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, h, i, j, srs, has_alpha, step, end_line;
 158         guchar *s_pix;
 159         GdkPixbuf *imgpixbuf = histmap->pixbuf;
 160
 161         w = gdk_pixbuf_get_width(imgpixbuf);
 162         h = gdk_pixbuf_get_height(imgpixbuf);
 163         srs = gdk_pixbuf_get_rowstride(imgpixbuf);
 164         s_pix = gdk_pixbuf_get_pixels(imgpixbuf);
 165         has_alpha = gdk_pixbuf_get_has_alpha(imgpixbuf);
 166
 167         if (whole)
 168                 {
 169                 end_line = h;
 170                 }
 171         else
 172                 {
 173                 gint lines = 1 + 16384 / w;
 174                 end_line = histmap->y + lines;
 175                 if (end_line > h) end_line = h;
 176                 }
 177
 178         step = 3 + !!(has_alpha);
 179         for (i = histmap->y; i < end_line; i++)
 180                 {
 181                 guchar *sp = s_pix + (i * srs); /* 8bit */
 182                 for (j = 0; j < w; j++)
 183                         {
 184                         guint max = sp[0];
 185                         if (sp[1] > max) max = sp[1];
 186                         if (sp[2] > max) max = sp[2];
 187
 188                         histmap->r[sp[0]]++;
 189                         histmap->g[sp[1]]++;
 190                         histmap->b[sp[2]]++;
 191                         histmap->max[max]++;
 192
 193                         sp += step;
 194                         }
 195                 }
 196         histmap->y = end_line;
 197         return end_line >= h;
 198 }
 199
 200 const HistMap *histmap_get(FileData *fd)
 201 {
 202         if (fd->histmap && !fd->histmap->idle_id) return fd->histmap; /* histmap exists and is finished */
 203
 204         return nullptr;
 205 }
 206
 207 static gboolean histmap_idle_cb(gpointer data)
 208 {
 209         auto fd = static_cast<FileData *>(data);
 210         if (histmap_read(fd->histmap, FALSE))
 211                 {
 212                 /* finished */
 213                 g_object_unref(fd->histmap->pixbuf); /*pixbuf is no longer needed */
 214                 fd->histmap->pixbuf = nullptr;
 215                 fd->histmap->idle_id = 0;
 216                 file_data_send_notification(fd, NOTIFY_HISTMAP);
 217                 return G_SOURCE_REMOVE;
 218                 }
 219         return G_SOURCE_CONTINUE;
 220 }
 221
 222 gboolean histmap_start_idle(FileData *fd)
 223 {
 224         if (fd->histmap || !fd->pixbuf) return FALSE;
 225
 226         fd->histmap = histmap_new();
 227         fd->histmap->pixbuf = fd->pixbuf;
 228         g_object_ref(fd->histmap->pixbuf);
 229
 230         fd->histmap->idle_id = g_idle_add_full(G_PRIORITY_DEFAULT_IDLE, histmap_idle_cb, fd, nullptr);
 231         return TRUE;
 232 }
 233
 234
 235 static void histogram_vgrid(Histogram *histogram, GdkPixbuf *pixbuf, gint x, gint y, gint width, gint height)
 236 {
 237         guint i;
 238         float add;
 239
 240         if (histogram->vgrid == 0) return;
 241
 242         add = width / static_cast<float>(histogram->vgrid);
 243
 244         for (i = 1; i < histogram->vgrid; i++)
 245                 {
 246                 gint xpos = x + static_cast<int>(i * add + 0.5);
 247
 248                 pixbuf_draw_line(pixbuf, x, y, width, height, xpos, y, xpos, y + height,
 249                                  histogram->grid_color.R,
 250                                  histogram->grid_color.G,
 251                                  histogram->grid_color.B,
 252                                  histogram->grid_color.A);
 253                 }
 254 }
 255
 256 static void histogram_hgrid(Histogram *histogram, GdkPixbuf *pixbuf, gint x, gint y, gint width, gint height)
 257 {
 258         guint i;
 259         float add;
 260
 261         if (histogram->hgrid == 0) return;
 262
 263         add = height / static_cast<float>(histogram->hgrid);
 264
 265         for (i = 1; i < histogram->hgrid; i++)
 266                 {
 267                 gint ypos = y + static_cast<int>(i * add + 0.5);
 268
 269                 pixbuf_draw_line(pixbuf, x, y, width, height, x, ypos, x + width, ypos,
 270                                  histogram->grid_color.R,
 271                                  histogram->grid_color.G,
 272                                  histogram->grid_color.B,
 273                                  histogram->grid_color.A);
 274                 }
 275 }
 276
 277 gboolean histogram_draw(Histogram *histogram, const HistMap *histmap, GdkPixbuf *pixbuf, gint x, gint y, gint width, gint height)
 278 {
 279         /** @FIXME use the coordinates correctly */
 280         gint i;
 281         gulong max = 0;
 282         gdouble logmax;
 283         gint combine = (HISTMAP_SIZE - 1) / width + 1;
 284         gint ypos = y + height;
 285
 286         if (!histogram || !histmap) return FALSE;
 287
 288         /* Draw the grid */
 289         histogram_vgrid(histogram, pixbuf, x, y, width, height);
 290         histogram_hgrid(histogram, pixbuf, x, y, width, height);
 291
 292         /* exclude overexposed and underexposed */
 293         for (i = 1; i < HISTMAP_SIZE - 1; i++)
 294                 {
 295                 if (histmap->r[i] > max) max = histmap->r[i];
 296                 if (histmap->g[i] > max) max = histmap->g[i];
 297                 if (histmap->b[i] > max) max = histmap->b[i];
 298                 if (histmap->max[i] > max) max = histmap->max[i];
 299                 }
 300
 301         if (max > 0)
 302                 logmax = log(max);
 303         else
 304                 logmax = 1.0;
 305
 306         for (i = 0; i < width; i++)
 307                 {
 308                 gint j;
 309                 glong v[4] = {0, 0, 0, 0};
 310                 gint rplus = 0;
 311                 gint gplus = 0;
 312                 gint bplus = 0;
 313                 gint ii = i * HISTMAP_SIZE / width;
 314                 gint xpos = x + i;
 315                 gint num_chan;
 316
 317                 for (j = 0; j < combine; j++)
 318                         {
 319                         guint p = ii + j;
 320                         v[0] += histmap->r[p];
 321                         v[1] += histmap->g[p];
 322                         v[2] += histmap->b[p];
 323                         v[3] += histmap->max[p];
 324                         }
 325
 326                 for (j = 0; combine > 1 && j < 4; j++)
 327                         v[j] /= combine;
 328
 329                 num_chan = (histogram->histogram_channel == HCHAN_RGB) ? 3 : 1;
 330                 for (j = 0; j < num_chan; j++)
 331                         {
 332                         gint chanmax;
 333                         if (histogram->histogram_channel == HCHAN_RGB)
 334                                 {
 335                                 chanmax = HCHAN_R;
 336                                 if (v[HCHAN_G] > v[HCHAN_R]) chanmax = HCHAN_G;
 337                                 if (v[HCHAN_B] > v[chanmax]) chanmax = HCHAN_B;
 338                                 }
 339                         else
 340                                 {
 341                                 chanmax = histogram->histogram_channel;
 342                                 }
 343
 344                                 {
 345                                 gulong pt;
 346                                 gint r = rplus;
 347                                 gint g = gplus;
 348                                 gint b = bplus;
 349
 350                                 switch (chanmax)
 351                                         {
 352                                         case HCHAN_R: rplus = r = 255; break;
 353                                         case HCHAN_G: gplus = g = 255; break;
 354                                         case HCHAN_B: bplus = b = 255; break;
 355                                         }
 356
 357                                 switch (histogram->histogram_channel)
 358                                         {
 359                                         case HCHAN_RGB:
 360                                                 if (r == 255 && g == 255 && b == 255)
 361                                                         {
 362                                                         r = 0;  b = 0;  g = 0;
 363                                                         }
 364                                                 break;
 365                                         case HCHAN_R:           b = 0;  g = 0;  break;
 366                                         case HCHAN_G:   r = 0;  b = 0;          break;
 367                                         case HCHAN_B:   r = 0;          g = 0;  break;
 368                                         case HCHAN_MAX: r = 0;  b = 0;  g = 0;  break;
 369                                         }
 370
 371                                 if (v[chanmax] == 0)
 372                                         pt = 0;
 373                                 else if (histogram->histogram_mode)
 374                                         pt = (static_cast<gdouble>(log(v[chanmax]))) / logmax * (height - 1);
 375                                 else
 376                                         pt = (static_cast<gdouble>(v[chanmax])) / max * (height - 1);
 377
 378                                 pixbuf_draw_line(pixbuf,
 379                                         x, y, width, height,
 380                                         xpos, ypos, xpos, ypos - pt,
 381                                         r, g, b, 255);
 382                                 }
 383
 384                         v[chanmax] = -1;
 385                         }
 386                 }
 387
 388         return TRUE;
 389 }
 390
 391 void histogram_notify_cb(FileData *fd, NotifyType type, gpointer)
 392 {
 393         if ((type & NOTIFY_REREAD) && fd->histmap)
 394                 {
 395                 DEBUG_1("Notify histogram: %s %04x", fd->path, type);
 396                 histmap_free(fd->histmap);
 397                 fd->histmap = nullptr;
 398                 }
 399 }
 400
 401 /* vim: set shiftwidth=8 softtabstop=0 cindent cinoptions={1s: */