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: 
  * 
 
  * A.网络路径: url="http://blog.foreverlove.us/girl2.png" ; 
  * 
 
  * B.本地路径:url="file://mnt/sdcard/photo/image.png"; 
  * 
 
  * 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(); 
 
 
    } 
   }); 
 
 
  } 
 
 }