Android -- 背景虚化
1，在项目中我们常有这样的需求，就是在个人中心的时候，当用户登录后，要显示用户登陆后的头像，然后背景是用户头像的虚化 ，接下来就来实现一下这个功能，先看一下效果
2，实现起来也挺简单的，没什么难度 ，不多说，直接上代码
contain_main.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/rl_content"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:layout_behavior="@string/appbar_scrolling_view_behavior"
tools:context="com.wangjitao.bluedemotest.MainActivity"
tools:showIn="@layout/activity_main">
<ImageView
android:id="@+id/imageview_ll"
android:layout_width="match_parent"
android:layout_height="300dp"
android:scaleType="fitXY"
/>
<ImageView
android:id="@+id/imageview"
android:layout_width="64dp"
android:layout_height="64dp"
android:layout_centerInParent="true"
/>
</RelativeLayout>
MainActivity.java
package com.wangjitao.bluedemotest;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.drawable.BitmapDrawable;
import android.os.Bundle;
import android.renderscript.Allocation;
import android.renderscript.RenderScript;
import android.renderscript.ScriptIntrinsicBlur;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.View;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.ImageView;
import android.widget.RelativeLayout;
import com.squareup.picasso.Picasso;
public class MainActivity extends AppCompatActivity {
private Context mContext = MainActivity.this;
private ImageView imageView ;
private ImageView imageview_ll ;
private RelativeLayout mRelativeLayout ;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
.setAction("Action", null).show();
}
});
initView();
}
private void initView() {
imageView = (ImageView) findViewById(R.id.imageview);
imageview_ll = (ImageView) findViewById(R.id.imageview_ll);
mRelativeLayout = (RelativeLayout) findViewById(R.id.rl_content);
Picasso.with(mContext)
.load(R.mipmap.img_feed_sakura)
.placeholder(R.drawable.img_circle_placeholder)
.resize(getResources().getDimensionPixelSize(R.dimen.global_menu_avatar_size),
getResources().getDimensionPixelSize(R.dimen.global_menu_avatar_size))
.centerCrop()
.transform(new CircleTransformation())
.into(imageView);
Bitmap bkg = BitmapFactory.decodeResource(getResources(), R.mipmap.img_feed_sakura);
imageview_ll.setImageBitmap(fastblur(bkg,10));
//blur(bkg,mRelativeLayout,20f);
}
private void blur(Bitmap bkg, View view, float radius) { //view.getMeasuredWidth() view.getMeasuredHeight()
Bitmap overlay = Bitmap.createBitmap(view.getMeasuredWidth(),view.getMeasuredHeight() , Bitmap.Config
.ARGB_8888);
Canvas canvas = new Canvas(overlay);
canvas.drawBitmap(bkg, -view.getLeft(), -view.getTop(), null);
RenderScript rs = RenderScript.create(this);
Allocation overlayAlloc = Allocation.createFromBitmap(rs, overlay);
ScriptIntrinsicBlur blur = ScriptIntrinsicBlur.create(rs, overlayAlloc.getElement());
blur.setInput(overlayAlloc);
blur.setRadius(radius);
blur.forEach(overlayAlloc);
overlayAlloc.copyTo(overlay);
view.setBackground(new BitmapDrawable(getResources(), overlay));
rs.destroy();
}
/*
* This method was copied from http://stackoverflow.com/a/10028267/694378.
* The only modifications I've made are to remove a couple of Log
* statements which could slow things down slightly.
*/
public Bitmap fastblur(Bitmap sentBitmap, int radius) {
// Stack Blur v1.0 from
// http://www.quasimondo.com/StackBlurForCanvas/StackBlurDemo.html
//
// Java Author: Mario Klingemann <mario at quasimondo.com>
// http://incubator.quasimondo.com
// created Feburary 29, 2004
// Android port : Yahel Bouaziz <yahel at kayenko.com>
// http://www.kayenko.com
// ported april 5th, 2012
// This is a compromise between Gaussian Blur and Box blur
// It creates much better looking blurs than Box Blur, but is
// 7x faster than my Gaussian Blur implementation.
//
// I called it Stack Blur because this describes best how this
// filter works internally: it creates a kind of moving stack
// of colors whilst scanning through the image. Thereby it
// just has to add one new block of color to the right side
// of the stack and remove the leftmost color. The remaining
// colors on the topmost layer of the stack are either added on
// or reduced by one, depending on if they are on the right or
// on the left side of the stack.
//
// If you are using this algorithm in your code please add
// the following line:
//
// Stack Blur Algorithm by Mario Klingemann <mario@quasimondo.com>
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];
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);
}
}
CircleTransformation.java
package com.wangjitao.bluedemotest;
import android.graphics.Bitmap;
import android.graphics.BitmapShader;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import com.squareup.picasso.Transformation;
public class CircleTransformation implements Transformation {
private static final int STROKE_WIDTH = 6;
@Override
public Bitmap transform(Bitmap source) {
int size = Math.min(source.getWidth(), source.getHeight());
int x = (source.getWidth() - size) / 2;
int y = (source.getHeight() - size) / 2;
Bitmap squaredBitmap = Bitmap.createBitmap(source, x, y, size, size);
if (squaredBitmap != source) {
source.recycle();
}
Bitmap bitmap = Bitmap.createBitmap(size, size, source.getConfig());
Canvas canvas = new Canvas(bitmap);
Paint avatarPaint = new Paint();
BitmapShader shader = new BitmapShader(squaredBitmap, BitmapShader.TileMode.CLAMP, BitmapShader.TileMode.CLAMP);
avatarPaint.setShader(shader);
Paint outlinePaint = new Paint();
outlinePaint.setColor(Color.WHITE);
outlinePaint.setStyle(Paint.Style.STROKE);
outlinePaint.setStrokeWidth(STROKE_WIDTH);
outlinePaint.setAntiAlias(true);
float r = size / 2f;
canvas.drawCircle(r, r, r, avatarPaint);
canvas.drawCircle(r, r, r - STROKE_WIDTH / 2, outlinePaint);
squaredBitmap.recycle();
return bitmap;
}
@Override
public String key() {
return "circleTransformation()";
}
}
