Mercurial > hg > wm
annotate Meerwald/wm_koch_e.c @ 21:1c4ccd635a68 v0.6
ignore *.swp
| author | Peter Meerwald-Stadler <pmeerw@pmeerw.net> |
|---|---|
| date | Sat, 28 Jan 2023 23:57:40 +0100 |
| parents | 3bdb67e76858 |
| children |
| rev | line source |
|---|---|
| 0 | 1 #include "wm.h" |
| 2 #include "dct.h" | |
| 3 #include "signature.h" | |
| 4 #include "coord.h" | |
| 18 | 5 #include "gray.h" |
| 0 | 6 #include "pgm.h" |
| 7 | |
| 8 char *progname; | |
| 9 | |
| 18 | 10 double sign(double x) { |
| 11 if (x >= 0.0) return 1.0; | |
| 12 else return -1.0; | |
| 13 } | |
| 14 | |
| 15 double try_modif(gray **image_block, double **dcts, int c1, int c2, double w1, double w2) { | |
| 16 int i, j; | |
| 17 gray **altered_block; | |
| 18 double **altered_dcts; | |
| 19 double sum; | |
| 20 | |
| 21 altered_block = alloc_grays_8x8(); | |
| 22 altered_dcts = alloc_coeffs_8x8(); | |
| 23 | |
| 24 for (i = 0; i < 8; i++) { | |
| 25 memcpy(altered_dcts[i], dcts[i], sizeof(double) * 8); | |
| 26 } | |
| 27 | |
| 28 // put the changed coefficients back to black | |
| 29 altered_dcts[c1 / NJPEG][c1 % NJPEG] = w1; | |
| 30 altered_dcts[c2 / NJPEG][c2 % NJPEG] = w2; | |
| 31 | |
| 32 dequantize_8x8(altered_dcts); | |
| 33 | |
| 34 idct_block_8x8(altered_dcts, altered_block, 0, 0); | |
| 35 | |
| 36 // compute MSE | |
| 37 sum = 0.0; | |
| 38 for (i = 0; i < 8; i++) { | |
| 39 for (j = 0; j < 8; j++) { | |
| 40 double ib = image_block[i][j]; | |
| 41 double ab = altered_block[i][j]; | |
| 42 sum += (ib - ab) * (ib - ab); | |
| 43 } | |
| 44 } | |
| 45 sum /= 64.0; | |
| 46 | |
| 47 free(altered_block); | |
| 48 free(altered_dcts); | |
| 49 | |
| 50 return sum; | |
| 51 } | |
| 52 | |
| 0 | 53 void usage(void) { |
| 54 fprintf(stderr, "usage: %s [-h] [-l n] [-o file] [-q n] [-v n] -s file file\n", progname); | |
| 55 fprintf(stderr, "\t-h\t\tprint usage\n"); | |
| 56 fprintf(stderr, "\t-l n\t\tsignature robustness factor\n"); | |
| 57 fprintf(stderr, "\t-o file\t\toutput (watermarked) file\n"); | |
| 58 fprintf(stderr, "\t-q n\t\tquantization (JPEG quality) factor\n"); | |
| 59 fprintf(stderr, "\t-s file\t\tsignature to embed in input image\n"); | |
| 60 fprintf(stderr, "\t-v n\t\tverbosity level\n"); | |
| 61 exit(0); | |
| 62 } | |
| 63 | |
| 64 int main(int argc, char *argv[]) { | |
| 65 | |
| 66 FILE *in = stdin; | |
| 67 FILE *out = stdout; | |
| 68 FILE *sig = NULL; | |
| 69 | |
| 70 char signature_name[MAXPATHLEN]; | |
| 71 char input_name[MAXPATHLEN] = "(stdin)"; | |
| 72 char output_name[MAXPATHLEN] = "(stdout)"; | |
| 73 | |
| 74 int c; | |
| 75 int n; | |
| 76 | |
| 77 int seed; | |
| 78 int verbose = 0; | |
| 79 | |
| 80 int rows, cols, format; | |
| 81 gray maxval; | |
| 8 | 82 int row; |
| 0 | 83 |
| 84 int quantization = 0; | |
| 85 double quality = 0.0; | |
| 86 | |
| 87 struct coords *coords; | |
| 88 | |
| 89 gray **image; | |
| 90 double **dcts; | |
| 18 | 91 gray **image_block; |
| 0 | 92 |
| 93 progname = argv[0]; | |
| 94 | |
| 95 pgm_init(&argc, argv); wm_init(); | |
| 96 | |
| 97 while ((c = getopt(argc, argv, "h?i:l:o:q:s:v:")) != EOF) { | |
| 98 switch (c) { | |
| 99 case 'h': | |
| 100 case '?': | |
| 101 usage(); | |
| 102 break; | |
| 103 case 'l': | |
| 104 quality = atof(optarg); | |
| 105 if (quality <= 0.0) { | |
| 106 fprintf(stderr, "%s: signature strength factor %f out of range\n", progname, quality); | |
| 107 exit(1); | |
| 108 } | |
| 109 break; | |
| 110 case 'o': | |
| 111 if ((out = fopen(optarg, "wb")) == NULL) { | |
| 112 fprintf(stderr, "%s: unable to open output file %s\n", progname, optarg); | |
| 113 exit(1); | |
| 114 } | |
| 115 strcpy(output_name, optarg); | |
| 116 break; | |
| 117 case 'q': | |
| 118 quantization = atoi(optarg); | |
| 119 if (quantization <= 0 || quantization > 100) { | |
| 120 fprintf(stderr, "%s: quantization factor %d out of range\n", progname, quantization); | |
| 121 exit(1); | |
| 122 } | |
| 123 break; | |
| 124 case 's': | |
| 125 if ((sig = fopen(optarg, "r")) == NULL) { | |
| 126 fprintf(stderr, "%s: unable to open signature file %s\n", progname, optarg); | |
| 127 exit(1); | |
| 128 } | |
| 129 strcpy(signature_name, optarg); | |
| 130 break; | |
| 131 case 'v': | |
| 132 verbose = atoi(optarg); | |
| 133 if (verbose < 0) { | |
| 134 fprintf(stderr, "%s: verbosity level %d out of range\n", progname, verbose); | |
| 135 exit(1); | |
| 136 } | |
| 137 break; | |
| 138 } | |
| 139 } | |
| 140 | |
| 141 argc -= optind; | |
| 142 argv += optind; | |
| 143 | |
| 144 if (argc > 1) { | |
| 145 usage(); | |
| 146 exit(1); | |
| 147 } | |
| 148 | |
| 8 | 149 if (argc == 1 && *argv[0] != '-') { |
| 0 | 150 if ((in = fopen(argv[0], "rb")) == NULL) { |
| 151 fprintf(stderr, "%s: unable to open input file %s\n", progname, argv[0]); | |
| 152 exit(1); | |
| 153 } | |
| 154 else | |
| 155 strcpy(input_name, argv[0]); | |
| 8 | 156 } |
| 0 | 157 |
| 158 if (sig) { | |
| 159 char line[128]; | |
| 160 fgets(line, sizeof(line), sig); | |
| 161 if (strspn(line, "KCSG") >= 4) { | |
| 162 fscanf(sig, "%d\n", &nbit_signature); | |
| 163 if (quality == 0.0) | |
| 164 fscanf(sig, "%lf\n", &quality); | |
| 165 else | |
|
16
4987db85cfae
fix another scanf() warning
Peter Meerwald <pmeerw@cosy.sbg.ac.at>
parents:
8
diff
changeset
|
166 fscanf(sig, "%*f\n"); |
| 0 | 167 if (quantization == 0) |
| 168 fscanf(sig, "%d\n", &quantization); | |
| 169 else | |
| 170 fscanf(sig, "%*d\n"); | |
| 171 fscanf(sig, "%d\n", &seed); | |
| 172 n_signature = NBITSTOBYTES(nbit_signature); | |
| 173 fread(signature, sizeof(char), n_signature, sig); | |
| 174 fscanf(sig, "\n"); | |
| 175 srandom(seed); | |
| 176 } | |
| 177 else { | |
| 178 fprintf(stderr, "%s: invalid signature file %s\n", progname, signature_name); | |
| 179 exit(1); | |
| 180 } | |
| 181 fclose(sig); | |
| 182 } | |
| 183 else { | |
| 184 fprintf(stderr, "%s: signature file not specified, use -s file option\n", progname); | |
| 185 exit(1); | |
| 186 } | |
| 187 | |
| 188 pgm_readpgminit(in, &cols, &rows, &maxval, &format); | |
| 189 | |
| 190 if (cols % NJPEG) { | |
| 191 fprintf(stderr, "%s: image width %d not a multiple of %d\n", progname, cols, NJPEG); | |
| 192 exit(1); | |
| 193 } | |
| 194 | |
| 195 if (rows % NJPEG) { | |
| 196 fprintf(stderr, "%s: image height %d not a multiple of %d\n", progname, rows, NJPEG); | |
| 197 exit(1); | |
| 198 } | |
| 199 | |
| 200 if ((cols * rows) / (NJPEG * NJPEG) < nbit_signature) { | |
| 201 fprintf(stderr, "%s: image not large enough to embed %d bits of signature\n", progname, nbit_signature); | |
| 202 exit(1); | |
| 203 } | |
| 204 | |
| 205 init_dct_8x8(); | |
| 206 init_quantum_JPEG_lumin(quantization); | |
| 207 | |
| 208 dcts = alloc_coeffs_8x8(); | |
| 18 | 209 image_block = alloc_grays_8x8(); |
| 0 | 210 |
| 211 if ((coords = alloc_coords(nbit_signature)) == NULL) { | |
| 212 fprintf(stderr, "%s: unable to allocate memory\n", progname); | |
| 213 exit(1); | |
| 214 } | |
| 215 | |
| 216 image = pgm_allocarray(cols, rows); | |
| 217 | |
| 218 for (row = 0; row < rows; row++) | |
| 219 pgm_readpgmrow(in, image[row], cols, maxval, format); | |
| 220 | |
| 221 fclose(in); | |
| 222 | |
| 223 // embedding signature bits by modifying two coefficient relationship, | |
| 224 // one bit for each block | |
| 225 n = 0; | |
| 226 while (n < nbit_signature) { | |
| 227 int xb; | |
| 228 int yb; | |
| 229 int c1, c2; | |
| 230 double v1, v2; | |
| 231 double w1, w2; | |
| 18 | 232 double best_w1, best_w2; |
| 233 double diff; | |
| 234 double mod; | |
| 235 double try; | |
| 236 double best_mse; | |
| 237 int no_mse_opt = 0; | |
| 0 | 238 |
| 239 // randomly select a block, check to get distinct blocks | |
| 240 // (don't watermark a block twice) | |
| 241 do { | |
| 242 xb = random() % (cols / NJPEG); | |
| 243 yb = random() % (rows / NJPEG); | |
| 244 } while (add_coord(coords, xb, yb) < 0); | |
| 245 | |
| 246 // do the forward 8x8 DCT of that block | |
| 247 fdct_block_8x8(image, xb * NJPEG, yb * NJPEG, dcts); | |
| 248 | |
| 18 | 249 copy_grays_to_block(image_block, image, xb*NJPEG, yb*NJPEG, NJPEG, NJPEG); |
| 250 | |
| 0 | 251 // randomly select two distinct coefficients from block |
| 252 // only accept coefficients in the middle frequency range | |
| 253 do { | |
| 254 c1 = (random() % (NJPEG * NJPEG - 2)) + 1; | |
| 255 c2 = (random() % (NJPEG * NJPEG - 2)) + 1; | |
| 256 } while (c1 == c2 || !is_middle_frequency_coeff_8x8(c1) || !is_middle_frequency_coeff_8x8(c2)); | |
| 257 | |
| 258 // quantize block according to quantization quality parameter | |
| 259 quantize_8x8(dcts); | |
| 260 | |
| 261 if (verbose > 0) | |
| 262 fprintf(stderr, "%d: quantized DCT block (x %d/y %d), modifying (x %d/y %d), (x %d/y %d) for %s\n", n, xb * NJPEG, yb * NJPEG, c1 % NJPEG, c1 / NJPEG, c2 % NJPEG, c2 / NJPEG, get_signature_bit(n) ? "HIGH" : "LOW"); | |
| 263 if (verbose > 5) | |
| 264 print_coeffs_8x8(dcts); | |
| 265 | |
| 266 v1 = dcts[c1 / NJPEG][c1 % NJPEG]; | |
| 267 v2 = dcts[c2 / NJPEG][c2 % NJPEG]; | |
| 268 | |
| 18 | 269 best_w1 = DBL_MAX, best_w2 = DBL_MAX; |
| 270 try = 0.0; | |
| 271 best_mse = DBL_MAX; | |
| 272 | |
| 0 | 273 diff = fabs(v1) - fabs(v2); |
| 274 | |
| 18 | 275 if (get_signature_bit(n)) |
| 276 mod = fabs(quality - ( fabs(v1) - fabs(v2) )); | |
| 277 else | |
| 278 mod = fabs(quality - (fabs(v2) - fabs(v1))); | |
| 279 | |
| 280 if (verbose > 2) | |
| 281 fprintf(stderr, "%d / %d: %.2f %.2f %.2f | %d\n", xb, yb, diff, v1, v2, get_signature_bit(n)); | |
| 282 | |
| 283 while (try <= mod) { | |
| 0 | 284 w1 = v1; |
| 285 w2 = v2; | |
| 18 | 286 |
| 287 // modify coefficient's relationship to embed signature bit | |
| 288 // using mean square error to minimize error | |
| 289 if (get_signature_bit(n)) { | |
| 290 if (diff < quality) { | |
| 291 // we have to impose the relationship, does not occur naturally | |
| 292 w1 = sign(v1)*(fabs(v1) + mod - try); | |
| 293 w2 = sign(v2)*(fabs(v2) - try); | |
| 294 } | |
| 295 } | |
| 296 else { | |
| 297 if (diff > -quality) { | |
| 298 // force the relationship | |
| 299 w2 = sign(v2)*(fabs(v2) + mod - try); | |
| 300 w1 = sign(v1)*(fabs(v1) - try); | |
| 301 } | |
| 302 } | |
| 303 | |
| 304 double mse = try_modif(image_block, dcts, c1, c2, w1, w2); | |
| 305 if (mse < best_mse) { | |
| 306 best_w1 = w1; | |
| 307 best_w2 = w2; | |
| 308 best_mse = mse; | |
| 309 } | |
| 310 | |
| 311 if (verbose > 2) | |
| 312 fprintf(stderr, "%d / %d: MSE %.2f %.2f; %.2f: %.2f %.2f\n", xb, yb, mse, best_mse, try, w1, w2); | |
| 313 | |
| 314 if (fabs(mse) == 1e-3) | |
| 315 break; | |
| 316 | |
| 317 if (fabs(fabs(w1) - fabs(w2) + quality) > 1e-3) | |
| 318 break; | |
| 319 | |
| 320 if (no_mse_opt) | |
| 321 break; | |
| 322 | |
| 323 try += 0.05; | |
| 0 | 324 } |
| 325 | |
| 326 if (verbose > 1) | |
| 18 | 327 fprintf(stderr, " %f -> %f, %f -> %f\n", v1, best_w1, v2, best_w2); |
| 0 | 328 |
| 329 // put the changed coefficients back to black | |
| 18 | 330 dcts[c1 / NJPEG][c1 % NJPEG] = best_w1; |
| 331 dcts[c2 / NJPEG][c2 % NJPEG] = best_w2; | |
| 0 | 332 |
| 333 // the obvious :-) | |
| 334 dequantize_8x8(dcts); | |
| 335 | |
| 336 // do the inverse DCT on the modified 8x8 block | |
| 337 idct_block_8x8(dcts, image, xb * NJPEG, yb * NJPEG); | |
| 338 | |
| 339 n++; | |
| 340 } | |
| 341 | |
| 18 | 342 free_grays(image_block); |
| 0 | 343 free_coeffs(dcts); |
| 344 | |
| 345 pgm_writepgminit(out, cols, rows, maxval, 0); | |
| 346 for (row = 0; row < rows; row++) | |
| 347 pgm_writepgmrow(out, image[row], cols, maxval, 0); | |
| 348 | |
| 349 fclose(out); | |
| 350 | |
| 351 pgm_freearray(image, rows); | |
| 352 | |
| 353 exit(0); | |
| 354 } |