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 histogram_chan;
  43         gint histogram_logmode;
  44 };
  45
  46
  47 Histogram *histogram_new(void)
  48 {
  49         Histogram *histogram;
  50
  51         histogram = g_new0(Histogram, 1);
  52         histogram->histogram_chan = options->histogram.last_channel_mode;
  53         histogram->histogram_logmode = options->histogram.last_log_mode;
  54
  55         return histogram;
  56 }
  57
  58 void histogram_free(Histogram *histogram)
  59 {
  60         g_free(histogram);
  61 }
  62
  63
  64 gint histogram_set_channel(Histogram *histogram, gint chan)
  65 {
  66         if (!histogram) return 0;
  67         options->histogram.last_channel_mode = histogram->histogram_chan = chan;
  68         return chan;
  69 }
  70
  71 gint histogram_get_channel(Histogram *histogram)
  72 {
  73         if (!histogram) return 0;
  74         return histogram->histogram_chan;
  75 }
  76
  77 gint histogram_set_mode(Histogram *histogram, gint mode)
  78 {
  79         if (!histogram) return 0;
  80         options->histogram.last_log_mode = histogram->histogram_logmode = mode;
  81         return mode;
  82 }
  83
  84 gint histogram_get_mode(Histogram *histogram)
  85 {
  86         if (!histogram) return 0;
  87         return histogram->histogram_logmode;
  88 }
  89
  90 const gchar *histogram_label(Histogram *histogram)
  91 {
  92         const gchar *t1 = "";
  93
  94         if (!histogram) return NULL;
  95
  96         if (histogram->histogram_logmode)
  97                 switch (histogram->histogram_chan)
  98                         {
  99                         case HCHAN_R:   t1 = _("logarithmical histogram on red"); break;
 100                         case HCHAN_G:   t1 = _("logarithmical histogram on green"); break;
 101                         case HCHAN_B:   t1 = _("logarithmical histogram on blue"); break;
 102                         case HCHAN_VAL: t1 = _("logarithmical histogram on value"); break;
 103                         case HCHAN_RGB: t1 = _("logarithmical histogram on RGB"); break;
 104                         case HCHAN_MAX: t1 = _("logarithmical histogram on max value"); break;
 105                         }
 106         else
 107                 switch (histogram->histogram_chan)
 108                         {
 109                         case HCHAN_R:   t1 = _("linear histogram on red"); break;
 110                         case HCHAN_G:   t1 = _("linear histogram on green"); break;
 111                         case HCHAN_B:   t1 = _("linear histogram on blue"); break;
 112                         case HCHAN_VAL: t1 = _("linear histogram on value"); break;
 113                         case HCHAN_RGB: t1 = _("linear histogram on RGB"); break;
 114                         case HCHAN_MAX: t1 = _("linear histogram on max value"); break;
 115                         }
 116         return t1;
 117 }
 118
 119 static HistMap *histmap_read(GdkPixbuf *imgpixbuf)
 120 {
 121         gint w, h, i, j, srs, has_alpha, step;
 122         guchar *s_pix;
 123
 124         HistMap *histmap;
 125
 126         w = gdk_pixbuf_get_width(imgpixbuf);
 127         h = gdk_pixbuf_get_height(imgpixbuf);
 128         srs = gdk_pixbuf_get_rowstride(imgpixbuf);
 129         s_pix = gdk_pixbuf_get_pixels(imgpixbuf);
 130         has_alpha = gdk_pixbuf_get_has_alpha(imgpixbuf);
 131
 132         histmap = g_new0(HistMap, 1);
 133
 134         step = 3 + !!(has_alpha);
 135         for (i = 0; i < h; i++)
 136                 {
 137                 guchar *sp = s_pix + (i * srs); /* 8bit */
 138                 for (j = 0; j < w; j++)
 139                         {
 140                         guint avg = (sp[0] + sp[1] + sp[2]) / 3;
 141                         guint max = sp[0];
 142                         if (sp[1] > max) max = sp[1];
 143                         if (sp[2] > max) max = sp[2];
 144
 145                         histmap->histmap[sp[0] * HISTMAP_CHANNELS + HISTMAP_CHANNEL_R]++;
 146                         histmap->histmap[sp[1] * HISTMAP_CHANNELS + HISTMAP_CHANNEL_G]++;
 147                         histmap->histmap[sp[2] * HISTMAP_CHANNELS + HISTMAP_CHANNEL_B]++;
 148                         histmap->histmap[avg   * HISTMAP_CHANNELS + HISTMAP_CHANNEL_AVG]++;
 149                         histmap->histmap[max   * HISTMAP_CHANNELS + HISTMAP_CHANNEL_MAX]++;
 150                         sp += step;
 151                         }
 152                 }
 153         histmap->area = w * h;
 154         return histmap;
 155 }
 156
 157 const HistMap *histmap_get(FileData *fd)
 158 {
 159         if (fd->histmap) return fd->histmap;
 160
 161         if (fd->pixbuf)
 162                 {
 163                 fd->histmap = histmap_read(fd->pixbuf);
 164                 return fd->histmap;
 165                 }
 166         return NULL;
 167 }
 168
 169 gint histogram_draw(Histogram *histogram, const HistMap *histmap, GdkPixbuf *pixbuf, gint x, gint y, gint width, gint height)
 170 {
 171         /* FIXME: use the coordinates correctly */
 172         gint i;
 173         gulong max = 0;
 174         gdouble logmax;
 175
 176         if (!histogram || !histmap) return 0;
 177
 178         for (i = 0; i < 1024; i++) {
 179 #if 0
 180                 /* this is probably broken for MAX or VAL mode */
 181                 gint flag = 0;
 182
 183                 switch (histogram->histogram_chan)
 184                         {
 185                         case HCHAN_RGB: if ((i % HISTMAP_CHANNELS) < 3) flag = 1; break;
 186                         case HCHAN_R:   if ((i % HISTMAP_CHANNELS) == HISTMAP_CHANNEL_R) flag = 1; break;
 187                         case HCHAN_G:   if ((i % HISTMAP_CHANNELS) == HISTMAP_CHANNEL_G) flag = 1; break;
 188                         case HCHAN_B:   if ((i % HISTMAP_CHANNELS) == HISTMAP_CHANNEL_B) flag = 1; break;
 189                         case HCHAN_VAL: if ((i % HISTMAP_CHANNELS) == HISTMAP_CHANNEL_AVG) flag = 1; break;
 190                         case HCHAN_MAX: if ((i % HISTMAP_CHANNELS) == HISTMAP_CHANNEL_MAX) flag = 1; break;
 191                         }
 192                 if (flag && histmap->histmap[i] > max) max = histmap->histmap[i];
 193 #else
 194                 if (histmap->histmap[i] > max) max = histmap->histmap[i];
 195 #endif
 196         }
 197
 198         logmax = log(max);
 199         for (i = 0; i < width; i++)
 200                 {
 201                 gint j;
 202                 glong v[4] = {0, 0, 0, 0};
 203                 gint rplus = 0;
 204                 gint gplus = 0;
 205                 gint bplus = 0;
 206                 gint ii = i * HISTMAP_SIZE / width;
 207                 gint combine  = (HISTMAP_SIZE - 1) / width + 1;
 208
 209                 for (j = 0; j < combine; j++)
 210                         {
 211                         v[0] += histmap->histmap[(ii + j) * HISTMAP_CHANNELS + HISTMAP_CHANNEL_R]; // r
 212                         v[1] += histmap->histmap[(ii + j) * HISTMAP_CHANNELS + HISTMAP_CHANNEL_G]; // g
 213                         v[2] += histmap->histmap[(ii + j) * HISTMAP_CHANNELS + HISTMAP_CHANNEL_B]; // b
 214                         v[3] += histmap->histmap[(ii + j) * HISTMAP_CHANNELS +
 215                                 ((histogram->histogram_chan == HCHAN_VAL) ? HISTMAP_CHANNEL_AVG : HISTMAP_CHANNEL_MAX)]; // value, max
 216                         }
 217
 218                 for (j = 0; j < 4; j++)
 219                         {
 220                         v[j] /= combine;
 221                         }
 222
 223                 for (j = 0; j < 4; j++)
 224                         {
 225                         gint max2 = 0;
 226                         gint k;
 227
 228                         for (k = 1; k < 4; k++)
 229                                 if (v[k] > v[max2]) max2 = k;
 230
 231                         if (histogram->histogram_chan >= HCHAN_RGB
 232                             || max2 == histogram->histogram_chan)
 233                                 {
 234                                 gulong pt;
 235                                 gint r = rplus;
 236                                 gint g = gplus;
 237                                 gint b = bplus;
 238
 239                                 switch (max2)
 240                                         {
 241                                         case HCHAN_R: rplus = r = 255; break;
 242                                         case HCHAN_G: gplus = g = 255; break;
 243                                         case HCHAN_B: bplus = b = 255; break;
 244                                         }
 245
 246                                 switch (histogram->histogram_chan)
 247                                         {
 248                                         case HCHAN_RGB:
 249                                                 if (r == 255 && g == 255 && b == 255)
 250                                                         {
 251                                                         r = 0; b = 0; g = 0;
 252                                                         }
 253                                                 break;
 254                                         case HCHAN_R:          b = 0; g = 0; break;
 255                                         case HCHAN_G:   r = 0; b = 0;        break;
 256                                         case HCHAN_B:   r = 0;        g = 0; break;
 257                                         case HCHAN_MAX:
 258                                         case HCHAN_VAL: r = 0; b = 0; g = 0; break;
 259                                         }
 260
 261                                 if (v[max2] == 0)
 262                                         pt = 0;
 263                                 else if (histogram->histogram_logmode)
 264                                         pt = ((float)log(v[max2])) / logmax * (height - 1);
 265                                 else
 266                                         pt = ((float)v[max2])/ max * (height - 1);
 267
 268                                 pixbuf_draw_line(pixbuf,
 269                                         x, y, width, height,
 270                                         x + i, y + height, x + i, y + height - pt,
 271                                         r, g, b, 255);
 272                                 }
 273                         v[max2] = -1;
 274                         }
 275                 }
 276
 277         return TRUE;
 278 }
 279
 280 void histogram_notify_cb(FileData *fd, NotifyType type, gpointer data)
 281 {
 282         if (type != NOTIFY_TYPE_INTERNAL && fd->histmap)
 283                 {
 284                 g_free(fd->histmap);
 285                 fd->histmap = NULL;
 286                 }
 287 }
 288
 289 /* vim: set shiftwidth=8 softtabstop=0 cindent cinoptions={1s: */