Android Background Blur

BitmapUtils.java

public static Bitmap getBitmapFromView(View view) {
    Bitmap bitmap = Bitmap.createBitmap(view.getWidth(), view.getHeight(), Bitmap.Config.ARGB_8888);
    Canvas c = new Canvas(bitmap);
    view.layout(view.getLeft(), view.getTop(), view.getRight(), view.getBottom());
    view.draw(c);
    return bitamp;
}

RSBlurProcessor.java

public class RSBlurProcessor {

    private RenderScript rs;
    
    private static final boolean IS_BLUR_SUPPORTED = Build.VERSION.SDK_INT >= 17;
    private static final int MAX_RADIUS = 25;

    public RSBlurProcessor(RenderScript rs) {
        this.rs = rs;
    }

    @Nullable
    public Bitmap blur(@NonNull Bitmap bitmap, float radius, int repeat) {

        if (!IS_BLUR_SUPPORTED) {
            return null;
        }

        if (radius > MAX_RADIUS) {
            radius = MAX_RADIUS;
        }

        int width = bitmap.getWidth();
        int height = bitmap.getHeight();
        
        // Create allocation type
        Type bitmapType = new Type.Builder(rs, Element.RGBA_8888(rs))
                .setX(width)
                .setY(height)
                .setMipmaps(false) // We are using MipmapControl.MIPMAP_NONE
                .create();
        
        // Create allocation
        Allocation allocation = Allocation.createTyped(rs, bitmapType);
        
        // Create blur script
        ScriptIntrinsicBlur blurScript = ScriptIntrinsicBlur.create(rs, Element.U8_4(rs));
        blurScript.setRadius(radius);
      
        // Copy data to allocation
        allocation.copyFrom(bitmap);
        
        // set blur script input
        blurScript.setInput(allocation);
        
        // invoke the script to blur
        blurScript.forEach(allocation);
        
        // Repeat the blur for extra effect
        for (int i=0; i<repeat; i++) {
            blurScript.forEach(allocation);
        }
        
        // copy data back to the bitmap
        allocation.copyTo(bitmap);
        
        // release memory
        allocation.destroy();
        blurScript.destroy();
        allocation = null;
        blurScript = null;

        return bitmap;
    }
}

@core2root

RenderScript renderScript = RenderScript.create(context);
new RSBlurProcessor(renderScript).blur(getBitmapFromView(mView), 15, 1);

view.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
@OverRide
public void onGlobalLayout() {
view.getViewTreeObserver().removeOnGlobalLayoutListener(this);
getBitmapFromView(view);
}
});