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comparison Meerwald-dir/dwt.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/dwt.c@1906e659edd0
children
comparison
equal deleted inserted replaced
23:71dd4b96221b 24:9f20bce6184e
1 #include "wm.h"
2 #include "dwt.h"
3
4 char filter_file[MAXPATHLEN] = "";
5 AllFilters dwt_allfilters;
6 FilterGH *dwt_filters = NULL;
7 int dwt_method;
8 int dwt_cols;
9 int dwt_rows;
10 int dwt_levels;
11 int dwt_filter;
12
13 void init_dwt(int cols, int rows, const char *filter_name, int filter, int level, int method) {
14 int i;
15
16 if (strcmp(filter_file, filter_name)) {
17 if (filter_name)
18 strcpy(filter_file, filter_name);
19 else
20 strcpy(filter_file, "filter.dat");
21
22 /* memory leak here - there is no function unload_filters() */
23 dwt_allfilters = load_filters(filter_file);
24
25 if (!dwt_allfilters) {
26 fprintf(stderr, "init_dwt(): unable to open filter definition file %s\n", filter_file);
27 return;
28 }
29 }
30
31 #ifdef DEBUG
32 if (level <= 0 || level > rint(log(MIN(cols, rows))/log(2.0)) - 2) {
33 fprintf(stderr, "init_dwt(): level parameter does not match image width/height\n");
34 return;
35 }
36 #endif
37
38 if (dwt_filters && level != dwt_levels) {
39 free(dwt_filters);
40 dwt_filters = NULL;
41 }
42
43 dwt_levels = level;
44
45 if (!dwt_filters)
46 dwt_filters = calloc(level + 1, sizeof(FilterGH));
47
48 for (i = 0; i < level + 1; i++)
49 dwt_filters[i] = (dwt_allfilters->filter)[filter];
50
51 dwt_filter = filter;
52 dwt_method = method;
53 dwt_cols = cols;
54 dwt_rows = rows;
55 }
56
57 Image_tree fdwt(gray **pixels) {
58 Image image;
59 Image_tree tree;
60 int i, j;
61
62 image = new_image(dwt_cols, dwt_rows);
63
64 for (i = 0; i < dwt_rows; i++)
65 for (j = 0; j < dwt_cols; j++)
66 set_pixel(image, j, i, pixels[i][j]);
67
68 tree = wavelettransform(image, dwt_levels, dwt_filters, dwt_method);
69 free_image(image);
70
71 return tree;
72 }
73
74 Image_tree fdwt_wp(gray **pixels) {
75 Image image;
76 Image_tree tree;
77 int i, j;
78
79 image = new_image(dwt_cols, dwt_rows);
80
81 for (i = 0; i < dwt_rows; i++)
82 for (j = 0; j < dwt_cols; j++)
83 set_pixel(image, j, i, pixels[i][j]);
84
85 tree = wavelettransform_wp(image, dwt_levels, dwt_filters, dwt_method);
86 free_image(image);
87
88 return tree;
89 }
90
91 void idwt(Image_tree dwts, gray **pixels) {
92 Image image;
93 int i, j;
94
95 image = inv_transform(dwts, dwt_filters, dwt_method + 1);
96
97 for (i = 0; i < dwt_rows; i++)
98 for (j = 0; j < dwt_cols; j++)
99 pixels[i][j] = PIXELRANGE((int) (get_pixel(image, j, i) + 0.5));
100
101 free_image(image);
102 }
103
104 void idwt_wp(Image_tree dwts, gray **pixels) {
105 Image image;
106 int i, j;
107
108 image = inv_transform(dwts, dwt_filters, dwt_method + 1);
109
110 for (i = 0; i < dwt_rows; i++)
111 for (j = 0; j < dwt_cols; j++)
112 pixels[i][j] = PIXELRANGE((int) (get_pixel(image, j, i) + 0.5));
113
114 free_image(image);
115 }
116
117 int gen_pollen_filter(double *filter, double alpha, double beta, int which) {
118 int i, j, k, filterlength;
119 double tf[6];
120
121 /* parameter alpha, beta have to be in range -Pi .. Pi */
122 if (alpha < -M_PI || alpha >= M_PI) {
123 fprintf(stderr, "alpha %f out of range\n", alpha);
124 return -1;
125 }
126
127 if (beta < -M_PI || beta >= M_PI) {
128 fprintf(stderr, "beta %f out of range\n", beta);
129 return -1;
130 }
131
132 /* generate Pollen filter coefficients, see http://www.dfw.net/~cody for details */
133 tf[0] = ((1.0 + cos(alpha) + sin(alpha)) * (1.0 - cos(beta) - sin(beta)) + 2.0 * sin(beta) * cos(alpha)) / 4.0;
134 tf[1] = ((1.0 - cos(alpha) + sin(alpha)) * (1.0 + cos(beta) - sin(beta)) - 2.0 * sin(beta) * cos(alpha)) / 4.0;
135 tf[2] = (1.0 + cos(alpha - beta) + sin(alpha - beta)) / 2.0;
136 tf[3] = (1.0 + cos(alpha - beta) - sin(alpha - beta)) / 2.0;
137 tf[4] = 1.0 - tf[0] - tf[2];
138 tf[5] = 1.0 - tf[1] - tf[3];
139
140 /* set close-to-zero filter coefficients to zero */
141 for (i = 0; i < 6; i++)
142 if (fabs(tf[i]) < 1.0e-15) tf[i] = 0.0;
143
144 /* find the first non-zero wavelet coefficient */
145 i = 0;
146 while (tf[i] == 0.0) i++;
147
148 /* find the last non-zero wavelet coefficient */
149 j = 5;
150 while (tf[j] == 0.0) j--;
151
152 filterlength = j - i + 1;
153 for (k = 0; k < filterlength; k++)
154 switch (which) {
155 case FILTERH:
156 filter[k] = tf[j--] / 2.0;
157 break;
158 case FILTERG:
159 filter[k] = (double) (((i & 0x01) * 2) - 1) * tf[i] / 2.0;
160 i++;
161 break;
162 case FILTERHi:
163 filter[k] = tf[j--];
164 break;
165 case FILTERGi:
166 filter[k] = (double) (((i & 0x01) * 2) - 1) * tf[i];
167 i++;
168 break;
169 default:
170 return -1;
171 }
172
173 while (k < 6)
174 filter[k++] = 0.0;
175
176 return filterlength;
177 }
178
179 void dwt_pollen_filter(double alpha, double beta) {
180 FilterGH filter;
181 int i;
182
183 filter = malloc(sizeof(struct FilterGHStruct));
184 #ifdef DEBUG
185 if (!filter) {
186 fprintf(stderr, "dwt_pollen_filter(): malloc failed()\n");
187 return;
188 }
189 #endif
190
191 filter->type = FTOther;
192 filter->name = "pollen";
193
194 filter->g = new_filter(6);
195 filter->g->type = FTSymm;
196 filter->g->hipass = 1;
197 filter->g->len = gen_pollen_filter(filter->g->data, alpha, beta, FILTERG);
198 filter->g->start = -filter->g->len / 2;
199 filter->g->end = filter->g->len / 2 - 1;
200
201 filter->h = new_filter(6);
202 filter->h->type = FTSymm;
203 filter->h->hipass = 0;
204 filter->h->len = gen_pollen_filter(filter->h->data, alpha, beta, FILTERH);
205 filter->h->start = -filter->h->len / 2;
206 filter->h->end = filter->h->len / 2 - 1;
207
208 filter->gi = new_filter(6);
209 filter->gi->type = FTSymm;
210 filter->gi->hipass = 1;
211 filter->gi->len = gen_pollen_filter(filter->gi->data, alpha, beta, FILTERGi);
212 filter->gi->start = -filter->gi->len / 2;
213 filter->gi->end = filter->gi->len / 2 - 1;
214
215 filter->hi = new_filter(6);
216 filter->hi->type = FTSymm;
217 filter->hi->hipass = 0;
218 filter->hi->len = gen_pollen_filter(filter->hi->data, alpha, beta, FILTERHi);
219 filter->hi->start = -filter->hi->len / 2;
220 filter->hi->end = filter->hi->len / 2 - 1;
221
222 #ifdef DEBUG
223 if (dwt_levels <= 0) {
224 fprintf(stderr, "dwt_pollen_filter(): level invalid - set to zero\n");
225 return;
226 }
227 #endif
228
229 #ifdef DEBUG
230 if (!dwt_filters) {
231 fprintf(stderr, "dwt_pollen_filter(): wm_dwt not initialized, call init_dwt() first\n");
232 return;
233 }
234 #endif
235
236 for (i = 0; i < dwt_levels + 1; i++)
237 dwt_filters[i] = filter;
238 }
239
240 int gen_param_filter(double *filter, int n, double alpha[], int which) {
241 int i, j, k, filterlength;
242 double *tf, *t;
243
244 tf = malloc(2 * (n + 1) * sizeof(double));
245 t = malloc(2 * (n + 1) * sizeof(double));
246 if (!tf) {
247 fprintf(stderr, "gen_param_filter(): malloc() failed\n");
248 return -1;
249 }
250
251 tf[0] = 1.0 / sqrt(2.0);
252 tf[1] = 1.0 / sqrt(2.0);
253
254 for (k = 0; k < n; k++) {
255 for (i = 0; i < 2 * (k + 2); i++) {
256
257 #define H(X) (((X) < 0 || (X) >= 2 * (k + 1)) ? 0.0 : tf[X])
258
259 t[i] = 0.5 * (H(i - 2) + H(i) +
260 cos(alpha[k]) * (H(i - 2) - H(i)) +
261 (i & 1 ? -1.0 : 1.0) * sin(alpha[k]) * (H(2 * (k + 2) - i - 1) - H(2 * (k + 2) - i - 3)));
262 }
263 for (i = 0; i < 2 * (k + 2); i++) tf[i] = t[i];
264 }
265
266 /* set close-to-zero filter coefficients to zero */
267 for (i = 0; i < 2 * (n + 1) ; i++)
268 if (fabs(tf[i]) < 1.0e-15) tf[i] = 0.0;
269
270 /* find the first non-zero wavelet coefficient */
271 i = 0;
272 while (tf[i] == 0.0) i++;
273
274 /* find the last non-zero wavelet coefficient */
275 j = 2 * (n + 1) - 1;
276 while (tf[j] == 0.0) j--;
277
278 filterlength = j - i + 1;
279 for (k = 0; k < filterlength; k++)
280 switch (which) {
281 case FILTERG:
282 case FILTERGi:
283 filter[k] = (double) ((((i+1) & 0x01) * 2) - 1) * tf[i];
284 i++;
285 break;
286 case FILTERH:
287 case FILTERHi:
288 filter[k] = tf[j--];
289 break;
290 default:
291 return -1;
292 }
293
294 while (k < 2 * (n + 1))
295 filter[k++] = 0.0;
296
297 return filterlength;
298 }
299
300 void dwt_param_filter(double alpha[], int param_len[]) {
301 FilterGH filter;
302 int i;
303 int param_len_sum = 0;
304
305 #ifdef DEBUG
306 if (dwt_levels <= 0) {
307 fprintf(stderr, "dwt_param_filter(): level invalid - set to zero\n");
308 return;
309 }
310 #endif
311
312 #ifdef DEBUG
313 if (!dwt_filters) {
314 fprintf(stderr, "dwt_param_filter(): wm_dwt not initialized, call init_dwt() first\n");
315 return;
316 }
317 #endif
318
319
320 for (i = 0; i < dwt_levels + 1; i++) {
321
322 filter = malloc(sizeof(struct FilterGHStruct));
323 #ifdef DEBUG
324 if (!filter) {
325 fprintf(stderr, "dwt_param_filter(): malloc failed()\n");
326 return;
327 }
328 #endif
329
330 filter->type = FTOrtho;
331 filter->name = "param";
332
333 filter->g = new_filter(2 * (param_len[i] + 1));
334 filter->g->type = FTSymm;
335 filter->g->hipass = 1;
336 filter->g->len = gen_param_filter(filter->g->data,
337 param_len[i], &alpha[param_len_sum],
338 FILTERG);
339 filter->g->start = -filter->g->len / 2;
340 filter->g->end = filter->g->len / 2 - 1;
341
342 filter->h = new_filter(2 * (param_len[i] + 1));
343 filter->h->type = FTSymm;
344 filter->h->hipass = 0;
345 filter->h->len = gen_param_filter(filter->h->data,
346 param_len[i], &alpha[param_len_sum],
347 FILTERH);
348 filter->h->start = -filter->h->len / 2;
349 filter->h->end = filter->h->len / 2 - 1;
350
351 filter->gi = 0;
352 filter->hi = 0;
353
354 dwt_filters[i] = filter;
355
356 param_len_sum += param_len[i];
357 }
358 }
359
360 void done_dwt() {
361 }

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