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
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
|
/*
* "$Id$"
*
* Dither test program for CUPS.
*
* Try the following:
*
* testdither 0 255 > filename.ppm
* testdither 0 127 255 > filename.ppm
* testdither 0 85 170 255 > filename.ppm
* testdither 0 63 127 170 198 227 255 > filename.ppm
* testdither 0 210 383 > filename.ppm
* testdither 0 82 255 > filename.ppm
*
* Copyright 2007-2011 by Apple Inc.
* Copyright 1993-2005 by Easy Software Products.
*
* These coded instructions, statements, and computer programs are the
* property of Apple Inc. and are protected by Federal copyright
* law. Distribution and use rights are outlined in the file "LICENSE.txt"
* which should have been included with this file. If this file is
* file is missing or damaged, see the license at "http://www.cups.org/".
*
* Contents:
*
* main() - Test dithering and output a PPM file.
* usage() - Show program usage...
*/
/*
* Include necessary headers.
*/
#include "driver.h"
#include <config.h>
#include <string.h>
#include <ctype.h>
/*
* Local functions...
*/
void usage(void);
/*
* 'main()' - Test dithering and output a PPM file.
*/
int /* O - Exit status */
main(int argc, /* I - Number of command-line arguments */
char *argv[]) /* I - Command-line arguments */
{
int x, y; /* Current coordinate in image */
short line[512]; /* Line to dither */
unsigned char pixels[512], /* Dither pixels */
*pixptr; /* Pointer in line */
int output; /* Output pixel */
cups_lut_t *lut; /* Dither lookup table */
cups_dither_t *dither; /* Dither state */
int nlutvals; /* Number of lookup values */
float lutvals[16]; /* Lookup values */
int pixvals[16]; /* Pixel values */
/*
* See if we have lookup table values on the command-line...
*/
if (argc > 1)
{
/*
* Yes, collect them...
*/
nlutvals = 0;
for (x = 1; x < argc; x ++)
if (isdigit(argv[x][0]) && nlutvals < 16)
{
pixvals[nlutvals] = atoi(argv[x]);
lutvals[nlutvals] = atof(argv[x]) / 255.0;
nlutvals ++;
}
else
usage();
/*
* See if we have at least 2 values...
*/
if (nlutvals < 2)
usage();
}
else
{
/*
* Otherwise use the default 2-entry LUT with values of 0 and 255...
*/
nlutvals = 2;
lutvals[0] = 0.0;
lutvals[1] = 1.0;
pixvals[0] = 0;
pixvals[1] = 255;
}
/*
* Create the lookup table and dither state...
*/
lut = cupsLutNew(nlutvals, lutvals);
dither = cupsDitherNew(512);
/*
* Put out the PGM header for a raw 256x256x8-bit grayscale file...
*/
puts("P5\n512\n512\n255");
/*
* Dither 512 lines, which are written out in 256 image lines...
*/
for (y = 0; y < 512; y ++)
{
/*
* Create the grayscale data for the current line...
*/
for (x = 0; x < 512; x ++)
line[x] = 4095 * ((y / 32) * 16 + x / 32) / 255;
/*
* Dither the line...
*/
cupsDitherLine(dither, lut, line, 1, pixels);
if (y == 0)
{
fputs("DEBUG: pixels =", stderr);
for (x = 0; x < 512; x ++)
fprintf(stderr, " %d", pixels[x]);
fputs("\n", stderr);
}
/*
* Add or set the output pixel values...
*/
for (x = 0, pixptr = pixels; x < 512; x ++, pixptr ++)
{
output = 255 - pixvals[*pixptr];
if (output < 0)
putchar(0);
else
putchar(output);
}
}
/*
* Free the dither state and lookup table...
*/
cupsDitherDelete(dither);
cupsLutDelete(lut);
/*
* Return with no errors...
*/
return (0);
}
/*
* 'usage()' - Show program usage...
*/
void
usage(void)
{
puts("Usage: testdither [val1 val2 [... val16]] >filename.ppm");
exit(1);
}
/*
* End of "$Id$".
*/
|
