[java] How to blur background images in Android

What is the best way to blur background images like the image below? I saw some code and libraries but their are a couple of years old or like BlurBehind library, but it doesn't give the same effect. Thanks in advance!

You can quickly get to blur effect by doing the following.

// Add this to build.gradle app //

Compile ' com.github.jgabrielfreitas:BlurImageView:1.0.1 '

// Add to XML

<com.jgbrielfreitas.core.BlurImageView
    android:id="@+id/iv_blur_image"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
/>

//Add this to java

Import com.jgabrielfreitas.core.BlueImageView;

// Under public class *activity name * //

BlurImageView myBlurImage;

// Under Oncreate//

myBlurImage = (ImageView) findViewById(R.id.iv_blur_image)
MyBlurImage.setBlue(5)

I hope that helps someone

The simplest way to achieve this is given below,

I)

Glide.with(context.getApplicationContext())
                        .load(Your Path)   
                        .override(15, 15) // (change according to your wish)
                        .error(R.drawable.placeholder)
                        .into(image.score);

else you can follow the code below..

II)

1.Create a class.(Code is given below)

public class BlurTransformation extends BitmapTransformation {

    private RenderScript rs;

    public BlurTransformation(Context context) {
        super( context );

        rs = RenderScript.create( context );
    }

    @Override
    protected Bitmap transform(BitmapPool pool, Bitmap toTransform, int outWidth, int outHeight) {
        Bitmap blurredBitmap = toTransform.copy( Bitmap.Config.ARGB_8888, true );

        // Allocate memory for Renderscript to work with
        Allocation input = Allocation.createFromBitmap(
            rs, 
            blurredBitmap, 
            Allocation.MipmapControl.MIPMAP_FULL, 
            Allocation.USAGE_SHARED
        );
        Allocation output = Allocation.createTyped(rs, input.getType());

        // Load up an instance of the specific script that we want to use.
        ScriptIntrinsicBlur script = ScriptIntrinsicBlur.create(rs, Element.U8_4(rs));
        script.setInput(input);

        // Set the blur radius
        script.setRadius(10);

        // Start the ScriptIntrinisicBlur
        script.forEach(output);

        // Copy the output to the blurred bitmap
        output.copyTo(blurredBitmap);

        toTransform.recycle();

        return blurredBitmap;
    }

    @Override
    public String getId() {
        return "blur";
    }
}

2.Set image to ImageView using Glide.

eg:

Glide.with(this)
     .load(expertViewDetailsModel.expert.image)
     .asBitmap()
     .transform(new BlurTransformation(this))
     .into(ivBackground);

You can use

    Glide.with(getContext()).load(R.mipmap.bg)
            .apply(bitmapTransform(new BlurTransformation(22)))
            .into((ImageView) view.findViewById(R.id.imBg));

this might not be the most efficient solution but I had to use it since the wasabeef/Blurry library didn't work for me. this could be handy if you intend to have some getting-blurry animation:

1- you need to have 2 versions of the picture, normal one and the blurry one u make with photoshop or whatever

2- set the images fit on each other in your xml, then one of them could be seen and that's the upper one

3- set fadeout animation on the upper one:

final Animation fadeOut = new AlphaAnimation(1, 0);
        fadeOut.setInterpolator(new AccelerateInterpolator());
        fadeOut.setDuration(1000);


        fadeOut.setAnimationListener(new Animation.AnimationListener() {
            @Override
            public void onAnimationStart(Animation animation) {}

            @Override
            public void onAnimationEnd(Animation animation) {upperone.setVisibility(View.GONE);}

            @Override
            public void onAnimationRepeat(Animation animation) {}
        });

        upperone.startAnimation(fadeOut);

This might be a very late reply but I hope it helps someone.

1. You can use third party libs such as RenderScript/Blurry/etc.
2. If you do not want to use any third party libs, you can do the below using alpha(setting alpha to 0 means complete blur and 1 means same as existing).

Note(If you are using point 2) : While setting alpha to the background, it will blur the whole layout. To avoid this, create a new xml containing drawable and set alpha here to 0.5 (or value of your wish) and use this drawable name (name of file) as the background.

For example, use it as below (say file name is bgndblur.xml):

<bitmap xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:shape="rectangle"
android:src="@drawable/registerscreenbackground" 
android:alpha="0.5">

Use the below in your layout :

<....
 android:background="@drawable/bgndblur">

Hope this helped.

Try below code.. Put This Code in On Create..

 if (android.os.Build.VERSION.SDK_INT > 9) {
            StrictMode.ThreadPolicy policy =
                    new StrictMode.ThreadPolicy.Builder().permitAll().build();
            StrictMode.setThreadPolicy(policy);
        }
       Url="https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcTIur0ueOsmVmFVmAA-SxcCT7bTodZb3eCNbiShIiP9qWCWk3mDfw";
//        Picasso.with(getContext()).load(Url).into(img_profile);
//        Picasso.with(getContext()).load(Url).into(img_c_profile);

        bitmap=getBitmapFromURL(Url);
        Bitmap blurred = blurRenderScript(bitmap, 12);//second parametre is radius
        img_profile.setImageBitmap(blurred);

Create Below Methods.. Just Copy Past..

 public static Bitmap getBitmapFromURL(String src) {
        try {
            URL url = new URL(src);
            HttpURLConnection connection = (HttpURLConnection) url.openConnection();
            connection.setDoInput(true);
            connection.connect();
            InputStream input = connection.getInputStream();
            Bitmap myBitmap = BitmapFactory.decodeStream(input);
            return myBitmap;
        } catch (IOException e) {
            // Log exception
            return null;
        }
    }
    @SuppressLint("NewApi")
    private Bitmap blurRenderScript(Bitmap smallBitmap, int radius) {

        try {
            smallBitmap = RGB565toARGB888(smallBitmap);
        } catch (Exception e) {
            e.printStackTrace();
        }


        Bitmap bitmap = Bitmap.createBitmap(
                smallBitmap.getWidth(), smallBitmap.getHeight(),
                Bitmap.Config.ARGB_8888);

        RenderScript renderScript = RenderScript.create(getActivity());

        Allocation blurInput = Allocation.createFromBitmap(renderScript, smallBitmap);
        Allocation blurOutput = Allocation.createFromBitmap(renderScript, bitmap);

        ScriptIntrinsicBlur blur = ScriptIntrinsicBlur.create(renderScript,
                Element.U8_4(renderScript));
        blur.setInput(blurInput);
        blur.setRadius(radius); // radius must be 0 < r <= 25
        blur.forEach(blurOutput);

        blurOutput.copyTo(bitmap);
        renderScript.destroy();

        return bitmap;

    }

    private Bitmap RGB565toARGB888(Bitmap img) throws Exception {
        int numPixels = img.getWidth() * img.getHeight();
        int[] pixels = new int[numPixels];

        //Get JPEG pixels.  Each int is the color values for one pixel.
        img.getPixels(pixels, 0, img.getWidth(), 0, 0, img.getWidth(), img.getHeight());

        //Create a Bitmap of the appropriate format.
        Bitmap result = Bitmap.createBitmap(img.getWidth(), img.getHeight(), Bitmap.Config.ARGB_8888);

        //Set RGB pixels.
        result.setPixels(pixels, 0, result.getWidth(), 0, 0, result.getWidth(), result.getHeight());
        return result;
    }

you can use Glide for load and transform into blur image, 1) for only one view,

val requestOptions = RequestOptions()
                requestOptions.transform(BlurTransformation(50)) // 0-100
Glide.with(applicationContext).setDefaultRequestOptions(requestOptions)
                        .load(imageUrl).into(view)

2) if you are using the adapter to load an image in the item, you should write your code in the if-else block, otherwise, it will make all your images blurry.

 if(isBlure){
  val requestOptions = RequestOptions()
                requestOptions.transform(BlurTransformation(50))
                Glide.with(applicationContext).setDefaultRequestOptions(requestOptions)
                        .load(imageUrl).into(view )
}else{
 val requestOptions = RequestOptions()
            Glide.with(applicationContext).setDefaultRequestOptions(requestOptions).load(imageUrl).into(view)
}

This is an easy way to blur Images Efficiently with Android's RenderScript that I found on this article

1. Create a Class called BlurBuilder

   public class BlurBuilder {
     private static final float BITMAP_SCALE = 0.4f;
     private static final float BLUR_RADIUS = 7.5f;
   
     public static Bitmap blur(Context context, Bitmap image) {
       int width = Math.round(image.getWidth() * BITMAP_SCALE);
       int height = Math.round(image.getHeight() * BITMAP_SCALE);
   
       Bitmap inputBitmap = Bitmap.createScaledBitmap(image, width, height, false);
       Bitmap outputBitmap = Bitmap.createBitmap(inputBitmap);
   
       RenderScript rs = RenderScript.create(context);
       ScriptIntrinsicBlur theIntrinsic = ScriptIntrinsicBlur.create(rs, Element.U8_4(rs));
       Allocation tmpIn = Allocation.createFromBitmap(rs, inputBitmap);
       Allocation tmpOut = Allocation.createFromBitmap(rs, outputBitmap);
       theIntrinsic.setRadius(BLUR_RADIUS);
       theIntrinsic.setInput(tmpIn);
       theIntrinsic.forEach(tmpOut);
       tmpOut.copyTo(outputBitmap);
   
       return outputBitmap;
     }
   }
   

2. Copy any image to your drawable folder

3. Use BlurBuilder in your activity like this:

   @Override
   protected void onCreate(Bundle savedInstanceState) {
       super.onCreate(savedInstanceState);
       requestWindowFeature(Window.FEATURE_NO_TITLE);
       getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
               WindowManager.LayoutParams.FLAG_FULLSCREEN);
       setContentView(R.layout.activity_login);
   
       mContainerView = (LinearLayout) findViewById(R.id.container);
       Bitmap originalBitmap = BitmapFactory.decodeResource(getResources(), R.drawable.background);
       Bitmap blurredBitmap = BlurBuilder.blur( this, originalBitmap );
       mContainerView.setBackground(new BitmapDrawable(getResources(), blurredBitmap));
   

4. Renderscript is included into support v8 enabling this answer down to api 8. To enable it using gradle include these lines into your gradle file (from this answer)

   defaultConfig {
       ...
       renderscriptTargetApi *your target api*
       renderscriptSupportModeEnabled true
   }
   

5. Result

You can have a view with Background color as black and set alpha for the view as 0.7 or whatever as per your requirement.

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@drawable/onboardingimg1">
    <View
        android:id="@+id/opacityFilter"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="@android:color/black"
        android:layout_alignParentBottom="true"
        android:alpha="0.7">
    </View>


</RelativeLayout>