Create blur edge on bitmap, using BlurMaskFilter.

The android.graphics.BlurMaskFilter class takes a mask, and blurs its edge by the specified radius. This example show how to make blur bitmap inner, and blur white outer edge.

package com.AndroidBitmapProcessing;

import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.BlurMaskFilter;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.SeekBar;
import android.widget.SeekBar.OnSeekBarChangeListener;
import android.widget.TextView;

public class AndroidBitmapProcessingActivity extends Activity {
 
 ImageView imageView_Source, imageAfter;
 Bitmap bitmap_Source, bitmap_Dest;
 
 SeekBar blurBar;
 TextView blurText;
 Button doProcess;
 
 int blurValue = 1;
 
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        imageView_Source = (ImageView)findViewById(R.id.source);
        imageAfter = (ImageView)findViewById(R.id.imageAfter);

        //bitmap_Source = BitmapFactory.decodeResource(getResources(), R.drawable.testpicture);
        bitmap_Source = BitmapFactory.decodeResource(getResources(), R.drawable.ic_launcher);
        imageAfter.setImageBitmap(processingBitmap_Blur(bitmap_Source));
        
        blurBar = (SeekBar)findViewById(R.id.blurBar);
        blurText = (TextView)findViewById(R.id.blurText);
        doProcess = (Button)findViewById(R.id.doProcess);
        
        blurBar.setOnSeekBarChangeListener(blurBarChangeListener);
        doProcess.setOnClickListener(doProcessClickListener);
        
    }
    
    OnClickListener doProcessClickListener
    = new OnClickListener(){

  @Override
  public void onClick(View v) {
   // TODO Auto-generated method stub
   imageAfter.setImageBitmap(processingBitmap_Blur(bitmap_Source));
  }};
    
    OnSeekBarChangeListener blurBarChangeListener
    = new OnSeekBarChangeListener(){

  @Override
  public void onProgressChanged(SeekBar seekBar, int progress,
    boolean fromUser) {
   blurValue = progress+1;
   blurText.setText(String.valueOf(blurValue));
  }

  @Override
  public void onStartTrackingTouch(SeekBar seekBar) {
   // TODO Auto-generated method stub
   
  }

  @Override
  public void onStopTrackingTouch(SeekBar seekBar) {
   // TODO Auto-generated method stub
   
  }
     
    };

    private Bitmap processingBitmap_Blur(Bitmap src){
     int width = src.getWidth();
        int height = src.getHeight();
        
     BlurMaskFilter blurMaskFilter;
     Paint paintBlur = new Paint();
     
     Bitmap dest = Bitmap.createBitmap(width, height, Bitmap.Config.RGB_565);
     Canvas canvas = new Canvas(dest); 
     
     //Create background in White
     Bitmap alpha = src.extractAlpha();
     paintBlur.setColor(0xFFFFFFFF);
     canvas.drawBitmap(alpha, 0, 0, paintBlur);
     
     //Create outer blur, in White
     blurMaskFilter = new BlurMaskFilter(blurValue, BlurMaskFilter.Blur.OUTER);
     paintBlur.setMaskFilter(blurMaskFilter);
     canvas.drawBitmap(alpha, 0, 0, paintBlur);
     
     //Create inner blur
     blurMaskFilter = new BlurMaskFilter(blurValue, BlurMaskFilter.Blur.INNER);
     paintBlur.setMaskFilter(blurMaskFilter);
     canvas.drawBitmap(src, 0, 0, paintBlur);
     
     
     
     return dest;
    }

}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >

    <TextView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="@string/hello" />
    <ScrollView 
        android:layout_width="fill_parent"
        android:layout_height="fill_parent">
        <LinearLayout 
            android:layout_width="fill_parent"
         android:layout_height="fill_parent"
         android:orientation="vertical" >
         <TextView
             android:layout_width="fill_parent"
             android:layout_height="wrap_content"
             android:text="Original" />
      <ImageView
          android:id="@+id/source" 
          android:layout_width="wrap_content"
          android:layout_height="wrap_content" 
          android:src="@drawable/ic_launcher"/>
      <TextView
             android:layout_width="fill_parent"
             android:layout_height="wrap_content"
             android:text="Result" />
      <ImageView
          android:id="@+id/imageAfter" 
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"/>
   <SeekBar
       android:id="@+id/blurBar"
       android:layout_width="fill_parent"
       android:layout_height="wrap_content"
       android:max="99"
       android:progress="0"/>
   <TextView
       android:id="@+id/blurText"
       android:layout_width="fill_parent"
       android:layout_height="wrap_content"
       android:text="1"/>
   <Button
       android:id="@+id/doProcess"
       android:layout_width="fill_parent"
       android:layout_height="wrap_content"
       android:text="Do Process"/>
     </LinearLayout>
 </ScrollView>
</LinearLayout>

Tweet