static void
gimp_histogram_editor_info_update (GimpHistogramEditor *editor)
{
GimpHistogramView *view = GIMP_HISTOGRAM_BOX (editor->box)->view;
GimpHistogram *hist = editor->histogram;
if (hist)
{
gint n_bins;
gdouble pixels;
gdouble count;
gchar text[12];
n_bins = gimp_histogram_n_bins (hist);
pixels = gimp_histogram_get_count (hist, view->channel, 0, n_bins - 1);
count = gimp_histogram_get_count (hist, view->channel,
view->start, view->end);
g_snprintf (text, sizeof (text), "%.3f",
gimp_histogram_get_mean (hist, view->channel,
view->start, view->end));
gtk_label_set_text (GTK_LABEL (editor->labels[0]), text);
g_snprintf (text, sizeof (text), "%.3f",
gimp_histogram_get_std_dev (hist, view->channel,
view->start, view->end));
gtk_label_set_text (GTK_LABEL (editor->labels[1]), text);
g_snprintf (text, sizeof (text), "%.3f",
gimp_histogram_get_median (hist, view->channel,
view->start,
view->end));
gtk_label_set_text (GTK_LABEL (editor->labels[2]), text);
g_snprintf (text, sizeof (text), "%d", (gint) pixels);
gtk_label_set_text (GTK_LABEL (editor->labels[3]), text);
g_snprintf (text, sizeof (text), "%d", (gint) count);
gtk_label_set_text (GTK_LABEL (editor->labels[4]), text);
g_snprintf (text, sizeof (text), "%.1f", (pixels > 0 ?
(100.0 * count / pixels) :
0.0));
gtk_label_set_text (GTK_LABEL (editor->labels[5]), text);
}
else
{
gint i;
for (i = 0; i < 6; i++)
gtk_label_set_text (GTK_LABEL (editor->labels[i]), NULL);
}
}
gdouble
gimp_histogram_get_std_dev (GimpHistogram *histogram,
GimpHistogramChannel channel,
gint start,
gint end)
{
gint i;
gdouble dev = 0.0;
gdouble count;
gdouble mean;
g_return_val_if_fail (histogram != NULL, 0.0);
/* the gray alpha channel is in slot 1 */
if (histogram->n_channels == 3 && channel == GIMP_HISTOGRAM_ALPHA)
channel = 1;
if (! histogram->values ||
start > end ||
(channel == GIMP_HISTOGRAM_RGB && histogram->n_channels < 4) ||
(channel != GIMP_HISTOGRAM_RGB && channel >= histogram->n_channels))
return 0.0;
mean = gimp_histogram_get_mean (histogram, channel, start, end);
count = gimp_histogram_get_count (histogram, channel, start, end);
if (count == 0.0)
count = 1.0;
for (i = start; i <= end; i++)
{
gdouble value;
if (channel == GIMP_HISTOGRAM_RGB)
{
value = (HISTOGRAM_VALUE (GIMP_HISTOGRAM_RED, i) +
HISTOGRAM_VALUE (GIMP_HISTOGRAM_GREEN, i) +
HISTOGRAM_VALUE (GIMP_HISTOGRAM_BLUE, i));
}
else
{
value = gimp_histogram_get_value (histogram, channel, i);
}
dev += value * SQR (i - mean);
}
return sqrt (dev / count);
}
