Is it possible at the moment to resize an image without "locking up" the Flutter app UI?

I am using the image_picker plugin to pick an image from the device's Photo Gallery and image.dart lib https://pub.dartlang.org/packages/image to resize the chosen image to a more manageable resolution and then upload it to Firebase Cloud Storage. While the image decoded and then encoded the Flutter UI locks up. Could a chosen image size be generated if passed to .getImage()?