高斯模糊

原文地址：https://github.com/zuiwuyuan/FastBlur_VoiceChat

private int scaleRatio =5;

private int blurRadius =5;

private void initView() {

img  = findViewById(R.id.img);

Bitmap img_bg = BitmapFactory.decodeResource(getResources(),R.mipmap.touxiang);

Bitmap scaledBitmap = Bitmap.createScaledBitmap(img_bg,

img_bg.getWidth() /scaleRatio,

img_bg.getHeight() /scaleRatio,

false);

img_bg = GaoSiMoHu.doBlur(scaledBitmap,blurRadius,true);

img.setImageBitmap(img_bg);
｝

引用的类

public class GaoSiMoHu {

public static Bitmap doBlur(Bitmap sentBitmap,int radius,boolean canReuseInBitmap) {

Bitmap bitmap;

if (canReuseInBitmap) {

bitmap = sentBitmap;

}else {

bitmap = sentBitmap.copy(sentBitmap.getConfig(),true);

}

if (radius <1) {

return (null);

}

int w = bitmap.getWidth();

int h = bitmap.getHeight();

int[] pix =new int[w * h];

bitmap.getPixels(pix,0, w,0,0, w, h);

int wm = w -1;

int hm = h -1;

int wh = w * h;

int div = radius + radius +1;

int r[] =new int[wh];

int g[] =new int[wh];

int b[] =new int[wh];

int rsum, gsum, bsum, x, y, i, p, yp, yi, yw;

int vmin[] =new int[Math.max(w, h)];

int divsum = (div +1) >>1;

divsum *= divsum;

int dv[] =new int[256 * divsum];

for (i =0; i <256 * divsum; i++) {

dv[i] = (i / divsum);

}

yw = yi =0;

int[][] stack =new int[div][3];

int stackpointer;

int stackstart;

int[] sir;

int rbs;

int r1 = radius +1;

int routsum, goutsum, boutsum;

int rinsum, ginsum, binsum;

for (y =0; y < h; y++) {

rinsum = ginsum = binsum = routsum = goutsum = boutsum = rsum = gsum = bsum =0;

for (i = -radius; i <= radius; i++) {

p = pix[yi + Math.min(wm, Math.max(i,0))];

sir = stack[i + radius];

sir[0] = (p &0xff0000) >>16;

sir[1] = (p &0x00ff00) >>8;

sir[2] = (p &0x0000ff);

rbs = r1 - Math.abs(i);

rsum += sir[0] * rbs;

gsum += sir[1] * rbs;

bsum += sir[2] * rbs;

if (i >0) {

rinsum += sir[0];

ginsum += sir[1];

binsum += sir[2];

}else {

routsum += sir[0];

goutsum += sir[1];

boutsum += sir[2];

}

}

stackpointer = radius;

for (x =0; x < w; x++) {

r[yi] = dv[rsum];

g[yi] = dv[gsum];

b[yi] = dv[bsum];

rsum -= routsum;

gsum -= goutsum;

bsum -= boutsum;

stackstart = stackpointer - radius + div;

sir = stack[stackstart % div];

routsum -= sir[0];

goutsum -= sir[1];

boutsum -= sir[2];

if (y ==0) {

vmin[x] = Math.min(x + radius +1, wm);

}

p = pix[yw + vmin[x]];

sir[0] = (p &0xff0000) >>16;

sir[1] = (p &0x00ff00) >>8;

sir[2] = (p &0x0000ff);

rinsum += sir[0];

ginsum += sir[1];

binsum += sir[2];

rsum += rinsum;

gsum += ginsum;

bsum += binsum;

stackpointer = (stackpointer +1) % div;

sir = stack[(stackpointer) % div];

routsum += sir[0];

goutsum += sir[1];

boutsum += sir[2];

rinsum -= sir[0];

ginsum -= sir[1];

binsum -= sir[2];

yi++;

}

yw += w;

}

for (x =0; x < w; x++) {

rinsum = ginsum = binsum = routsum = goutsum = boutsum = rsum = gsum = bsum =0;

yp = -radius * w;

for (i = -radius; i <= radius; i++) {

yi = Math.max(0, yp) + x;

sir = stack[i + radius];

sir[0] = r[yi];

sir[1] = g[yi];

sir[2] = b[yi];

rbs = r1 - Math.abs(i);

rsum += r[yi] * rbs;

gsum += g[yi] * rbs;

bsum += b[yi] * rbs;

if (i >0) {

rinsum += sir[0];

ginsum += sir[1];

binsum += sir[2];

}else {

routsum += sir[0];

goutsum += sir[1];

boutsum += sir[2];

}

if (i < hm) {

yp += w;

}

}

yi = x;

stackpointer = radius;

for (y =0; y < h; y++) {

// Preserve alpha channel: ( 0xff000000 & pix[yi] )

                pix[yi] = (0xff000000 & pix[yi]) | (dv[rsum] <<16) | (dv[gsum] <<8) | dv[bsum];

rsum -= routsum;

gsum -= goutsum;

bsum -= boutsum;

stackstart = stackpointer - radius + div;

sir = stack[stackstart % div];

routsum -= sir[0];

goutsum -= sir[1];

boutsum -= sir[2];

if (x ==0) {

vmin[y] = Math.min(y + r1, hm) * w;

}

p = x + vmin[y];

sir[0] = r[p];

sir[1] = g[p];

sir[2] = b[p];

rinsum += sir[0];

ginsum += sir[1];

binsum += sir[2];

rsum += rinsum;

gsum += ginsum;

bsum += binsum;

stackpointer = (stackpointer +1) % div;

sir = stack[stackpointer];

routsum += sir[0];

goutsum += sir[1];

boutsum += sir[2];

rinsum -= sir[0];

ginsum -= sir[1];

binsum -= sir[2];

yi += w;

}

}

bitmap.setPixels(pix,0, w,0,0, w, h);

return (bitmap);

}

}