高斯模糊

高斯模糊的使用

import android.annotation.SuppressLint;
import android.content.Context;
import android.graphics.Bitmap;
import android.os.Build.VERSION;
import android.renderscript.Allocation;
import android.renderscript.Element;
import android.renderscript.RenderScript;
import android.renderscript.ScriptIntrinsicBlur;
import android.util.Log;


public class Blur {


private static final String TAG = "Blur";


@SuppressLint("NewApi")
public static Bitmap fastblur(Context context, Bitmap sentBitmap, int radius) {


if (VERSION.SDK_INT > 20) {
Bitmap bitmap = sentBitmap.copy(sentBitmap.getConfig(), true);


final RenderScript rs = RenderScript.create(context);
final Allocation input = Allocation.createFromBitmap(rs, sentBitmap, Allocation.MipmapControl.MIPMAP_NONE,
Allocation.USAGE_SCRIPT);
final Allocation output = Allocation.createTyped(rs, input.getType());
final ScriptIntrinsicBlur script = ScriptIntrinsicBlur.create(rs, Element.U8_4(rs));
script.setRadius(radius /* e.g. 3.f */);
script.setInput(input);
script.forEach(output);
output.copyTo(bitmap);
return bitmap;
}


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);
}


}


使用如下，直接调用setPanelBg()方法。




private void loadRecentBg() {
mDisplay.getRealMetrics(mDisplayMetrics);
if(null != mPanelBg && !mPanelBg.isRecycled()){
mPanelBg.recycle();
}
try{
Bitmap ScreenBitmap = GnSurface.screenshot((mDisplayMetrics.widthPixels>>2), (mDisplayMetrics.heightPixels>>2));//截屏
mPanelBg = Blur.fastblur(mContext, ScreenBitmap, 20);//高斯模糊
if (!ScreenBitmap.isRecycled()){
ScreenBitmap.recycle();
}
}catch(Exception e){

}
    }
private static Bitmap small(Bitmap bitmap) {
Matrix matrix = new Matrix();
matrix.postScale(0.2f, 0.2f);
Bitmap resizeBmp = Bitmap.createBitmap(bitmap, 0, 0, bitmap.getWidth(),
bitmap.getHeight(), matrix, true);
return resizeBmp;
}
public void setPanelBg(){
if(null == mPanelBg){
loadRecentBg();
}
if(null != mBackgroundImg){
mBackgroundImg.setImageBitmap(mPanelBg);
}
}