1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
|
/* 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 3 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, see <http://www.gnu.org/licenses/>.
*/
#include "config.h"
#include <gegl.h>
#include "core-types.h"
#include "gimpimage.h"
#include "gimpimage-colorhash.h"
#include "gimpimage-colormap.h"
#define MAXDIFF 195076
#define HASH_TABLE_SIZE 1021
typedef struct _ColorHash ColorHash;
struct _ColorHash
{
gint pixel; /* R << 16 | G << 8 | B */
gint index; /* colormap index */
GimpImage *image;
};
static ColorHash color_hash_table[HASH_TABLE_SIZE];
static gint color_hash_misses;
static gint color_hash_hits;
void
gimp_image_color_hash_init (void)
{
gint i;
/* initialize the color hash table--invalidate all entries */
for (i = 0; i < HASH_TABLE_SIZE; i++)
{
color_hash_table[i].pixel = 0;
color_hash_table[i].index = 0;
color_hash_table[i].image = NULL;
}
color_hash_misses = 0;
color_hash_hits = 0;
}
void
gimp_image_color_hash_exit (void)
{
#if 0
/* print out the hash table statistics */
g_print ("RGB->indexed hash table lookups: %d\n",
color_hash_hits + color_hash_misses);
g_print ("RGB->indexed hash table hits: %d\n", color_hash_hits);
g_print ("RGB->indexed hash table misses: %d\n", color_hash_misses);
g_print ("RGB->indexed hash table hit rate: %f\n",
100.0 * color_hash_hits / (color_hash_hits + color_hash_misses));
#endif
}
void
gimp_image_color_hash_invalidate (GimpImage *image,
gint index)
{
gint i;
g_return_if_fail (GIMP_IS_IMAGE (image));
if (index == -1) /* invalidate all entries */
{
for (i = 0; i < HASH_TABLE_SIZE; i++)
if (color_hash_table[i].image == image)
{
color_hash_table[i].pixel = 0;
color_hash_table[i].index = 0;
color_hash_table[i].image = NULL;
}
}
else
{
for (i = 0; i < HASH_TABLE_SIZE; i++)
if (color_hash_table[i].image == image &&
color_hash_table[i].index == index)
{
color_hash_table[i].pixel = 0;
color_hash_table[i].index = 0;
color_hash_table[i].image = NULL;
}
}
}
gint
gimp_image_color_hash_rgb_to_indexed (const GimpImage *image,
gint r,
gint g,
gint b)
{
const guchar *cmap;
gint num_cols;
guint pixel;
gint hash_index;
gint cmap_index;
cmap = gimp_image_get_colormap (image);
num_cols = gimp_image_get_colormap_size (image);
pixel = (r << 16) | (g << 8) | b;
hash_index = pixel % HASH_TABLE_SIZE;
if (color_hash_table[hash_index].image == image &&
color_hash_table[hash_index].pixel == pixel)
{
/* Hash table lookup hit */
cmap_index = color_hash_table[hash_index].index;
color_hash_hits++;
}
else
{
/* Hash table lookup miss */
const guchar *col;
gint diff, sum, max;
gint i;
max = MAXDIFF;
cmap_index = 0;
col = cmap;
for (i = 0; i < num_cols; i++)
{
diff = r - *col++;
sum = diff * diff;
diff = g - *col++;
sum += diff * diff;
diff = b - *col++;
sum += diff * diff;
if (sum < max)
{
cmap_index = i;
max = sum;
}
}
/* update the hash table */
color_hash_table[hash_index].pixel = pixel;
color_hash_table[hash_index].index = cmap_index;
color_hash_table[hash_index].image = (GimpImage *) image;
color_hash_misses++;
}
return cmap_index;
}
|
