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
  18 #include <math.h>
  19
  20 /*
  21  *----------------------------------------------------------------------------
  22  * image histogram
  23  *----------------------------------------------------------------------------
  24  */
  25
  26 #define HISTMAP_SIZE 256
  27 typedef enum {
  28         HISTMAP_CHANNEL_R = 0,
  29         HISTMAP_CHANNEL_G,
  30         HISTMAP_CHANNEL_B,
  31         HISTMAP_CHANNEL_AVG,
  32         HISTMAP_CHANNEL_MAX,
  33         HISTMAP_CHANNELS
  34 } HistMapChannels;
  35
  36 struct _HistMap {
  37         gulong histmap[HISTMAP_SIZE * HISTMAP_CHANNELS];
  38         gulong area;
  39 };
  40
  41 struct _Histogram {
  42         gint channel_mode; /* drawing mode for histogram */
  43         gint log_mode;     /* logarithmical or not */
  44         guint vgrid; /* number of vertical divisions, 0 for none */
  45         guint hgrid; /* number of horizontal divisions, 0 for none */
  46         struct {
  47                 int R; /* red */
  48                 int G; /* green */
  49                 int B; /* blue */
  50                 int A; /* alpha */
  51         } grid_color;  /* grid color */
  52
  53 };
  54
  55 Histogram *histogram_new(void)
  56 {
  57         Histogram *histogram;
  58
  59         histogram = g_new0(Histogram, 1);
  60         histogram->channel_mode = options->histogram.last_channel_mode;
  61         histogram->log_mode = options->histogram.last_log_mode;
  62
  63         /* grid */
  64         histogram->vgrid = 5;
  65         histogram->hgrid = 3;
  66         histogram->grid_color.R = 160;
  67         histogram->grid_color.G = 160;
  68         histogram->grid_color.B = 160;
  69         histogram->grid_color.A = 250;
  70
  71         return histogram;
  72 }
  73
  74 void histogram_free(Histogram *histogram)
  75 {
  76         g_free(histogram);
  77 }
  78
  79
  80 gint histogram_set_channel(Histogram *histogram, gint chan)
  81 {
  82         if (!histogram) return 0;
  83         options->histogram.last_channel_mode = histogram->channel_mode = chan;
  84         return chan;
  85 }
  86
  87 gint histogram_get_channel(Histogram *histogram)
  88 {
  89         if (!histogram) return 0;
  90         return histogram->channel_mode;
  91 }
  92
  93 gint histogram_set_mode(Histogram *histogram, gint mode)
  94 {
  95         if (!histogram) return 0;
  96         options->histogram.last_log_mode = histogram->log_mode = mode;
  97         return mode;
  98 }
  99
 100 gint histogram_get_mode(Histogram *histogram)
 101 {
 102         if (!histogram) return 0;
 103         return histogram->log_mode;
 104 }
 105
 106 const gchar *histogram_label(Histogram *histogram)
 107 {
 108         const gchar *t1 = "";
 109
 110         if (!histogram) return NULL;
 111
 112         if (histogram->log_mode)
 113                 switch (histogram->channel_mode)
 114                         {
 115                         case HCHAN_R:   t1 = _("logarithmical histogram on red"); break;
 116                         case HCHAN_G:   t1 = _("logarithmical histogram on green"); break;
 117                         case HCHAN_B:   t1 = _("logarithmical histogram on blue"); break;
 118                         case HCHAN_VAL: t1 = _("logarithmical histogram on value"); break;
 119                         case HCHAN_RGB: t1 = _("logarithmical histogram on RGB"); break;
 120                         case HCHAN_MAX: t1 = _("logarithmical histogram on max value"); break;
 121                         }
 122         else
 123                 switch (histogram->channel_mode)
 124                         {
 125                         case HCHAN_R:   t1 = _("linear histogram on red"); break;
 126                         case HCHAN_G:   t1 = _("linear histogram on green"); break;
 127                         case HCHAN_B:   t1 = _("linear histogram on blue"); break;
 128                         case HCHAN_VAL: t1 = _("linear histogram on value"); break;
 129                         case HCHAN_RGB: t1 = _("linear histogram on RGB"); break;
 130                         case HCHAN_MAX: t1 = _("linear histogram on max value"); break;
 131                         }
 132         return t1;
 133 }
 134
 135 static HistMap *histmap_read(GdkPixbuf *imgpixbuf)
 136 {
 137         gint w, h, i, j, srs, has_alpha, step;
 138         guchar *s_pix;
 139
 140         HistMap *histmap;
 141
 142         w = gdk_pixbuf_get_width(imgpixbuf);
 143         h = gdk_pixbuf_get_height(imgpixbuf);
 144         srs = gdk_pixbuf_get_rowstride(imgpixbuf);
 145         s_pix = gdk_pixbuf_get_pixels(imgpixbuf);
 146         has_alpha = gdk_pixbuf_get_has_alpha(imgpixbuf);
 147
 148         histmap = g_new0(HistMap, 1);
 149
 150         step = 3 + !!(has_alpha);
 151         for (i = 0; i < h; i++)
 152                 {
 153                 guchar *sp = s_pix + (i * srs); /* 8bit */
 154                 for (j = 0; j < w; j++)
 155                         {
 156                         guint avg = (sp[0] + sp[1] + sp[2]) / 3;
 157                         guint max = sp[0];
 158                         if (sp[1] > max) max = sp[1];
 159                         if (sp[2] > max) max = sp[2];
 160
 161                         histmap->histmap[sp[0] * HISTMAP_CHANNELS + HISTMAP_CHANNEL_R]++;
 162                         histmap->histmap[sp[1] * HISTMAP_CHANNELS + HISTMAP_CHANNEL_G]++;
 163                         histmap->histmap[sp[2] * HISTMAP_CHANNELS + HISTMAP_CHANNEL_B]++;
 164                         histmap->histmap[avg   * HISTMAP_CHANNELS + HISTMAP_CHANNEL_AVG]++;
 165                         histmap->histmap[max   * HISTMAP_CHANNELS + HISTMAP_CHANNEL_MAX]++;
 166                         sp += step;
 167                         }
 168                 }
 169         histmap->area = w * h;
 170         return histmap;
 171 }
 172
 173 const HistMap *histmap_get(FileData *fd)
 174 {
 175         if (fd->histmap) return fd->histmap;
 176
 177         if (fd->pixbuf)
 178                 {
 179                 fd->histmap = histmap_read(fd->pixbuf);
 180                 return fd->histmap;
 181                 }
 182         return NULL;
 183 }
 184
 185 static void histogram_vgrid(Histogram *histogram, GdkPixbuf *pixbuf, gint x, gint y, gint width, gint height)
 186 {
 187         guint i;
 188         float add;
 189
 190         if (histogram->vgrid == 0) return;
 191
 192         add = width / (float)histogram->vgrid;
 193
 194         for (i = 1; i < histogram->vgrid; i++)
 195                 {
 196                 gint xpos = x + (int)(i * add + 0.5);
 197
 198                 pixbuf_draw_line(pixbuf, x, y, width, height, xpos, y, xpos, y + height,
 199                                  histogram->grid_color.R,
 200                                  histogram->grid_color.G,
 201                                  histogram->grid_color.B,
 202                                  histogram->grid_color.A);
 203                 }
 204 }
 205
 206 static void histogram_hgrid(Histogram *histogram, GdkPixbuf *pixbuf, gint x, gint y, gint width, gint height)
 207 {
 208         guint i;
 209         float add;
 210
 211         if (histogram->hgrid == 0) return;
 212
 213         add = height / (float)histogram->hgrid;
 214
 215         for (i = 1; i < histogram->hgrid; i++)
 216                 {
 217                 gint ypos = y + (int)(i * add + 0.5);
 218
 219                 pixbuf_draw_line(pixbuf, x, y, width, height, x, ypos, x + width, ypos,
 220                                  histogram->grid_color.R,
 221                                  histogram->grid_color.G,
 222                                  histogram->grid_color.B,
 223                                  histogram->grid_color.A);
 224                 }
 225 }
 226
 227 gint histogram_draw(Histogram *histogram, const HistMap *histmap, GdkPixbuf *pixbuf, gint x, gint y, gint width, gint height)
 228 {
 229         /* FIXME: use the coordinates correctly */
 230         gint i;
 231         gulong max = 0;
 232         gdouble logmax;
 233
 234         if (!histogram || !histmap) return 0;
 235
 236         /* Draw the grid */
 237         histogram_vgrid(histogram, pixbuf, x, y, width, height);
 238         histogram_hgrid(histogram, pixbuf, x, y, width, height);
 239
 240         for (i = 0; i < 1024; i++) {
 241 #if 0
 242                 /* this is probably broken for MAX or VAL mode */
 243                 gint flag = 0;
 244
 245                 switch (histogram->channel_mode)
 246                         {
 247                         case HCHAN_RGB: if ((i % HISTMAP_CHANNELS) < 3) flag = 1; break;
 248                         case HCHAN_R:   if ((i % HISTMAP_CHANNELS) == HISTMAP_CHANNEL_R) flag = 1; break;
 249                         case HCHAN_G:   if ((i % HISTMAP_CHANNELS) == HISTMAP_CHANNEL_G) flag = 1; break;
 250                         case HCHAN_B:   if ((i % HISTMAP_CHANNELS) == HISTMAP_CHANNEL_B) flag = 1; break;
 251                         case HCHAN_VAL: if ((i % HISTMAP_CHANNELS) == HISTMAP_CHANNEL_AVG) flag = 1; break;
 252                         case HCHAN_MAX: if ((i % HISTMAP_CHANNELS) == HISTMAP_CHANNEL_MAX) flag = 1; break;
 253                         }
 254                 if (flag && histmap->histmap[i] > max) max = histmap->histmap[i];
 255 #else
 256                 if (histmap->histmap[i] > max) max = histmap->histmap[i];
 257 #endif
 258         }
 259
 260         logmax = log(max);
 261         for (i = 0; i < width; i++)
 262                 {
 263                 gint j;
 264                 glong v[4] = {0, 0, 0, 0};
 265                 gint rplus = 0;
 266                 gint gplus = 0;
 267                 gint bplus = 0;
 268                 gint ii = i * HISTMAP_SIZE / width;
 269                 gint combine  = (HISTMAP_SIZE - 1) / width + 1;
 270
 271                 for (j = 0; j < combine; j++)
 272                         {
 273                         v[0] += histmap->histmap[(ii + j) * HISTMAP_CHANNELS + HISTMAP_CHANNEL_R]; // r
 274                         v[1] += histmap->histmap[(ii + j) * HISTMAP_CHANNELS + HISTMAP_CHANNEL_G]; // g
 275                         v[2] += histmap->histmap[(ii + j) * HISTMAP_CHANNELS + HISTMAP_CHANNEL_B]; // b
 276                         v[3] += histmap->histmap[(ii + j) * HISTMAP_CHANNELS +
 277                                 ((histogram->channel_mode == HCHAN_VAL) ? HISTMAP_CHANNEL_AVG : HISTMAP_CHANNEL_MAX)]; // value, max
 278                         }
 279
 280                 for (j = 0; j < 4; j++)
 281                         {
 282                         v[j] /= combine;
 283                         }
 284
 285                 for (j = 0; j < 4; j++)
 286                         {
 287                         gint max2 = 0;
 288                         gint k;
 289
 290                         for (k = 1; k < 4; k++)
 291                                 if (v[k] > v[max2]) max2 = k;
 292
 293                         if (histogram->channel_mode >= HCHAN_RGB
 294                             || max2 == histogram->channel_mode)
 295                                 {
 296                                 gulong pt;
 297                                 gint r = rplus;
 298                                 gint g = gplus;
 299                                 gint b = bplus;
 300
 301                                 switch (max2)
 302                                         {
 303                                         case HCHAN_R: rplus = r = 255; break;
 304                                         case HCHAN_G: gplus = g = 255; break;
 305                                         case HCHAN_B: bplus = b = 255; break;
 306                                         }
 307
 308                                 switch (histogram->channel_mode)
 309                                         {
 310                                         case HCHAN_RGB:
 311                                                 if (r == 255 && g == 255 && b == 255)
 312                                                         {
 313                                                         r = 0; b = 0; g = 0;
 314                                                         }
 315                                                 break;
 316                                         case HCHAN_R:          b = 0; g = 0; break;
 317                                         case HCHAN_G:   r = 0; b = 0;        break;
 318                                         case HCHAN_B:   r = 0;        g = 0; break;
 319                                         case HCHAN_MAX:
 320                                         case HCHAN_VAL: r = 0; b = 0; g = 0; break;
 321                                         }
 322
 323                                 if (v[max2] == 0)
 324                                         pt = 0;
 325                                 else if (histogram->log_mode)
 326                                         pt = ((float)log(v[max2])) / logmax * (height - 1);
 327                                 else
 328                                         pt = ((float)v[max2])/ max * (height - 1);
 329
 330                                 pixbuf_draw_line(pixbuf,
 331                                         x, y, width, height,
 332                                         x + i, y + height, x + i, y + height - pt,
 333                                         r, g, b, 255);
 334                                 }
 335                         v[max2] = -1;
 336                         }
 337                 }
 338
 339         return TRUE;
 340 }
 341
 342 void histogram_notify_cb(FileData *fd, NotifyType type, gpointer data)
 343 {
 344         if (type != NOTIFY_TYPE_INTERNAL && fd->histmap)
 345                 {
 346                 g_free(fd->histmap);
 347                 fd->histmap = NULL;
 348                 }
 349 }
 350
 351 /* vim: set shiftwidth=8 softtabstop=0 cindent cinoptions={1s: */