Blur image in android using code

add in Build.gradle file : -

defaultConfig {
        renderscriptTargetApi 18
        renderscriptSupportModeEnabled true
    }

Add in Activity : -

ImageView imageView = (ImageView) findViewById(R.id.imageView);
Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.background);
        Bitmap blurredBitmap = blur(bitmap);
        imageView.setImageBitmap(blurredBitmap);

 public Bitmap blur(Bitmap image) {
        if (null == image)
            return null;

        Bitmap outputBitmap = Bitmap.createBitmap(image);
        final RenderScript renderScript = RenderScript.create(this);
        Allocation tmpIn = Allocation.createFromBitmap(renderScript, image);
        Allocation tmpOut = Allocation.createFromBitmap(renderScript, outputBitmap);

        //Intrinsic Gausian blur filter
        ScriptIntrinsicBlur theIntrinsic = null;
        if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.JELLY_BEAN_MR1) {
            theIntrinsic = ScriptIntrinsicBlur.create(renderScript, Element.U8_4(renderScript));
            theIntrinsic.setRadius(BLUR_RADIUS);
            theIntrinsic.setInput(tmpIn);
            theIntrinsic.forEach(tmpOut);
        }

        tmpOut.copyTo(outputBitmap);
        return outputBitmap;
    }