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comparison Meerwald/dwt.c @ 0:be303a3f5ea8

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import
author Peter Meerwald <pmeerw@cosy.sbg.ac.at>
date Sun, 12 Aug 2007 13:14:34 +0200
parents
children acb6967ee76d
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-1:000000000000 0:be303a3f5ea8
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 /* memory leak here - there is no function unload_filters() */
22 dwt_allfilters = load_filters(filter_file);
23 if (!dwt_allfilters) {
24 fprintf(stderr, "init_dwt(): unable to open filter definition file %s\n", filter_file);
25 return;
26 }
27 }
28
29 #ifdef DEBUG
30 if (level <= 0 || level > rint(log(MIN(cols, rows))/log(2.0)) - 2) {
31 fprintf(stderr, "init_dwt(): level parameter does not match image width/height\n");
32 return;
33 }
34 #endif
35
36 if (dwt_filters && level != dwt_levels) {
37 free(dwt_filters);
38 dwt_filters = NULL;
39 }
40
41 dwt_levels = level;
42
43 if (!dwt_filters)
44 dwt_filters = calloc(level + 1, sizeof(FilterGH));
45
46 for (i = 0; i < level + 1; i++)
47 dwt_filters[i] = (dwt_allfilters->filter)[filter];
48
49 dwt_filter = filter;
50 dwt_method = method;
51 dwt_cols = cols;
52 dwt_rows = rows;
53 }
54
55 Image_tree fdwt(gray **pixels) {
56 Image image;
57 Image_tree tree;
58 int i, j;
59
60 image = new_image(dwt_cols, dwt_rows);
61
62 for (i = 0; i < dwt_rows; i++)
63 for (j = 0; j < dwt_cols; j++)
64 set_pixel(image, j, i, pixels[i][j]);
65
66 tree = wavelettransform(image, dwt_levels, dwt_filters, dwt_method);
67 free_image(image);
68
69 return tree;
70 }
71
72 Image_tree fdwt_wp(gray **pixels) {
73 Image image;
74 Image_tree tree;
75 int i, j;
76
77 image = new_image(dwt_cols, dwt_rows);
78
79 for (i = 0; i < dwt_rows; i++)
80 for (j = 0; j < dwt_cols; j++)
81 set_pixel(image, j, i, pixels[i][j]);
82
83 tree = wavelettransform_wp(image, dwt_levels, dwt_filters, dwt_method);
84 free_image(image);
85
86 return tree;
87 }
88
89 void idwt(Image_tree dwts, gray **pixels) {
90 Image image;
91 int i, j;
92
93 image = inv_transform(dwts, dwt_filters, dwt_method + 1);
94
95 for (i = 0; i < dwt_rows; i++)
96 for (j = 0; j < dwt_cols; j++)
97 pixels[i][j] = PIXELRANGE((int) (get_pixel(image, j, i) + 0.5));
98
99 free_image(image);
100 }
101
102 void idwt_wp(Image_tree dwts, gray **pixels) {
103 Image image;
104 int i, j;
105
106 image = inv_transform(dwts, dwt_filters, dwt_method + 1);
107
108 for (i = 0; i < dwt_rows; i++)
109 for (j = 0; j < dwt_cols; j++)
110 pixels[i][j] = PIXELRANGE((int) (get_pixel(image, j, i) + 0.5));
111
112 free_image(image);
113 }
114
115 int gen_pollen_filter(double *filter, double alpha, double beta, int which) {
116 int i, j, k, filterlength;
117 double tf[6];
118
119 /* parameter alpha, beta have to be in range -Pi .. Pi */
120 if (alpha < -M_PI || alpha >= M_PI) {
121 fprintf(stderr, "alpha %f out of range\n", alpha);
122 return -1;
123 }
124
125 if (beta < -M_PI || beta >= M_PI) {
126 fprintf(stderr, "beta %f out of range\n", beta);
127 return -1;
128 }
129
130 /* generate Pollen filter coefficients, see http://www.dfw.net/~cody for details */
131 tf[0] = ((1.0 + cos(alpha) + sin(alpha)) * (1.0 - cos(beta) - sin(beta)) + 2.0 * sin(beta) * cos(alpha)) / 4.0;
132 tf[1] = ((1.0 - cos(alpha) + sin(alpha)) * (1.0 + cos(beta) - sin(beta)) - 2.0 * sin(beta) * cos(alpha)) / 4.0;
133 tf[2] = (1.0 + cos(alpha - beta) + sin(alpha - beta)) / 2.0;
134 tf[3] = (1.0 + cos(alpha - beta) - sin(alpha - beta)) / 2.0;
135 tf[4] = 1.0 - tf[0] - tf[2];
136 tf[5] = 1.0 - tf[1] - tf[3];
137
138 /* set close-to-zero filter coefficients to zero */
139 for (i = 0; i < 6; i++)
140 if (fabs(tf[i]) < 1.0e-15) tf[i] = 0.0;
141
142 /* find the first non-zero wavelet coefficient */
143 i = 0;
144 while (tf[i] == 0.0) i++;
145
146 /* find the last non-zero wavelet coefficient */
147 j = 5;
148 while (tf[j] == 0.0) j--;
149
150 filterlength = j - i + 1;
151 for (k = 0; k < filterlength; k++)
152 switch (which) {
153 case FILTERH:
154 filter[k] = tf[j--] / 2.0;
155 break;
156 case FILTERG:
157 filter[k] = (double) (((i & 0x01) * 2) - 1) * tf[i++] / 2.0;
158 break;
159 case FILTERHi:
160 filter[k] = tf[j--];
161 break;
162 case FILTERGi:
163 filter[k] = (double) (((i & 0x01) * 2) - 1) * tf[i++];
164 break;
165 default:
166 return -1;
167 }
168
169 while (k < 6)
170 filter[k++] = 0.0;
171
172 return filterlength;
173 }
174
175 void dwt_pollen_filter(double alpha, double beta) {
176 FilterGH filter;
177 int i;
178
179 filter = malloc(sizeof(struct FilterGHStruct));
180 #ifdef DEBUG
181 if (!filter) {
182 fprintf(stderr, "dwt_pollen_filter(): malloc failed()\n");
183 return;
184 }
185 #endif
186
187 filter->type = FTOther;
188 filter->name = "pollen";
189
190 filter->g = new_filter(6);
191 filter->g->type = FTSymm;
192 filter->g->hipass = 1;
193 filter->g->len = gen_pollen_filter(filter->g->data, alpha, beta, FILTERG);
194 filter->g->start = -filter->g->len / 2;
195 filter->g->end = filter->g->len / 2 - 1;
196
197 filter->h = new_filter(6);
198 filter->h->type = FTSymm;
199 filter->h->hipass = 0;
200 filter->h->len = gen_pollen_filter(filter->h->data, alpha, beta, FILTERH);
201 filter->h->start = -filter->h->len / 2;
202 filter->h->end = filter->h->len / 2 - 1;
203
204 filter->gi = new_filter(6);
205 filter->gi->type = FTSymm;
206 filter->gi->hipass = 1;
207 filter->gi->len = gen_pollen_filter(filter->gi->data, alpha, beta, FILTERGi);
208 filter->gi->start = -filter->gi->len / 2;
209 filter->gi->end = filter->gi->len / 2 - 1;
210
211 filter->hi = new_filter(6);
212 filter->hi->type = FTSymm;
213 filter->hi->hipass = 0;
214 filter->hi->len = gen_pollen_filter(filter->hi->data, alpha, beta, FILTERHi);
215 filter->hi->start = -filter->hi->len / 2;
216 filter->hi->end = filter->hi->len / 2 - 1;
217
218 #ifdef DEBUG
219 if (dwt_levels <= 0) {
220 fprintf(stderr, "dwt_pollen_filter(): level invalid - set to zero\n");
221 return;
222 }
223 #endif
224
225 #ifdef DEBUG
226 if (!dwt_filters) {
227 fprintf(stderr, "dwt_pollen_filter(): wm_dwt not initialized, call init_dwt() first\n");
228 return;
229 }
230 #endif
231
232 for (i = 0; i < dwt_levels + 1; i++)
233 dwt_filters[i] = filter;
234 }
235
236 int gen_param_filter(double *filter, int n, double alpha[], int which) {
237 int i, j, k, filterlength;
238 double *tf, *t;
239
240 tf = malloc(2 * (n + 1) * sizeof(double));
241 t = malloc(2 * (n + 1) * sizeof(double));
242 if (!tf) {
243 fprintf(stderr, "gen_param_filter(): malloc() failed\n");
244 return -1;
245 }
246
247 tf[0] = 1.0 / sqrt(2.0);
248 tf[1] = 1.0 / sqrt(2.0);
249
250 for (k = 0; k < n; k++) {
251 for (i = 0; i < 2 * (k + 2); i++) {
252
253 #define H(X) (((X) < 0 || (X) >= 2 * (k + 1)) ? 0.0 : tf[X])
254
255 t[i] = 0.5 * (H(i - 2) + H(i) +
256 cos(alpha[k]) * (H(i - 2) - H(i)) +
257 (i & 1 ? -1.0 : 1.0) * sin(alpha[k]) * (H(2 * (k + 2) - i - 1) - H(2 * (k + 2) - i - 3)));
258 }
259 for (i = 0; i < 2 * (k + 2); i++) tf[i] = t[i];
260 }
261
262 /* set close-to-zero filter coefficients to zero */
263 for (i = 0; i < 2 * (n + 1) ; i++)
264 if (fabs(tf[i]) < 1.0e-15) tf[i] = 0.0;
265
266 /* find the first non-zero wavelet coefficient */
267 i = 0;
268 while (tf[i] == 0.0) i++;
269
270 /* find the last non-zero wavelet coefficient */
271 j = 2 * (n + 1) - 1;
272 while (tf[j] == 0.0) j--;
273
274 filterlength = j - i + 1;
275 for (k = 0; k < filterlength; k++)
276 switch (which) {
277 case FILTERG:
278 case FILTERGi:
279 filter[k] = (double) (((i+1 & 0x01) * 2) - 1) * tf[i++];
280 break;
281 case FILTERH:
282 case FILTERHi:
283 filter[k] = tf[j--];
284 break;
285 default:
286 return -1;
287 }
288
289 while (k < 2 * (n + 1))
290 filter[k++] = 0.0;
291
292 return filterlength;
293 }
294
295 void dwt_param_filter(double alpha[], int n) {
296 FilterGH filter;
297 int i;
298
299 filter = malloc(sizeof(struct FilterGHStruct));
300 #ifdef DEBUG
301 if (!filter) {
302 fprintf(stderr, "dwt_param_filter(): malloc failed()\n");
303 return;
304 }
305 #endif
306
307 filter->type = FTOrtho;
308 filter->name = "param";
309
310 filter->g = new_filter(2 * (n + 1));
311 filter->g->type = FTSymm;
312 filter->g->hipass = 1;
313 filter->g->len = gen_param_filter(filter->g->data, n, alpha, FILTERG);
314 filter->g->start = -filter->g->len / 2;
315 filter->g->end = filter->g->len / 2 - 1;
316
317 filter->h = new_filter(2 * (n + 1));
318 filter->h->type = FTSymm;
319 filter->h->hipass = 0;
320 filter->h->len = gen_param_filter(filter->h->data, n, alpha, FILTERH);
321 filter->h->start = -filter->h->len / 2;
322 filter->h->end = filter->h->len / 2 - 1;
323
324 #ifdef DEBUG
325 if (dwt_levels <= 0) {
326 fprintf(stderr, "dwt_pollen_filter(): level invalid - set to zero\n");
327 return;
328 }
329 #endif
330
331 #ifdef DEBUG
332 if (!dwt_filters) {
333 fprintf(stderr, "dwt_pollen_filter(): wm_dwt not initialized, call init_dwt() first\n");
334 return;
335 }
336 #endif
337
338 for (i = 0; i < dwt_levels + 1; i++)
339 dwt_filters[i] = filter;
340 }
341
342 void done_dwt() {
343 }

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