borderradius

children: <Widget>[
                      new Container(
                        padding: new EdgeInsets.only(
                          left: 6.0,
                          right: 10.0,
                          top: 5.0,
                          bottom: 5.0,
                          ),
                        child:
                          new Container(
                            decoration: new BoxDecoration(
                              borderRadius: new BorderRadius.all(
                                const Radius.circular(80.0),
                              ),
                              color: Colors.red,
                            ),
                            child:
                            new Image.asset(
                            'images/lake.jpg',
                            height: 160.0,
                            fit: BoxFit.cover,
                            ),

                          ),
                      ),