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