How do you display an Image with a FutureBuilder?

Question

I have an Image object from dart:ui. How can I display it in my app with a FutureBuilder?

import 'dart:ui' as ui;

...
Future<ui.Image> makeImage() async {
// Code for generating the Image.
}
...

Container(width: 600, height: 200, child: FutureBuilder<ui.Image>(
  future: makeImage(),
  builder: (BuildContext context, AsyncSnapshot<ui.Image> snapshot) {
    if (snapshot.hasData) {
      
      return Image.memory(?????????????);
    }
    else {
      return Text("waiting");
    }
  }),),