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comparison Meerwald-dir/wm_xie_d.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_d.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 // inverse watermarking transformation, extract embedded bit, check quantization boundaries
9 double wm_transform(double alpha, double f1, double f2, double f3) {
10 double s = alpha * (fabs(f3) - fabs(f1)) / 2.0;
11 double l = f1;
12 int x;
13
14 x = 0;
15 while (l < f2) {
16 l += s;
17 x++;
18 }
19
20 if (fabs(l - s - f2) < fabs(l-f2))
21 return (x+1) % 2;
22 else
23 return (x) % 2;
24 }
25
26 void usage(void) {
27 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);
28 fprintf(stderr, "\t-a n\t\tembedding strength (default 0.05)\n");
29 fprintf(stderr, "\t-e n\t\twavelet filtering method\n");
30 fprintf(stderr, "\t-f n\t\tfilter number\n");
31 fprintf(stderr, "\t-F file\t\tfilter definition file\n");
32 fprintf(stderr, "\t-l n\t\tembedding level\n");
33 fprintf(stderr, "\t-h\t\tprint usage\n");
34 fprintf(stderr, "\t-o file\t\textracted signature file\n");
35 fprintf(stderr, "\t-s file\t\tsignature to embed in input image\n");
36 fprintf(stderr, "\t-v n\t\tverbosity level\n");
37 exit(0);
38 }
39
40 int main(int argc, char *argv[]) {
41
42 FILE *in = stdin;
43 FILE *out = stdout;
44 FILE *sig = NULL;
45
46 char output_name[MAXPATHLEN] = "(stdout)";
47 char input_name[MAXPATHLEN] = "(stdin)";
48 char signature_name[MAXPATHLEN];
49
50 int c, n;
51 int row, col;
52
53 double alpha = 0.0;
54 int filter = 0;
55 int method = -1;
56 int level = 0;
57 char filter_name[MAXPATHLEN] = "";
58
59 int seed;
60 int verbose = 0;
61
62 gray **image;
63 Image_tree dwts, p;
64
65 gray maxval;
66 int rows, cols, format;
67
68 progname = argv[0];
69
70 pgm_init(&argc, argv); wm_init2();
71
72 while ((c = getopt(argc, argv, "a:e:f:F:h?l:o:s:v:")) != EOF) {
73 switch (c) {
74 case 'e':
75 method = atoi(optarg);
76 if (method < 0) {
77 fprintf(stderr, "%s: wavelet filtering method %d out of range\n", progname, method);
78 exit(1);
79 }
80 break;
81 case 'f':
82 filter = atoi(optarg);
83 if (filter <= 0) {
84 fprintf(stderr, "%s: filter number %d out of range\n", progname, filter);
85 exit(1);
86 }
87 break;
88 case 'F':
89 strcpy(filter_name, optarg);
90 break;
91 case 'h':
92 case '?':
93 usage();
94 break;
95 case 'l':
96 level = atoi(optarg);
97 if (level < 1) {
98 fprintf(stderr, "%s: embedding level out of range\n", progname);
99 exit(1);
100 }
101 break;
102 case 'o':
103 if ((out = fopen(optarg, "wb")) == NULL) {
104 fprintf(stderr, "%s: unable to open output file %s\n", progname, optarg);
105 exit(1);
106 }
107 strcpy(output_name, optarg);
108 break;
109 case 'a':
110 alpha = atof(optarg);
111 if (alpha <= 0.0) {
112 fprintf(stderr, "%s: embedding strength factor %f out of range\n", progname, alpha);
113 exit(1);
114 }
115 break;
116 case 's':
117 if ((sig = fopen(optarg, "r")) == NULL) {
118 fprintf(stderr, "%s: unable to open signature file %s\n", progname, optarg);
119 exit(1);
120 }
121 strcpy(signature_name, optarg);
122 break;
123 case 'v':
124 verbose = atoi(optarg);
125 if (verbose < 0) {
126 fprintf(stderr, "%s: verbosity level %d out of range\n", progname, verbose);
127 exit(1);
128 }
129 break;
130 }
131 }
132
133 argc -= optind;
134 argv += optind;
135
136 if (argc > 1) {
137 usage();
138 exit(1);
139 }
140
141 if (argc == 1 && *argv[0] != '-') {
142 if ((in = fopen(argv[0], "rb")) == NULL) {
143 fprintf(stderr, "%s: unable to open input file %s\n", progname, argv[0]);
144 exit(1);
145 }
146 else
147 strcpy(input_name, argv[0]);
148 }
149
150 if (sig) {
151 char line[32];
152 fgets(line, sizeof(line), sig);
153 if (strspn(line, "XESG") >= 4) {
154 fscanf(sig, "%d\n", &nbit_signature);
155 if (alpha == 0.0)
156 fscanf(sig, "%lf\n", &alpha);
157 else
158 fscanf(sig, "%*f\n");
159 if (method < 0)
160 fscanf(sig, "%d\n", &method);
161 else
162 fscanf(sig, "%*d\n");
163 if (filter == 0)
164 fscanf(sig, "%d\n", &filter);
165 else
166 fscanf(sig, "%*d\n");
167 if (!strcmp(filter_name, ""))
168 fscanf(sig, "%[^\n\r]\n", filter_name);
169 else
170 fscanf(sig, "%*[^\n\r]\n");
171 if (level == 0)
172 fscanf(sig, "%d\n", &level);
173 else
174 fscanf(sig, "%*d\n");
175 fscanf(sig, "%d\n", &seed);
176 srandom(seed);
177 n_signature = NBITSTOBYTES(nbit_signature);
178 fread(signature, sizeof(char), n_signature, sig);
179 fscanf(sig, "\n");
180 }
181 else {
182 fprintf(stderr, "%s: invalid signature file %s\n", progname, signature_name);
183 exit(1);
184 }
185 fclose(sig);
186 }
187 else {
188 fprintf(stderr, "%s: signature file not specified, use -s file option\n", progname);
189 exit(1);
190 }
191
192 pgm_readpgminit(in, &cols, &rows, &maxval, &format);
193 if (verbose > 0)
194 fprintf(stderr, "%s: embedding %d bits with strength %f in\n"
195 " %d x %d host image, decomposition level %d\n",
196 progname, nbit_signature, alpha, cols, rows, level);
197
198 image = pgm_allocarray(cols, rows);
199 for (row = 0; row < rows; row++)
200 pgm_readpgmrow(in, image[row], cols, maxval, format);
201 fclose(in);
202
203 // decomposition of image
204 init_dwt(cols, rows, filter_name, filter, level, method);
205 #ifdef POLLEN_STUFF
206 #include "pollen_stuff.c"
207 #endif
208 #ifdef PARAM_STUFF
209 #include "param_stuff.c"
210 #endif
211
212 dwts = fdwt(image);
213
214 p = dwts;
215
216 // consider each resolution level
217 while (p->level < level)
218 // descend one level
219 p = p->coarse;
220
221 // repeat binary watermark by sliding a 3-pixel window of approximation image
222 n = 0;
223 for (row = 0; row < p->image->height; row++) {
224 for (col = 0; col < p->image->width - 3; col += 3) {
225 double b1, b2, b3;
226 double *f1 = &b1, *f2 = &b2, *f3 = &b3;
227
228 // get all three approximation pixels in window
229 b1 = get_pixel(p->image, col + 0, row);
230 b2 = get_pixel(p->image, col + 1, row);
231 b3 = get_pixel(p->image, col + 2, row);
232
233 // bring selected pixels in ascending order
234 #define SWAP(A, B) {double *t = A; A = B; B = t;}
235 if (*f1 > *f2) SWAP(f1, f2);
236 if (*f2 > *f3) SWAP(f2, f3);
237 if (*f1 > *f2) SWAP(f1, f2);
238
239 set_signature_bit(n, wm_transform(alpha, *f1, *f2, *f3));
240
241 if (verbose > 1)
242 fprintf(stderr, "%s: extracting #%d (= %d) at (%d/%d); %f < %f < %f\n",
243 progname, n, get_signature_bit(n % nbit_signature), col, row, *f1, *f2, *f3);
244
245 n++;
246 }
247 }
248
249 fprintf(out, "XEWM\n");
250 fprintf(out, "%d\n", n);
251 fwrite(signature, sizeof(char), NBITSTOBYTES(n), out);
252 fprintf(out, "\n");
253 fclose(out);
254
255 pgm_freearray(image, rows);
256
257 exit(0);
258 }

Repositories maintained by Peter Meerwald, pmeerw@pmeerw.net.