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
  28 struct _HistMap {
  29         gulong r[HISTMAP_SIZE];
  30         gulong g[HISTMAP_SIZE];
  31         gulong b[HISTMAP_SIZE];
  32         gulong max[HISTMAP_SIZE];
  33 };
  34
  35 struct _Histogram {
  36         gint channel_mode; /* drawing mode for histogram */
  37         gint log_mode;     /* logarithmical or not */
  38         guint vgrid; /* number of vertical divisions, 0 for none */
  39         guint hgrid; /* number of horizontal divisions, 0 for none */
  40         struct {
  41                 int R; /* red */
  42                 int G; /* green */
  43                 int B; /* blue */
  44                 int A; /* alpha */
  45         } grid_color;  /* grid color */
  46
  47 };
  48
  49 Histogram *histogram_new(void)
  50 {
  51         Histogram *histogram;
  52
  53         histogram = g_new0(Histogram, 1);
  54         histogram->channel_mode = options->histogram.last_channel_mode;
  55         histogram->log_mode = options->histogram.last_log_mode;
  56
  57         /* grid */
  58         histogram->vgrid = 5;
  59         histogram->hgrid = 3;
  60         histogram->grid_color.R = 160;
  61         histogram->grid_color.G = 160;
  62         histogram->grid_color.B = 160;
  63         histogram->grid_color.A = 250;
  64
  65         return histogram;
  66 }
  67
  68 void histogram_free(Histogram *histogram)
  69 {
  70         g_free(histogram);
  71 }
  72
  73
  74 gint histogram_set_channel(Histogram *histogram, gint chan)
  75 {
  76         if (!histogram) return 0;
  77         options->histogram.last_channel_mode = histogram->channel_mode = chan;
  78         return chan;
  79 }
  80
  81 gint histogram_get_channel(Histogram *histogram)
  82 {
  83         if (!histogram) return 0;
  84         return histogram->channel_mode;
  85 }
  86
  87 gint histogram_set_mode(Histogram *histogram, gint mode)
  88 {
  89         if (!histogram) return 0;
  90         options->histogram.last_log_mode = histogram->log_mode = mode;
  91         return mode;
  92 }
  93
  94 gint histogram_get_mode(Histogram *histogram)
  95 {
  96         if (!histogram) return 0;
  97         return histogram->log_mode;
  98 }
  99
 100 const gchar *histogram_label(Histogram *histogram)
 101 {
 102         const gchar *t1 = "";
 103
 104         if (!histogram) return NULL;
 105
 106         if (histogram->log_mode)
 107                 switch (histogram->channel_mode)
 108                         {
 109                         case HCHAN_R:   t1 = _("logarithmical histogram on red"); break;
 110                         case HCHAN_G:   t1 = _("logarithmical histogram on green"); break;
 111                         case HCHAN_B:   t1 = _("logarithmical histogram on blue"); break;
 112                         case HCHAN_RGB: t1 = _("logarithmical histogram on RGB"); break;
 113                         case HCHAN_MAX: t1 = _("logarithmical histogram on max value"); break;
 114                         }
 115         else
 116                 switch (histogram->channel_mode)
 117                         {
 118                         case HCHAN_R:   t1 = _("linear histogram on red"); break;
 119                         case HCHAN_G:   t1 = _("linear histogram on green"); break;
 120                         case HCHAN_B:   t1 = _("linear histogram on blue"); break;
 121                         case HCHAN_RGB: t1 = _("linear histogram on RGB"); break;
 122                         case HCHAN_MAX: t1 = _("linear histogram on max value"); break;
 123                         }
 124         return t1;
 125 }
 126
 127 static HistMap *histmap_read(GdkPixbuf *imgpixbuf)
 128 {
 129         gint w, h, i, j, srs, has_alpha, step;
 130         guchar *s_pix;
 131         HistMap *histmap;
 132
 133         w = gdk_pixbuf_get_width(imgpixbuf);
 134         h = gdk_pixbuf_get_height(imgpixbuf);
 135         srs = gdk_pixbuf_get_rowstride(imgpixbuf);
 136         s_pix = gdk_pixbuf_get_pixels(imgpixbuf);
 137         has_alpha = gdk_pixbuf_get_has_alpha(imgpixbuf);
 138
 139         histmap = g_new0(HistMap, 1);
 140
 141         step = 3 + !!(has_alpha);
 142         for (i = 0; i < h; i++)
 143                 {
 144                 guchar *sp = s_pix + (i * srs); /* 8bit */
 145                 for (j = 0; j < w; j++)
 146                         {
 147                         guint max = sp[0];
 148                         if (sp[1] > max) max = sp[1];
 149                         if (sp[2] > max) max = sp[2];
 150
 151                         histmap->r[sp[0]]++;
 152                         histmap->g[sp[1]]++;
 153                         histmap->b[sp[2]]++;
 154                         histmap->max[max]++;
 155
 156                         sp += step;
 157                         }
 158                 }
 159
 160         return histmap;
 161 }
 162
 163 const HistMap *histmap_get(FileData *fd)
 164 {
 165         if (fd->histmap) return fd->histmap;
 166
 167         if (fd->pixbuf)
 168                 {
 169                 fd->histmap = histmap_read(fd->pixbuf);
 170                 return fd->histmap;
 171                 }
 172         return NULL;
 173 }
 174
 175 static void histogram_vgrid(Histogram *histogram, GdkPixbuf *pixbuf, gint x, gint y, gint width, gint height)
 176 {
 177         guint i;
 178         float add;
 179
 180         if (histogram->vgrid == 0) return;
 181
 182         add = width / (float)histogram->vgrid;
 183
 184         for (i = 1; i < histogram->vgrid; i++)
 185                 {
 186                 gint xpos = x + (int)(i * add + 0.5);
 187
 188                 pixbuf_draw_line(pixbuf, x, y, width, height, xpos, y, xpos, y + height,
 189                                  histogram->grid_color.R,
 190                                  histogram->grid_color.G,
 191                                  histogram->grid_color.B,
 192                                  histogram->grid_color.A);
 193                 }
 194 }
 195
 196 static void histogram_hgrid(Histogram *histogram, GdkPixbuf *pixbuf, gint x, gint y, gint width, gint height)
 197 {
 198         guint i;
 199         float add;
 200
 201         if (histogram->hgrid == 0) return;
 202
 203         add = height / (float)histogram->hgrid;
 204
 205         for (i = 1; i < histogram->hgrid; i++)
 206                 {
 207                 gint ypos = y + (int)(i * add + 0.5);
 208
 209                 pixbuf_draw_line(pixbuf, x, y, width, height, x, ypos, x + width, ypos,
 210                                  histogram->grid_color.R,
 211                                  histogram->grid_color.G,
 212                                  histogram->grid_color.B,
 213                                  histogram->grid_color.A);
 214                 }
 215 }
 216
 217 gint histogram_draw(Histogram *histogram, const HistMap *histmap, GdkPixbuf *pixbuf, gint x, gint y, gint width, gint height)
 218 {
 219         /* FIXME: use the coordinates correctly */
 220         gint i;
 221         gulong max = 0;
 222         gdouble logmax;
 223         gint combine = (HISTMAP_SIZE - 1) / width + 1;
 224         gint ypos = y + height;
 225
 226         if (!histogram || !histmap) return 0;
 227
 228         /* Draw the grid */
 229         histogram_vgrid(histogram, pixbuf, x, y, width, height);
 230         histogram_hgrid(histogram, pixbuf, x, y, width, height);
 231
 232         for (i = 0; i < HISTMAP_SIZE; i++)
 233                 {
 234                 if (histmap->r[i] > max) max = histmap->r[i];
 235                 if (histmap->g[i] > max) max = histmap->g[i];
 236                 if (histmap->b[i] > max) max = histmap->b[i];
 237                 }
 238
 239         if (max > 0)
 240                 logmax = log(max);
 241         else
 242                 logmax = 1.0;
 243
 244         for (i = 0; i < width; i++)
 245                 {
 246                 gint j;
 247                 glong v[4] = {0, 0, 0, 0};
 248                 gint rplus = 0;
 249                 gint gplus = 0;
 250                 gint bplus = 0;
 251                 gint ii = i * HISTMAP_SIZE / width;
 252                 gint xpos = x + i;
 253
 254                 for (j = 0; j < combine; j++)
 255                         {
 256                         guint p = ii + j;
 257                         v[0] += histmap->r[p];
 258                         v[1] += histmap->g[p];
 259                         v[2] += histmap->b[p];
 260                         v[3] += histmap->max[p];
 261                         }
 262
 263                 for (j = 0; combine > 1 && j < 4; j++)
 264                         v[j] /= combine;
 265
 266                 for (j = 0; j < 4; j++)
 267                         {
 268                         gint k;
 269                         gint chanmax = 0;
 270
 271                         for (k = 1; k < 3; k++)
 272                                 if (v[k] > v[chanmax])
 273                                         chanmax = k;
 274
 275                         if (histogram->channel_mode >= HCHAN_RGB
 276                             || chanmax == histogram->channel_mode)
 277                                 {
 278                                 gulong pt;
 279                                 gint r = rplus;
 280                                 gint g = gplus;
 281                                 gint b = bplus;
 282
 283                                 switch (chanmax)
 284                                         {
 285                                         case 0: rplus = r = 255; break;
 286                                         case 1: gplus = g = 255; break;
 287                                         case 2: bplus = b = 255; break;
 288                                         }
 289
 290                                 switch (histogram->channel_mode)
 291                                         {
 292                                         case HCHAN_RGB:
 293                                                 if (r == 255 && g == 255 && b == 255)
 294                                                         {
 295                                                         r = 0; b = 0; g = 0;
 296                                                         }
 297                                                 break;
 298                                         case HCHAN_R:     b = 0; g = 0; break;
 299                                         case HCHAN_G:   r = 0; b = 0;   break;
 300                                         case HCHAN_B:   r = 0;  g = 0; break;
 301                                         case HCHAN_MAX: r = 0; b = 0; g = 0; break;
 302                                         }
 303
 304                                 if (v[chanmax] == 0)
 305                                         pt = 0;
 306                                 else if (histogram->log_mode)
 307                                         pt = ((gdouble)log(v[chanmax])) / logmax * (height - 1);
 308                                 else
 309                                         pt = ((gdouble)v[chanmax]) / max * (height - 1);
 310
 311                                 pixbuf_draw_line(pixbuf,
 312                                         x, y, width, height,
 313                                         xpos, ypos, xpos, ypos - pt,
 314                                         r, g, b, 255);
 315                                 }
 316
 317                         v[chanmax] = -1;
 318                         }
 319                 }
 320
 321         return TRUE;
 322 }
 323
 324 void histogram_notify_cb(FileData *fd, NotifyType type, gpointer data)
 325 {
 326         if (type != NOTIFY_TYPE_INTERNAL && fd->histmap)
 327                 {
 328                 g_free(fd->histmap);
 329                 fd->histmap = NULL;
 330                 }
 331 }
 332
 333 /* vim: set shiftwidth=8 softtabstop=0 cindent cinoptions={1s: */