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