gimp/app/gimpdrawable-equalize.c

91 lines
2.4 KiB
C

/* The GIMP -- an 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 <stdlib.h>
#include <string.h>
#include <math.h>
#include "drawable.h"
#include "equalize.h"
#include "gimage.h"
#include "gimplut.h"
#include "lut_funcs.h"
#include "gimphistogram.h"
#include "libgimp/gimpintl.h"
void
image_equalize (void *gimage_ptr)
{
GimpImage *gimage;
GimpDrawable *drawable;
gimage = (GimpImage *) gimage_ptr;
drawable = gimage_active_drawable (gimage);
if (gimp_drawable_indexed (drawable))
{
g_message (_("Equalize does not operate on indexed drawables."));
return;
}
equalize (gimage, drawable, TRUE);
}
void
equalize (GimpImage *gimage,
GimpDrawable *drawable,
gboolean mask_only)
{
PixelRegion srcPR, destPR;
unsigned char *mask;
int has_alpha;
int alpha, bytes;
int x1, y1, x2, y2;
GimpHistogram *hist;
GimpLut *lut;
mask = NULL;
bytes = drawable_bytes (drawable);
has_alpha = drawable_has_alpha (drawable);
alpha = has_alpha ? (bytes - 1) : bytes;
hist = gimp_histogram_new();
gimp_histogram_calculate_drawable(hist, drawable);
/* Build equalization LUT */
lut = eq_histogram_lut_new (hist, bytes);
/* Apply the histogram */
drawable_mask_bounds (drawable, &x1, &y1, &x2, &y2);
pixel_region_init (&srcPR, drawable_data (drawable), x1, y1, (x2 - x1), (y2 - y1), FALSE);
pixel_region_init (&destPR, drawable_shadow (drawable), x1, y1, (x2 - x1), (y2 - y1), TRUE);
pixel_regions_process_parallel((p_func)gimp_lut_process, lut,
2, &srcPR, &destPR);
gimp_lut_free(lut);
gimp_histogram_free(hist);
drawable_merge_shadow (drawable, TRUE);
drawable_update (drawable, x1, y1, (x2 - x1), (y2 - y1));
}