305         histogram_vgrid(histogram, pixbuf, x, y, width, height);
 306         histogram_hgrid(histogram, pixbuf, x, y, width, height);
 307
 308         /* exclude overexposed and underexposed */
 309         for (i = 1; i < HISTMAP_SIZE - 1; i++)
 310                 {
 311                 max = std::max({histmap->r[i], histmap->g[i], histmap->b[i], histmap->max[i], max});
 312                 }
 313
 314         if (max > 0)
 315                 logmax = log(max);
 316         else
 317                 logmax = 1.0;
 318
 319         for (i = 0; i < width; i++)
 320                 {
 321                 gint j;
 322                 glong v[4] = {0, 0, 0, 0};
 323                 gint rplus = 0;
 324                 gint gplus = 0;
 325                 gint bplus = 0;
 326                 gint ii = i * HISTMAP_SIZE / width;
 327                 gint xpos = x + i;
 328                 gint num_chan;
 329
 330                 for (j = 0; j < combine; j++)
 331                         {
 332                         guint p = ii + j;
 333                         v[0] += histmap->r[p];
 334                         v[1] += histmap->g[p];
 335                         v[2] += histmap->b[p];
 336                         v[3] += histmap->max[p];
 337                         }
 338
 339                 for (j = 0; combine > 1 && j < 4; j++)
 340                         v[j] /= combine;
 341
 342                 num_chan = (histogram->histogram_channel == HCHAN_RGB) ? 3 : 1;
 343                 for (j = 0; j < num_chan; j++)
 344                         {
 345                         gint chanmax;
 346                         if (histogram->histogram_channel == HCHAN_RGB)
 347                                 {
 348                                 chanmax = HCHAN_R;
 349                                 if (v[HCHAN_G] > v[HCHAN_R]) chanmax = HCHAN_G;
 350                                 if (v[HCHAN_B] > v[chanmax]) chanmax = HCHAN_B;
 351                                 }
 352                         else
 353                                 {
 354                                 chanmax = histogram->histogram_channel;
 355                                 }
 356
 357                                 {
 358                                 gulong pt;
 359                                 gint r = rplus;
 360                                 gint g = gplus;
 361                                 gint b = bplus;
 362
 363                                 switch (chanmax)
 364                                         {
 365                                         case HCHAN_R: rplus = r = 255; break;
 366                                         case HCHAN_G: gplus = g = 255; break;
 367                                         case HCHAN_B: bplus = b = 255; break;
 368                                         default:
 369                                                 break;
 370                                         }
 371
 372                                 switch (histogram->histogram_channel)
 373                                         {
 374                                         case HCHAN_RGB:
 375                                                 if (r == 255 && g == 255 && b == 255)
 376                                                         {
 377                                                         r = 0;  b = 0;  g = 0;
 378                                                         }
 379                                                 break;
 380                                         case HCHAN_R:           b = 0;  g = 0;  break;
 381                                         case HCHAN_G:   r = 0;  b = 0;          break;
 382                                         case HCHAN_B:   r = 0;          g = 0;  break;
 383                                         case HCHAN_MAX: r = 0;  b = 0;  g = 0;  break;
 384                                         default:
 385                                                 break;
 386                                         }
 387
 388                                 if (v[chanmax] == 0)
 389                                         pt = 0;
 390                                 else if (histogram->histogram_mode)
 391                                         pt = (static_cast<gdouble>(log(v[chanmax]))) / logmax * (height - 1);
 392                                 else
 393                                         pt = (static_cast<gdouble>(v[chanmax])) / max * (height - 1);
 394
 395                                 pixbuf_draw_line(pixbuf,
 396                                         x, y, width, height,
 397                                         xpos, ypos, xpos, ypos - pt,
 398                                         r, g, b, 255);
 399                                 }
 400
 401                         v[chanmax] = -1;
 402                         }
 403                 }
 404
 405         return TRUE;
 406 }
 407
 408 void histogram_notify_cb(FileData *fd, NotifyType type, gpointer)
 409 {
 410         if ((type & NOTIFY_REREAD) && fd->histmap)
 411                 {
 412                 DEBUG_1("Notify histogram: %s %04x", fd->path, type);
 413                 histmap_free(fd->histmap);
 414                 fd->histmap = nullptr;
 415                 }
 416 }
 417
 418 /* vim: set shiftwidth=8 softtabstop=0 cindent cinoptions={1s: */