1 package com.example.hairglassbackdemo;
2
3 import android.graphics.Bitmap;
4
5 public class FastBlur {
6 public static Bitmap doBlur(Bitmap sentBitmap, int radius, boolean canReuseInBitmap) {
7
8 // Stack Blur v1.0 from
9 // http://www.quasimondo.com/StackBlurForCanvas/StackBlurDemo.html
10 //
11 // Java Author: Mario Klingemann <mario at="" quasimondo.com="">
12 // http://incubator.quasimondo.com
13 // created Feburary 29, 2004
14 // Android port : Yahel Bouaziz <yahel at="" kayenko.com="">
15 // http://www.kayenko.com
16 // ported april 5th, 2012
17
18 // This is a compromise between Gaussian Blur and Box blur
19 // It creates much better looking blurs than Box Blur, but is
20 // 7x faster than my Gaussian Blur implementation.
21 //
22 // I called it Stack Blur because this describes best how this
23 // filter works internally: it creates a kind of moving stack
24 // of colors whilst scanning through the image. Thereby it
25 // just has to add one new block of color to the right side
26 // of the stack and remove the leftmost color. The remaining
27 // colors on the topmost layer of the stack are either added on
28 // or reduced by one, depending on if they are on the right or
29 // on the left side of the stack.
30 //
31 // If you are using this algorithm in your code please add
32 // the following line:
33 //
34 // Stack Blur Algorithm by Mario Klingemann <mario@quasimondo.com>
35
36 Bitmap bitmap;
37 if (canReuseInBitmap) {
38 bitmap = sentBitmap;
39 } else {
40 bitmap = sentBitmap.copy(sentBitmap.getConfig(), true);
41 }
42
43 if (radius < 1) {
44 return (null);
45 }
46
47 int w = bitmap.getWidth();
48 int h = bitmap.getHeight();
49
50 int[] pix = new int[w * h];
51 bitmap.getPixels(pix, 0, w, 0, 0, w, h);
52
53 int wm = w - 1;
54 int hm = h - 1;
55 int wh = w * h;
56 int div = radius + radius + 1;
57
58 int r[] = new int[wh];
59 int g[] = new int[wh];
60 int b[] = new int[wh];
61 int rsum, gsum, bsum, x, y, i, p, yp, yi, yw;
62 int vmin[] = new int[Math.max(w, h)];
63
64 int divsum = (div + 1) >> 1;
65 divsum *= divsum;
66 int dv[] = new int[256 * divsum];
67 for (i = 0; i < 256 * divsum; i++) {
68 dv[i] = (i / divsum);
69 }
70
71 yw = yi = 0;
72
73 int[][] stack = new int[div][3];
74 int stackpointer;
75 int stackstart;
76 int[] sir;
77 int rbs;
78 int r1 = radius + 1;
79 int routsum, goutsum, boutsum;
80 int rinsum, ginsum, binsum;
81
82 for (y = 0; y < h; y++) {
83 rinsum = ginsum = binsum = routsum = goutsum = boutsum = rsum = gsum = bsum = 0;
84 for (i = -radius; i <= radius; i++) {
85 p = pix[yi + Math.min(wm, Math.max(i, 0))];
86 sir = stack[i + radius];
87 sir[0] = (p & 0xff0000) >> 16;
88 sir[1] = (p & 0x00ff00) >> 8;
89 sir[2] = (p & 0x0000ff);
90 rbs = r1 - Math.abs(i);
91 rsum += sir[0] * rbs;
92 gsum += sir[1] * rbs;
93 bsum += sir[2] * rbs;
94 if (i > 0) {
95 rinsum += sir[0];
96 ginsum += sir[1];
97 binsum += sir[2];
98 } else {
99 routsum += sir[0];
100 goutsum += sir[1];
101 boutsum += sir[2];
102 }
103 }
104 stackpointer = radius;
105
106 for (x = 0; x < w; x++) {
107
108 r[yi] = dv[rsum];
109 g[yi] = dv[gsum];
110 b[yi] = dv[bsum];
111
112 rsum -= routsum;
113 gsum -= goutsum;
114 bsum -= boutsum;
115
116 stackstart = stackpointer - radius + div;
117 sir = stack[stackstart % div];
118
119 routsum -= sir[0];
120 goutsum -= sir[1];
121 boutsum -= sir[2];
122
123 if (y == 0) {
124 vmin[x] = Math.min(x + radius + 1, wm);
125 }
126 p = pix[yw + vmin[x]];
127
128 sir[0] = (p & 0xff0000) >> 16;
129 sir[1] = (p & 0x00ff00) >> 8;
130 sir[2] = (p & 0x0000ff);
131
132 rinsum += sir[0];
133 ginsum += sir[1];
134 binsum += sir[2];
135
136 rsum += rinsum;
137 gsum += ginsum;
138 bsum += binsum;
139
140 stackpointer = (stackpointer + 1) % div;
141 sir = stack[(stackpointer) % div];
142
143 routsum += sir[0];
144 goutsum += sir[1];
145 boutsum += sir[2];
146
147 rinsum -= sir[0];
148 ginsum -= sir[1];
149 binsum -= sir[2];
150
151 yi++;
152 }
153 yw += w;
154 }
155 for (x = 0; x < w; x++) {
156 rinsum = ginsum = binsum = routsum = goutsum = boutsum = rsum = gsum = bsum = 0;
157 yp = -radius * w;
158 for (i = -radius; i <= radius; i++) {
159 yi = Math.max(0, yp) + x;
160
161 sir = stack[i + radius];
162
163 sir[0] = r[yi];
164 sir[1] = g[yi];
165 sir[2] = b[yi];
166
167 rbs = r1 - Math.abs(i);
168
169 rsum += r[yi] * rbs;
170 gsum += g[yi] * rbs;
171 bsum += b[yi] * rbs;
172
173 if (i > 0) {
174 rinsum += sir[0];
175 ginsum += sir[1];
176 binsum += sir[2];
177 } else {
178 routsum += sir[0];
179 goutsum += sir[1];
180 boutsum += sir[2];
181 }
182
183 if (i < hm) {
184 yp += w;
185 }
186 }
187 yi = x;
188 stackpointer = radius;
189 for (y = 0; y < h; y++) {
190 // Preserve alpha channel: ( 0xff000000 & pix[yi] )
191 pix[yi] = (0xff000000 & pix[yi]) | (dv[rsum] << 16) | (dv[gsum] << 8) | dv[bsum];
192
193 rsum -= routsum;
194 gsum -= goutsum;
195 bsum -= boutsum;
196
197 stackstart = stackpointer - radius + div;
198 sir = stack[stackstart % div];
199
200 routsum -= sir[0];
201 goutsum -= sir[1];
202 boutsum -= sir[2];
203
204 if (x == 0) {
205 vmin[y] = Math.min(y + r1, hm) * w;
206 }
207 p = x + vmin[y];
208
209 sir[0] = r[p];
210 sir[1] = g[p];
211 sir[2] = b[p];
212
213 rinsum += sir[0];
214 ginsum += sir[1];
215 binsum += sir[2];
216
217 rsum += rinsum;
218 gsum += ginsum;
219 bsum += binsum;
220
221 stackpointer = (stackpointer + 1) % div;
222 sir = stack[stackpointer];
223
224 routsum += sir[0];
225 goutsum += sir[1];
226 boutsum += sir[2];
227
228 rinsum -= sir[0];
229 ginsum -= sir[1];
230 binsum -= sir[2];
231
232 yi += w;
233 }
234 }
235
236 bitmap.setPixels(pix, 0, w, 0, 0, w, h);
237
238 return (bitmap);
239 }
240 }
