一行java代码实现高斯模糊效果

package com.testdemo.blur_image_lib10;  import android.graphics.Bitmap; import android.graphics.BitmapFactory;   import java.io.BufferedInputStream; import java.io.BufferedOutputStream; import java.io.ByteArrayOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.net.URL;   /**  * Created by qcl on 14/7/15.  */ public class FastBlurUtil {  /**   * 根据imagepath获取bitmap   */  /**   * 得到本地或者网络上的bitmap url - 网络或者本地图片的绝对路径,比如:   * <p>   * A.网络路径: url="http://blog.foreverlove.us/girl2.png" ;   * <p>   * B.本地路径:url="file://mnt/sdcard/photo/image.png";   * <p>   * C.支持的图片格式 ,png, jpg,bmp,gif等等   *   * @param url   * @return   */  public static int IO_BUFFER_SIZE = 2 * 1024;  public static Bitmap GetUrlBitmap(String url, int scaleRatio) {   int blurRadius = 8;//通常设置为8就行。   if (scaleRatio <= 0) {    scaleRatio = 10;   }    Bitmap originBitmap = null;   InputStream in = null;   BufferedOutputStream out = null;   try {    in = new BufferedInputStream(new URL(url).openStream(), IO_BUFFER_SIZE);    final ByteArrayOutputStream dataStream = new ByteArrayOutputStream();    out = new BufferedOutputStream(dataStream, IO_BUFFER_SIZE);    copy(in, out);    out.flush();    byte[] data = dataStream.toByteArray();    originBitmap = BitmapFactory.decodeByteArray(data, 0, data.length);      Bitmap scaledBitmap = Bitmap.createScaledBitmap(originBitmap,      originBitmap.getWidth() / scaleRatio,      originBitmap.getHeight() / scaleRatio,      false);    Bitmap blurBitmap = doBlur(scaledBitmap, blurRadius, true);    return blurBitmap;   } catch (IOException e) {    e.printStackTrace();    return null;   }  }   private static void copy(InputStream in, OutputStream out)    throws IOException {   byte[] b = new byte[IO_BUFFER_SIZE];   int read;   while ((read = in.read(b)) != -1) {    out.write(b, 0, read);   }  }   // 把本地图片毛玻璃化  public static Bitmap toBlur(Bitmap originBitmap, int scaleRatio) {   //  int scaleRatio = 10;   // 增大scaleRatio缩放比，使用一样更小的bitmap去虚化可以到更好的得模糊效果，而且有利于占用内存的减小；   int blurRadius = 8;//通常设置为8就行。   //增大blurRadius，可以得到更高程度的虚化，不过会导致CPU更加intensive     /* 其中前三个参数很明显，其中宽高我们可以选择为原图尺寸的1/10；   第四个filter是指缩放的效果，filter为true则会得到一个边缘平滑的bitmap，   反之，则会得到边缘锯齿、pixelrelated的bitmap。   这里我们要对缩放的图片进行虚化，所以无所谓边缘效果，filter=false。*/   if (scaleRatio <= 0) {    scaleRatio = 10;   }   Bitmap scaledBitmap = Bitmap.createScaledBitmap(originBitmap,     originBitmap.getWidth() / scaleRatio,     originBitmap.getHeight() / scaleRatio,     false);   Bitmap blurBitmap = doBlur(scaledBitmap, blurRadius, true);   return blurBitmap;  }    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);  }   } 

package com.testdemo;   import android.app.Activity;  import android.content.res.Resources;  import android.graphics.Bitmap;  import android.graphics.BitmapFactory;  import android.os.Bundle;  import android.text.TextUtils;  import android.view.View;  import android.widget.EditText;  import android.widget.ImageView;   import com.testdemo.blur_image_lib10.FastBlurUtil;   public class MainActivity10_BlurImage extends Activity {   ImageView image;   EditText edit;    @Override   protected void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(R.layout.activity_main10_blur_image);    image = (ImageView) findViewById(R.id.image);    edit = (EditText) findViewById(R.id.edit);      findViewById(R.id.button2).setOnClickListener(new View.OnClickListener() {     @Override     public void onClick(View v) {      String pattern = edit.getText().toString();      int scaleRatio = 0;      if (TextUtils.isEmpty(pattern)) {       scaleRatio = 0;      } else if (scaleRatio < 0) {       scaleRatio = 10;      } else {       scaleRatio = Integer.parseInt(pattern);      }       //  获取需要被模糊的原图bitmap      Resources res = getResources();      Bitmap scaledBitmap = BitmapFactory.decodeResource(res, R.drawable.filter);       //  scaledBitmap为目标图像，10是缩放的倍数（越大模糊效果越高）      Bitmap blurBitmap = FastBlurUtil.toBlur(scaledBitmap, scaleRatio);      image.setScaleType(ImageView.ScaleType.CENTER_CROP);      image.setImageBitmap(blurBitmap);     }    });     findViewById(R.id.button).setOnClickListener(new View.OnClickListener() {     @Override     public void onClick(View v) {      //url为网络图片的url，10 是缩放的倍数（越大模糊效果越高）      final String pattern = edit.getText().toString();       final String url =        //  "http://imgs.duwu.me/duwu/doc/cover/201601/18/173040803962.jpg";        "http://b.hiphotos.baidu.com/album/pic/item/caef76094b36acafe72d0e667cd98d1000e99c5f.jpg?psign=e72d0e667cd98d1001e93901213fb80e7aec54e737d1b867";      new Thread(new Runnable() {       @Override       public void run() {        int scaleRatio = 0;        if (TextUtils.isEmpty(pattern)) {         scaleRatio = 0;        } else if (scaleRatio < 0) {         scaleRatio = 10;        } else {         scaleRatio = Integer.parseInt(pattern);        }  //      下面的这个方法必须在子线程中执行        final Bitmap blurBitmap2 = FastBlurUtil.GetUrlBitmap(url, scaleRatio);          //      刷新ui必须在主线程中执行         APP.runOnUIThread(new Runnable() {//这个是我自己封装的在主线程中刷新ui的方法。         @Override         public void run() {          image.setScaleType(ImageView.ScaleType.CENTER_CROP);          image.setImageBitmap(blurBitmap2);          }        });       }      }).start();       }    });     }   }  

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"  xmlns:tools="http://schemas.android.com/tools"  android:layout_width="match_parent"  android:layout_height="match_parent"  android:orientation="vertical">   <ImageView android:id="@+id/image2" android:layout_width="match_parent" android:layout_height="220dp" android:background="@drawable/filter"/>   <LinearLayout android:layout_width="match_parent" android:layout_height="wrap_content" android:orientation="horizontal">   <EditText android:id="@+id/edit" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginTop="15dp" android:hint="输入模糊度" />   <Button android:id="@+id/button2" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="转化毛玻璃"/>   <Button android:id="@+id/button" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginLeft="4dp" android:text="转化网络图片毛玻璃"/> </LinearLayout>   <ImageView android:id="@+id/image" android:layout_width="match_parent" android:layout_height="220dp" android:layout_below="@+id/image2" /> </LinearLayout>