android 图像模糊处理

public Bitmap fastblur(Bitmap sentBitmap, int radius) {

  Bitmap 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];

  Log.e("pix", w + " " + h + " " + pix.length);

  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;

   }

  }

  Log.e("pix", w + " " + h + " " + pix.length);

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

  return (bitmap);

 }