1 /*
2 * Copyright (C) 2011 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 // pyramid.cpp
18
19 #include <stdio.h>
20 #include <string.h>
21
22 #include "Pyramid.h"
23
24 // We allocate the entire pyramid into one contiguous storage. This makes
25 // cleanup easier than fragmented stuff. In addition, we added a "pitch"
26 // field, so pointer manipulation is much simpler when it would be faster.
allocatePyramidPacked(real levels,real width,real height,real border)27 PyramidShort *PyramidShort::allocatePyramidPacked(real levels,
28 real width, real height, real border)
29 {
30 real border2 = (real) (border << 1);
31 int lines, size = calcStorage(width, height, border2, levels, &lines);
32
33 PyramidShort *img = (PyramidShort *) calloc(sizeof(PyramidShort) * levels
34 + sizeof(short *) * lines +
35 + sizeof(short) * size, 1);
36
37 if (img) {
38 PyramidShort *curr, *last;
39 ImageTypeShort *y = (ImageTypeShort *) &img[levels];
40 ImageTypeShort position = (ImageTypeShort) &y[lines];
41 for (last = (curr = img) + levels; curr < last; curr++) {
42 curr->width = width;
43 curr->height = height;
44 curr->border = border;
45 curr->pitch = (real) (width + border2);
46 curr->ptr = y + border;
47
48 // Assign row pointers
49 for (int j = height + border2; j--; y++, position += curr->pitch) {
50 *y = position + border;
51 }
52
53 width >>= 1;
54 height >>= 1;
55 }
56 }
57
58 return img;
59 }
60
61 // Allocate an image of type short
allocateImage(real width,real height,real border)62 PyramidShort *PyramidShort::allocateImage(real width, real height, real border)
63 {
64 real border2 = (real) (border << 1);
65 PyramidShort *img = (PyramidShort *)
66 calloc(sizeof(PyramidShort) + sizeof(short *) * (height + border2) +
67 sizeof(short) * (width + border2) * (height + border2), 1);
68
69 if (img) {
70 short **y = (short **) &img[1];
71 short *position = (short *) &y[height + border2];
72 img->width = width;
73 img->height = height;
74 img->border = border;
75 img->pitch = (real) (width + border2);
76 img->ptr = y + border;
77 position += border; // Move position down to origin of real image
78
79 // Assign row pointers
80 for (int j = height + border2; j--; y++, position += img->pitch) {
81 *y = position;
82 }
83 }
84
85 return img;
86 }
87
88 // Free the images
freeImage(PyramidShort * image)89 void PyramidShort::freeImage(PyramidShort *image)
90 {
91 if (image != NULL)
92 free(image);
93 }
94
95 // Calculate amount of storage needed taking into account the borders, etc.
calcStorage(real width,real height,real border2,int levels,int * lines)96 unsigned int PyramidShort::calcStorage(real width, real height, real border2, int levels, int *lines)
97 {
98 int size;
99
100 *lines = size = 0;
101
102 while(levels--) {
103 size += (width + border2) * (height + border2);
104 *lines += height + border2;
105 width >>= 1;
106 height >>= 1;
107 }
108
109 return size;
110 }
111
BorderSpread(PyramidShort * pyr,int left,int right,int top,int bot)112 void PyramidShort::BorderSpread(PyramidShort *pyr, int left, int right,
113 int top, int bot)
114 {
115 int off, off2, height, h, w;
116 ImageTypeShort base;
117
118 if (left || right) {
119 off = pyr->border - left;
120 off2 = pyr->width + off + pyr->border - right - 1;
121 h = pyr->border - top;
122 height = pyr->height + (h << 1);
123 base = pyr->ptr[-h] - off;
124
125 // spread in X
126 for (h = height; h--; base += pyr->pitch) {
127 for (w = left; w--;)
128 base[-1 - w] = base[0];
129 for (w = right; w--;)
130 base[off2 + w + 1] = base[off2];
131 }
132 }
133
134 if (top || bot) {
135 // spread in Y
136 base = pyr->ptr[top - pyr->border] - pyr->border;
137 for (h = top; h--; base -= pyr->pitch) {
138 memcpy(base - pyr->pitch, base, pyr->pitch * sizeof(short));
139 }
140
141 base = pyr->ptr[pyr->height + pyr->border - bot] - pyr->border;
142 for (h = bot; h--; base += pyr->pitch) {
143 memcpy(base, base - pyr->pitch, pyr->pitch * sizeof(short));
144 }
145 }
146 }
147
BorderExpandOdd(PyramidShort * in,PyramidShort * out,PyramidShort * scr,int mode)148 void PyramidShort::BorderExpandOdd(PyramidShort *in, PyramidShort *out, PyramidShort *scr,
149 int mode)
150 {
151 int i,j;
152 int off = in->border / 2;
153
154 // Vertical Filter
155 for (j = -off; j < in->height + off; j++) {
156 int j2 = j * 2;
157 int limit = scr->width + scr->border;
158 for (i = -scr->border; i < limit; i++) {
159 int t1 = in->ptr[j][i];
160 int t2 = in->ptr[j+1][i];
161 scr->ptr[j2][i] = (short)
162 ((6 * t1 + (in->ptr[j-1][i] + t2) + 4) >> 3);
163 scr->ptr[j2+1][i] = (short)((t1 + t2 + 1) >> 1);
164 }
165 }
166
167 BorderSpread(scr, 0, 0, 3, 3);
168
169 // Horizontal Filter
170 int limit = out->height + out->border;
171 for (j = -out->border; j < limit; j++) {
172 for (i = -off; i < scr->width + off; i++) {
173 int i2 = i * 2;
174 int t1 = scr->ptr[j][i];
175 int t2 = scr->ptr[j][i+1];
176 out->ptr[j][i2] = (short) (out->ptr[j][i2] +
177 (mode * ((6 * t1 +
178 scr->ptr[j][i-1] + t2 + 4) >> 3)));
179 out->ptr[j][i2+1] = (short) (out->ptr[j][i2+1] +
180 (mode * ((t1 + t2 + 1) >> 1)));
181 }
182 }
183
184 }
185
BorderExpand(PyramidShort * pyr,int nlev,int mode)186 int PyramidShort::BorderExpand(PyramidShort *pyr, int nlev, int mode)
187 {
188 PyramidShort *tpyr = pyr + nlev - 1;
189 PyramidShort *scr = allocateImage(pyr[1].width, pyr[0].height, pyr->border);
190 if (scr == NULL) return 0;
191
192 if (mode > 0) {
193 // Expand and add (reconstruct from Laplacian)
194 for (; tpyr > pyr; tpyr--) {
195 scr->width = tpyr[0].width;
196 scr->height = tpyr[-1].height;
197 BorderExpandOdd(tpyr, tpyr - 1, scr, 1);
198 }
199 }
200 else if (mode < 0) {
201 // Expand and subtract (build Laplacian)
202 while ((pyr++) < tpyr) {
203 scr->width = pyr[0].width;
204 scr->height = pyr[-1].height;
205 BorderExpandOdd(pyr, pyr - 1, scr, -1);
206 }
207 }
208
209 freeImage(scr);
210 return 1;
211 }
212
BorderReduceOdd(PyramidShort * in,PyramidShort * out,PyramidShort * scr)213 void PyramidShort::BorderReduceOdd(PyramidShort *in, PyramidShort *out, PyramidShort *scr)
214 {
215 ImageTypeShortBase *s, *ns, *ls, *p, *np;
216
217 int off = scr->border - 2;
218 s = scr->ptr[-scr->border] - (off >> 1);
219 ns = s + scr->pitch;
220 ls = scr->ptr[scr->height + scr->border - 1] + scr->pitch - (off >> 1);
221 int width = scr->width + scr->border;
222 p = in->ptr[-scr->border] - off;
223 np = p + in->pitch;
224
225 // treat it as if the whole thing were the image
226 for (; s < ls; s = ns, ns += scr->pitch, p = np, np += in->pitch) {
227 for (int w = width; w--; s++, p += 2) {
228 *s = (short)((((int) p[-2]) + ((int) p[2]) + 8 + // 1
229 ((((int) p[-1]) + ((int) p[1])) << 2) + // 4
230 ((int) *p) * 6) >> 4); // 6
231 }
232 }
233
234 BorderSpread(scr, 5, 4 + ((in->width ^ 1) & 1), 0, 0); //
235
236 s = out->ptr[-(off >> 1)] - out->border;
237 ns = s + out->pitch;
238 ls = s + out->pitch * (out->height + off);
239 p = scr->ptr[-off] - out->border;
240 int pitch = scr->pitch;
241 int pitch2 = pitch << 1;
242 np = p + pitch2;
243 for (; s < ls; s = ns, ns += out->pitch, p = np, np += pitch2) {
244 for (int w = out->pitch; w--; s++, p++) {
245 *s = (short)((((int) p[-pitch2]) + ((int) p[pitch2]) + 8 + // 1
246 ((((int) p[-pitch]) + ((int) p[pitch])) << 2) + // 4
247 ((int) *p) * 6) >> 4); // 6
248 }
249 }
250 BorderSpread(out, 0, 0, 5, 5);
251
252 }
253
BorderReduce(PyramidShort * pyr,int nlev)254 int PyramidShort::BorderReduce(PyramidShort *pyr, int nlev)
255 {
256 PyramidShort *scr = allocateImage(pyr[1].width, pyr[0].height, pyr->border);
257 if (scr == NULL)
258 return 0;
259
260 BorderSpread(pyr, pyr->border, pyr->border, pyr->border, pyr->border);
261 while (--nlev) {
262 BorderReduceOdd(pyr, pyr + 1, scr);
263 pyr++;
264 scr->width = pyr[1].width;
265 scr->height = pyr[0].height;
266 }
267
268 freeImage(scr);
269 return 1;
270 }
271