src/histogram.c

   1 /*
   2  * Geeqie
   3  * Copyright (C) 2008 - 2009 The Geeqie Team
   4  *
   5  * Author: Vladimir Nadvornik
   6  * based on a patch by Uwe Ohse
   7  *
   8  * This software is released under the GNU General Public License (GNU GPL).
   9  * Please read the included file COPYING for more information.
  10  * This software comes with no warranty of any kind, use at your own risk!
  11  */
  12
  13 #include "main.h"
  14 #include "histogram.h"
  15
  16 #include "pixbuf_util.h"
  17 #include "filedata.h"
  18
  19 #include <math.h>
  20
  21 /*
  22  *----------------------------------------------------------------------------
  23  * image histogram
  24  *----------------------------------------------------------------------------
  25  */
  26
  27 #define HISTMAP_SIZE 256
  28
  29 struct _HistMap {
  30         gulong r[HISTMAP_SIZE];
  31         gulong g[HISTMAP_SIZE];
  32         gulong b[HISTMAP_SIZE];
  33         gulong max[HISTMAP_SIZE];
  34
  35         gint idle_id;
  36         GdkPixbuf *pixbuf;
  37         gint y;
  38 };
  39
  40
  41 Histogram *histogram_new(void)
  42 {
  43         Histogram *histogram;
  44
  45         histogram = g_new0(Histogram, 1);
  46         histogram->histogram_channel = HCHAN_RGB;
  47         histogram->histogram_mode = 0;
  48
  49         /* grid */
  50         histogram->vgrid = 5;
  51         histogram->hgrid = 3;
  52         histogram->grid_color.R = 160;
  53         histogram->grid_color.G = 160;
  54         histogram->grid_color.B = 160;
  55         histogram->grid_color.A = 250;
  56
  57         return histogram;
  58 }
  59
  60 void histogram_free(Histogram *histogram)
  61 {
  62         g_free(histogram);
  63 }
  64
  65
  66 gint histogram_set_channel(Histogram *histogram, gint chan)
  67 {
  68         if (!histogram) return 0;
  69         histogram->histogram_channel = chan;
  70         return chan;
  71 }
  72
  73 gint histogram_get_channel(Histogram *histogram)
  74 {
  75         if (!histogram) return 0;
  76         return histogram->histogram_channel;
  77 }
  78
  79 gint histogram_set_mode(Histogram *histogram, gint mode)
  80 {
  81         if (!histogram) return 0;
  82         histogram->histogram_mode = mode;
  83         return mode;
  84 }
  85
  86 gint histogram_get_mode(Histogram *histogram)
  87 {
  88         if (!histogram) return 0;
  89         return histogram->histogram_mode;
  90 }
  91
  92 gint histogram_toggle_channel(Histogram *histogram)
  93 {
  94         if (!histogram) return 0;
  95         return histogram_set_channel(histogram, (histogram_get_channel(histogram)+1)%HCHAN_COUNT);
  96 }
  97
  98 gint histogram_toggle_mode(Histogram *histogram)
  99 {
 100         if (!histogram) return 0;
 101         return histogram_set_mode(histogram, !histogram_get_mode(histogram));
 102 }
 103
 104 const gchar *histogram_label(Histogram *histogram)
 105 {
 106         const gchar *t1 = "";
 107
 108         if (!histogram) return NULL;
 109
 110         if (histogram->histogram_mode)
 111                 switch (histogram->histogram_channel)
 112                         {
 113                         case HCHAN_R:   t1 = _("Log Histogram on Red"); break;
 114                         case HCHAN_G:   t1 = _("Log Histogram on Green"); break;
 115                         case HCHAN_B:   t1 = _("Log Histogram on Blue"); break;
 116                         case HCHAN_RGB: t1 = _("Log Histogram on RGB"); break;
 117                         case HCHAN_MAX: t1 = _("Log Histogram on value"); break;
 118                         }
 119         else
 120                 switch (histogram->histogram_channel)
 121                         {
 122                         case HCHAN_R:   t1 = _("Linear Histogram on Red"); break;
 123                         case HCHAN_G:   t1 = _("Linear Histogram on Green"); break;
 124                         case HCHAN_B:   t1 = _("Linear Histogram on Blue"); break;
 125                         case HCHAN_RGB: t1 = _("Linear Histogram on RGB"); break;
 126                         case HCHAN_MAX: t1 = _("Linear Histogram on value"); break;
 127                         }
 128         return t1;
 129 }
 130
 131 static HistMap *histmap_new(void)
 132 {
 133         HistMap *histmap = g_new0(HistMap, 1);
 134         histmap->idle_id = -1;
 135         return histmap;
 136 }
 137
 138 void histmap_free(HistMap *histmap)
 139 {
 140         if (!histmap) return;
 141         if (histmap->idle_id != -1) g_source_remove(histmap->idle_id);
 142         if (histmap->pixbuf) g_object_unref(histmap->pixbuf);
 143         g_free(histmap);
 144 }
 145
 146 static gboolean histmap_read(HistMap *histmap, gboolean whole)
 147 {
 148         gint w, h, i, j, srs, has_alpha, step, end_line;
 149         guchar *s_pix;
 150         GdkPixbuf *imgpixbuf = histmap->pixbuf;
 151
 152         w = gdk_pixbuf_get_width(imgpixbuf);
 153         h = gdk_pixbuf_get_height(imgpixbuf);
 154         srs = gdk_pixbuf_get_rowstride(imgpixbuf);
 155         s_pix = gdk_pixbuf_get_pixels(imgpixbuf);
 156         has_alpha = gdk_pixbuf_get_has_alpha(imgpixbuf);
 157
 158         if (whole)
 159                 {
 160                 end_line = h;
 161                 }
 162         else
 163                 {
 164                 gint lines = 1 + 16384 / w;
 165                 end_line = histmap->y + lines;
 166                 if (end_line > h) end_line = h;
 167                 }
 168
 169         step = 3 + !!(has_alpha);
 170         for (i = histmap->y; i < end_line; i++)
 171                 {
 172                 guchar *sp = s_pix + (i * srs); /* 8bit */
 173                 for (j = 0; j < w; j++)
 174                         {
 175                         guint max = sp[0];
 176                         if (sp[1] > max) max = sp[1];
 177                         if (sp[2] > max) max = sp[2];
 178
 179                         histmap->r[sp[0]]++;
 180                         histmap->g[sp[1]]++;
 181                         histmap->b[sp[2]]++;
 182                         histmap->max[max]++;
 183
 184                         sp += step;
 185                         }
 186                 }
 187         histmap->y = end_line;
 188         return end_line >= h;
 189 }
 190
 191 const HistMap *histmap_get(FileData *fd)
 192 {
 193         if (fd->histmap && fd->histmap->idle_id == -1) return fd->histmap; /* histmap exists and is finished */
 194
 195         return NULL;
 196 }
 197
 198 static gboolean histmap_idle_cb(gpointer data)
 199 {
 200         FileData *fd = data;
 201         if (histmap_read(fd->histmap, FALSE))
 202                 {
 203                 /* finished */
 204                 g_object_unref(fd->histmap->pixbuf); /*pixbuf is no longer needed */
 205                 fd->histmap->pixbuf = NULL;
 206                 fd->histmap->idle_id = -1;
 207                 file_data_send_notification(fd, NOTIFY_HISTMAP);
 208                 return FALSE;
 209                 }
 210         return TRUE;
 211 }
 212
 213 gboolean histmap_start_idle(FileData *fd)
 214 {
 215         if (fd->histmap || !fd->pixbuf) return FALSE;
 216
 217         fd->histmap = histmap_new();
 218         fd->histmap->pixbuf = fd->pixbuf;
 219         g_object_ref(fd->histmap->pixbuf);
 220
 221         fd->histmap->idle_id = g_idle_add_full(G_PRIORITY_DEFAULT_IDLE, histmap_idle_cb, fd, NULL);
 222         return TRUE;
 223 }
 224
 225
 226 static void histogram_vgrid(Histogram *histogram, GdkPixbuf *pixbuf, gint x, gint y, gint width, gint height)
 227 {
 228         guint i;
 229         float add;
 230
 231         if (histogram->vgrid == 0) return;
 232
 233         add = width / (float)histogram->vgrid;
 234
 235         for (i = 1; i < histogram->vgrid; i++)
 236                 {
 237                 gint xpos = x + (int)(i * add + 0.5);
 238
 239                 pixbuf_draw_line(pixbuf, x, y, width, height, xpos, y, xpos, y + height,
 240                                  histogram->grid_color.R,
 241                                  histogram->grid_color.G,
 242                                  histogram->grid_color.B,
 243                                  histogram->grid_color.A);
 244                 }
 245 }
 246
 247 static void histogram_hgrid(Histogram *histogram, GdkPixbuf *pixbuf, gint x, gint y, gint width, gint height)
 248 {
 249         guint i;
 250         float add;
 251
 252         if (histogram->hgrid == 0) return;
 253
 254         add = height / (float)histogram->hgrid;
 255
 256         for (i = 1; i < histogram->hgrid; i++)
 257                 {
 258                 gint ypos = y + (int)(i * add + 0.5);
 259
 260                 pixbuf_draw_line(pixbuf, x, y, width, height, x, ypos, x + width, ypos,
 261                                  histogram->grid_color.R,
 262                                  histogram->grid_color.G,
 263                                  histogram->grid_color.B,
 264                                  histogram->grid_color.A);
 265                 }
 266 }
 267
 268 gboolean histogram_draw(Histogram *histogram, const HistMap *histmap, GdkPixbuf *pixbuf, gint x, gint y, gint width, gint height)
 269 {
 270         /* FIXME: use the coordinates correctly */
 271         gint i;
 272         gulong max = 0;
 273         gdouble logmax;
 274         gint combine = (HISTMAP_SIZE - 1) / width + 1;
 275         gint ypos = y + height;
 276
 277         if (!histogram || !histmap) return FALSE;
 278
 279         /* Draw the grid */
 280         histogram_vgrid(histogram, pixbuf, x, y, width, height);
 281         histogram_hgrid(histogram, pixbuf, x, y, width, height);
 282
 283         /* exclude overexposed and underexposed */
 284         for (i = 1; i < HISTMAP_SIZE - 1; i++)
 285                 {
 286                 if (histmap->r[i] > max) max = histmap->r[i];
 287                 if (histmap->g[i] > max) max = histmap->g[i];
 288                 if (histmap->b[i] > max) max = histmap->b[i];
 289                 if (histmap->max[i] > max) max = histmap->max[i];
 290                 }
 291
 292         if (max > 0)
 293                 logmax = log(max);
 294         else
 295                 logmax = 1.0;
 296
 297         for (i = 0; i < width; i++)
 298                 {
 299                 gint j;
 300                 glong v[4] = {0, 0, 0, 0};
 301                 gint rplus = 0;
 302                 gint gplus = 0;
 303                 gint bplus = 0;
 304                 gint ii = i * HISTMAP_SIZE / width;
 305                 gint xpos = x + i;
 306                 gint num_chan;
 307
 308                 for (j = 0; j < combine; j++)
 309                         {
 310                         guint p = ii + j;
 311                         v[0] += histmap->r[p];
 312                         v[1] += histmap->g[p];
 313                         v[2] += histmap->b[p];
 314                         v[3] += histmap->max[p];
 315                         }
 316
 317                 for (j = 0; combine > 1 && j < 4; j++)
 318                         v[j] /= combine;
 319
 320                 num_chan = (histogram->histogram_channel == HCHAN_RGB) ? 3 : 1;
 321                 for (j = 0; j < num_chan; j++)
 322                         {
 323                         gint chanmax;
 324                         if (histogram->histogram_channel == HCHAN_RGB)
 325                                 {
 326                                 chanmax = HCHAN_R;
 327                                 if (v[HCHAN_G] > v[HCHAN_R]) chanmax = HCHAN_G;
 328                                 if (v[HCHAN_B] > v[chanmax]) chanmax = HCHAN_B;
 329                                 }
 330                         else
 331                                 {
 332                                 chanmax = histogram->histogram_channel;
 333                                 }
 334
 335                                 {
 336                                 gulong pt;
 337                                 gint r = rplus;
 338                                 gint g = gplus;
 339                                 gint b = bplus;
 340
 341                                 switch (chanmax)
 342                                         {
 343                                         case HCHAN_R: rplus = r = 255; break;
 344                                         case HCHAN_G: gplus = g = 255; break;
 345                                         case HCHAN_B: bplus = b = 255; break;
 346                                         }
 347
 348                                 switch (histogram->histogram_channel)
 349                                         {
 350                                         case HCHAN_RGB:
 351                                                 if (r == 255 && g == 255 && b == 255)
 352                                                         {
 353                                                         r = 0;  b = 0;  g = 0;
 354                                                         }
 355                                                 break;
 356                                         case HCHAN_R:           b = 0;  g = 0;  break;
 357                                         case HCHAN_G:   r = 0;  b = 0;          break;
 358                                         case HCHAN_B:   r = 0;          g = 0;  break;
 359                                         case HCHAN_MAX: r = 0;  b = 0;  g = 0;  break;
 360                                         }
 361
 362                                 if (v[chanmax] == 0)
 363                                         pt = 0;
 364                                 else if (histogram->histogram_mode)
 365                                         pt = ((gdouble)log(v[chanmax])) / logmax * (height - 1);
 366                                 else
 367                                         pt = ((gdouble)v[chanmax]) / max * (height - 1);
 368
 369                                 pixbuf_draw_line(pixbuf,
 370                                         x, y, width, height,
 371                                         xpos, ypos, xpos, ypos - pt,
 372                                         r, g, b, 255);
 373                                 }
 374
 375                         v[chanmax] = -1;
 376                         }
 377                 }
 378
 379         return TRUE;
 380 }
 381
 382 void histogram_notify_cb(FileData *fd, NotifyType type, gpointer data)
 383 {
 384         if ((type & (NOTIFY_CHANGE | NOTIFY_REREAD)) && fd->histmap)
 385                 {
 386                 DEBUG_1("Notify histogram: %s %04x", fd->path, type);
 387                 histmap_free(fd->histmap);
 388                 fd->histmap = NULL;
 389                 }
 390 }
 391
 392 /* vim: set shiftwidth=8 softtabstop=0 cindent cinoptions={1s: */