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