blurredImage

Widget genrateBluredImage() {
  return new Container(
    decoration: new BoxDecoration(
      image: new DecorationImage(
        image: new AssetImage('assets/horse.jpg'),
        fit: BoxFit.cover,
      ),
    ),
    //I blured the parent conainer to blur background image, you can get rid of this part
    child: BackdropFilter(
      filter: ImageFilter.blur(sigmaX: 9.0, sigmaY: 9.0),
      child: Container(
        //you can change opacity with color here(I used black) for background.
        decoration: new BoxDecoration(color: Colors.black.withOpacity(0.2)),
      ),
    ),
  );