mirror of https://github.com/GNOME/gimp.git
83 lines
2.1 KiB
C
83 lines
2.1 KiB
C
/* GIMP - The GNU Image Manipulation Program
|
|
* Copyright (C) 1995 Spencer Kimball and Peter Mattis
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation; either version 2 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to the Free Software
|
|
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
|
|
*/
|
|
|
|
#include "config.h"
|
|
|
|
#include <glib-object.h>
|
|
|
|
#include "base-types.h"
|
|
|
|
#include "pixel-region.h"
|
|
#include "threshold.h"
|
|
|
|
|
|
void
|
|
threshold (Threshold *tr,
|
|
PixelRegion *srcPR,
|
|
PixelRegion *destPR)
|
|
{
|
|
const guchar *src, *s;
|
|
guchar *dest, *d;
|
|
gboolean has_alpha;
|
|
gint alpha;
|
|
gint w, h, b;
|
|
gint value;
|
|
|
|
h = srcPR->h;
|
|
src = srcPR->data;
|
|
dest = destPR->data;
|
|
has_alpha = (srcPR->bytes == 2 || srcPR->bytes == 4);
|
|
alpha = has_alpha ? srcPR->bytes - 1 : srcPR->bytes;
|
|
|
|
while (h--)
|
|
{
|
|
w = srcPR->w;
|
|
s = src;
|
|
d = dest;
|
|
|
|
while (w--)
|
|
{
|
|
if (tr->color)
|
|
{
|
|
value = MAX (s[RED_PIX], s[GREEN_PIX]);
|
|
value = MAX (value, s[BLUE_PIX]);
|
|
|
|
value = (value >= tr->low_threshold &&
|
|
value <= tr->high_threshold ) ? 255 : 0;
|
|
}
|
|
else
|
|
{
|
|
value = (s[GRAY_PIX] >= tr->low_threshold &&
|
|
s[GRAY_PIX] <= tr->high_threshold) ? 255 : 0;
|
|
}
|
|
|
|
for (b = 0; b < alpha; b++)
|
|
d[b] = value;
|
|
|
|
if (has_alpha)
|
|
d[alpha] = s[alpha];
|
|
|
|
s += srcPR->bytes;
|
|
d += destPR->bytes;
|
|
}
|
|
|
|
src += srcPR->rowstride;
|
|
dest += destPR->rowstride;
|
|
}
|
|
}
|