Flutter can I print images on a USB printer with the quick_usb package?

Question

I am making an app that prints PDFs or images using a USB printer.
If you load an image of an asset and print it with a USB printer, text is printed, not the image.

Asset image loading method

Uint8List? imageData;

void loadAsset() async {
    Uint8List data = (await rootBundle.load('assets/images/1-1.JPG'))
        .buffer
        .asUint8List();
    setState(() => this.imageData = data);
  }

Initialize with the init button

 Widget _init_exit() {
    return Row(
      mainAxisAlignment: MainAxisAlignment.spaceEvenly,
      children: [
        RaisedButton(
          child: Text('init'),
          onPressed: () async {
            var init = await QuickUsb.init();
            loadAsset();
            log('init $init');
          },
        ),
        RaisedButton(
          child: Text('exit'),
          onPressed: () async {
            await QuickUsb.exit();
            log('exit');
          },
        ),
      ],
    );
  }

Grant the permission of the connected device.

    return Row(
      mainAxisAlignment: MainAxisAlignment.spaceEvenly,
      children: [
        RaisedButton(
          child: Text('hasPermission'),
          onPressed: () async {
            var hasPermission = await QuickUsb.hasPermission(_deviceList!.first);
            log('hasPermission $hasPermission');
          },
        ),
        RaisedButton(
          child: Text('requestPermission'),
          onPressed: () async {
            await QuickUsb.requestPermission(_deviceList!.first);
            log('requestPermission');
          },
        ),
      ],
    );
  }

Now we do input/output. Output the imageData from which the image of the asset was loaded.

 Widget _bulk_transfer(){

    return Row(
      mainAxisAlignment: MainAxisAlignment.spaceEvenly,
      children: [
        RaisedButton(
          child: Text('bulkTransferIn'),
          onPressed: () async {
            var endpoint = _configuration!.interfaces[0].endpoints
                .firstWhere((e) => e.direction == UsbEndpoint.DIRECTION_IN);
            var bulkTransferIn = await QuickUsb.bulkTransferIn(endpoint, 2048);
            log('bulkTransferIn ${hex.encode(bulkTransferIn)}');
          },
        ),
        RaisedButton(
          child: Text('bulkTransferOut'),
          onPressed: () async {

            var data = Uint8List.fromList(imageData!);
            var endpoint = _configuration!.interfaces[0].endpoints
                .firstWhere((e) => e.direction == UsbEndpoint.DIRECTION_OUT);
            var bulkTransferOut =
            await QuickUsb.bulkTransferOut(endpoint, data);
            log('bulkTransferOut $bulkTransferOut');
          },
        ),
      ],
    );
  }

However, it is output as text, not as an image. I want to output an image, not text.

If you know of any trivial advice or hints, please let me know.