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comparison Meerwald-dir/wm_xie_e.c @ 24:9f20bce6184e v0.7

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move directories, support netpbm 11
author Peter Meerwald-Stadler <pmeerw@pmeerw.net>
date Fri, 20 Dec 2024 13:08:59 +0100
parents Meerwald/wm_xie_e.c@4987db85cfae
children
comparison
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23:71dd4b96221b 24:9f20bce6184e
1 #include "wm.h"
2 #include "signature.h"
3 #include "dwt.h"
4 #include "netpbm/pgm.h"
5
6 char *progname;
7
8 // watermarking transformation, set median pixel to quantization boundary
9 double wm_transform(double alpha, double f1, double f2, double f3, int x) {
10 double s = alpha * (fabs(f3) - fabs(f1)) / 2.0;
11 double l = x ? (f1 + s) : f1;
12 double f2new;
13
14 while ((l + 2 * s) < f2) l += 2 * s;
15 f2new = ((f2 - l) < (l + 2 * s - f2)) ? l : (l + 2 * s);
16
17 return f2new;
18 }
19
20 void usage(void) {
21 fprintf(stderr, "usage: %s [-a n] [-e n] [-f n] [-F n] [-h] [-l n] [-o file] [-v n] -s file file\n\n", progname);
22 fprintf(stderr, "\t-a n\t\tembedding strength (default 0.05)\n");
23 fprintf(stderr, "\t-e n\t\twavelet filtering method\n");
24 fprintf(stderr, "\t-f n\t\tfilter number\n");
25 fprintf(stderr, "\t-F file\t\tfilter definition file\n");
26 fprintf(stderr, "\t-l n\t\tembedding level\n");
27 fprintf(stderr, "\t-h\t\tprint usage\n");
28 fprintf(stderr, "\t-o file\t\toutput (watermarked) file\n");
29 fprintf(stderr, "\t-s file\t\tsignature to embed in input image\n");
30 fprintf(stderr, "\t-v n\t\tverbosity level\n");
31 exit(0);
32 }
33
34 int main(int argc, char *argv[]) {
35
36 FILE *in = stdin;
37 FILE *out = stdout;
38 FILE *sig = NULL;
39
40 char output_name[MAXPATHLEN] = "(stdout)";
41 char input_name[MAXPATHLEN] = "(stdin)";
42 char signature_name[MAXPATHLEN];
43
44 int c, n;
45 int row, col;
46
47 double alpha = 0.0;
48 int filter = 0;
49 int method = -1;
50 int level = 0;
51 char filter_name[MAXPATHLEN] = "";
52
53 int seed;
54 int verbose = 0;
55
56 gray **image;
57 Image_tree dwts, p;
58
59 gray maxval;
60 int rows, cols, format;
61
62 progname = argv[0];
63
64 pgm_init(&argc, argv); wm_init();
65
66 while ((c = getopt(argc, argv, "a:e:f:F:h?l:o:s:v:")) != EOF) {
67 switch (c) {
68 case 'e':
69 method = atoi(optarg);
70 if (method < 0) {
71 fprintf(stderr, "%s: wavelet filtering method %d out of range\n", progname, method);
72 exit(1);
73 }
74 break;
75 case 'f':
76 filter = atoi(optarg);
77 if (filter <= 0) {
78 fprintf(stderr, "%s: filter number %d out of range\n", progname, filter);
79 exit(1);
80 }
81 break;
82 case 'F':
83 strcpy(filter_name, optarg);
84 break;
85 case 'h':
86 case '?':
87 usage();
88 break;
89 case 'l':
90 level = atoi(optarg);
91 if (level < 1) {
92 fprintf(stderr, "%s: embedding level out of range\n", progname);
93 exit(1);
94 }
95 break;
96 case 'o':
97 if ((out = fopen(optarg, "wb")) == NULL) {
98 fprintf(stderr, "%s: unable to open output file %s\n", progname, optarg);
99 exit(1);
100 }
101 strcpy(output_name, optarg);
102 break;
103 case 'a':
104 alpha = atof(optarg);
105 if (alpha <= 0.0) {
106 fprintf(stderr, "%s: embedding strength factor %f out of range\n", progname, alpha);
107 exit(1);
108 }
109 break;
110 case 's':
111 if ((sig = fopen(optarg, "r")) == NULL) {
112 fprintf(stderr, "%s: unable to open signature file %s\n", progname, optarg);
113 exit(1);
114 }
115 strcpy(signature_name, optarg);
116 break;
117 case 'v':
118 verbose = atoi(optarg);
119 if (verbose < 0) {
120 fprintf(stderr, "%s: verbosity level %d out of range\n", progname, verbose);
121 exit(1);
122 }
123 break;
124 }
125 }
126
127 argc -= optind;
128 argv += optind;
129
130 if (argc > 1) {
131 usage();
132 exit(1);
133 }
134
135 if (argc == 1 && *argv[0] != '-') {
136 if ((in = fopen(argv[0], "rb")) == NULL) {
137 fprintf(stderr, "%s: unable to open input file %s\n", progname, argv[0]);
138 exit(1);
139 }
140 else
141 strcpy(input_name, argv[0]);
142 }
143
144 if (sig) {
145 char line[32];
146 fgets(line, sizeof(line), sig);
147 if (strspn(line, "XESG") >= 4) {
148 fscanf(sig, "%d\n", &nbit_signature);
149 if (alpha == 0.0)
150 fscanf(sig, "%lf\n", &alpha);
151 else
152 fscanf(sig, "%*f\n");
153 if (method < 0)
154 fscanf(sig, "%d\n", &method);
155 else
156 fscanf(sig, "%*d\n");
157 if (filter == 0)
158 fscanf(sig, "%d\n", &filter);
159 else
160 fscanf(sig, "%*d\n");
161 if (!strcmp(filter_name, ""))
162 fscanf(sig, "%[^\n\r]\n", filter_name);
163 else
164 fscanf(sig, "%*[^\n\r]\n");
165 if (level == 0)
166 fscanf(sig, "%d\n", &level);
167 else
168 fscanf(sig, "%*d\n");
169 fscanf(sig, "%d\n", &seed);
170 srandom(seed);
171 n_signature = NBITSTOBYTES(nbit_signature);
172 fread(signature, sizeof(char), n_signature, sig);
173 fscanf(sig, "\n");
174 }
175 else {
176 fprintf(stderr, "%s: invalid signature file %s\n", progname, signature_name);
177 exit(1);
178 }
179 fclose(sig);
180 }
181 else {
182 fprintf(stderr, "%s: signature file not specified, use -s file option\n", progname);
183 exit(1);
184 }
185
186 pgm_readpgminit(in, &cols, &rows, &maxval, &format);
187
188 if (verbose > 0)
189 fprintf(stderr, "%s: embedding %d bits with strength %f in\n"
190 " %d x %d host image, decomposition level %d\n",
191 progname, nbit_signature, alpha, cols, rows, level);
192
193 image = pgm_allocarray(cols, rows);
194
195 for (row = 0; row < rows; row++)
196 pgm_readpgmrow(in, image[row], cols, maxval, format);
197
198 fclose(in);
199
200 // decomposition of image
201 init_dwt(cols, rows, filter_name, filter, level, method);
202 #ifdef POLLEN_STUFF
203 #include "pollen_stuff.c"
204 #endif
205 #ifdef PARAM_STUFF
206 #include "param_stuff.c"
207 #endif
208
209 dwts = fdwt(image);
210
211 p = dwts;
212
213 // consider each resolution level
214 while (p->level < level)
215 // descend one level
216 p = p->coarse;
217
218 // repeat binary watermark by sliding a 3-pixel window of approximation image
219 n = 0;
220 for (row = 0; row < p->image->height; row++) {
221 for (col = 0; col < p->image->width - 3; col += 3) {
222 double b1, b2, b3;
223 double *f1 = &b1, *f2 = &b2, *f3 = &b3;
224 double f2new;
225
226 // get all three approximation pixels in window
227 b1 = get_pixel(p->image, col + 0, row);
228 b2 = get_pixel(p->image, col + 1, row);
229 b3 = get_pixel(p->image, col + 2, row);
230
231 // bring selected pixels in ascending order
232 #define SWAP(A, B) {double *t = A; A = B; B = t;}
233 if (*f1 > *f2) SWAP(f1, f2);
234 if (*f2 > *f3) SWAP(f2, f3);
235 if (*f1 > *f2) SWAP(f1, f2);
236
237 // apply watermarking transformation (modify median pixel)
238 f2new = wm_transform(alpha, *f1, *f2, *f3, get_signature_bit(n % nbit_signature));
239
240 if (verbose > 1)
241 fprintf(stderr, "%s: embedding #%d (= %d) at (%d/%d); %f < %f -> %f < %f\n",
242 progname, n, get_signature_bit(n % nbit_signature), col, row, *f1, *f2, f2new, *f3);
243
244 *f2 = f2new;
245
246 // write modified pixel
247 set_pixel(p->image, col + 0, row, b1);
248 set_pixel(p->image, col + 1, row, b2);
249 set_pixel(p->image, col + 2, row, b3);
250
251 n++;
252 }
253 }
254
255
256 // skip over some pixels
257
258 idwt(dwts, image);
259
260 pgm_writepgminit(out, cols, rows, maxval, 0);
261
262 for (row = 0; row < rows; row++)
263 pgm_writepgmrow(out, image[row], cols, maxval, 0);
264
265 fclose(out);
266
267 pgm_freearray(image, rows);
268
269 exit(0);
270 }

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