upload Image to firebase storage and NOT File - flutter

Question

There are lot of references of uploading a dart:io 'File' but I want to upload a material.dart Image to firebase.
My Image comes from a processed Thumbnail of a video and not just picked by a Image picker.
This is how I generate a thumbnail,
Future<ThumbnailResult> genThumbnail(url) async {
//WidgetsFlutterBinding.ensureInitialized();
Uint8List bytes;
final Completer<ThumbnailResult> completer = Completer();
bytes = await VideoThumbnail.thumbnailData(
video: url,
imageFormat: ImageFormat.JPEG,
maxHeight: 250,
maxWidth: 300,
timeMs: 0,
quality: 0);
int _imageDataSize = bytes.length;
print("image size: $_imageDataSize");
final _image = Image.memory(bytes);
//final _file =File.fromRawPath(bytes);
_image.image
.resolve(ImageConfiguration())
.addListener(ImageStreamListener((ImageInfo info, bool _) {
completer.complete(ThumbnailResult(
image: _image,
dataSize: _imageDataSize,
height: info.image.height,
width: info.image.width,
));
}));
return completer.future;
}
and this is how File is uploaded to firebase
String Thumbfileurl = await uploadFile(thumbResult.image, fileName, fileType);
And inside uploadFile()
final StorageUploadTask uploadTask = storageReference.putFile(file);
So as you see , A File is needed , but i have an Image , is there a way to Convert Image to File or is there any workaround to achieve this .