void threshold_image(
Glib::RefPtr<Gdk::Pixbuf>& img,
color low,
color high,
color replace_false,
color replace_true,
COLOR_SPACE space)
{
Gdk::Colorspace cspace = img->get_colorspace();
guint8 * pixels = img->get_pixels();
int bits_per_sample = img->get_bits_per_sample();
int n_channels = img->get_n_channels();
bool has_alpha = img->get_has_alpha();
int width = img->get_width();
int height = img->get_height();
int rowstride = img->get_rowstride();
assert(bits_per_sample == 8);
assert(cspace == Gdk::COLORSPACE_RGB);
//the above should be true for any image...
//right now 24/32 bit RGB/RGBA is the only supported color space
//todo: make this more pretty! wrapper?
guint8 * row = pixels;
for (int i = 0; i < height; i++) {
guint8 * p = row;
for (int j = 0; j < width; j++) {
if (is_in_range(p, low, high, space)) {
set_color(p, replace_true);
}
else {
set_color(p, replace_false);
}
p += n_channels; //should be n_channels * bits_per_sample/8
}
row += rowstride;
}
}
