Android : Xlabs Camera, create thumbnail for Android

In my PCL im using Xlabs code for taking a picture:

public async Task<MediaFile> TakePicture()
        {
            Setup ();

            ImageSource = null;

            return await _Mediapicker.TakePhotoAsync (new CameraMediaStorageOptions {
                DefaultCamera = CameraDevice.Front, MaxPixelDimension = 400
            }).ContinueWith (t => {
                if (t.IsFaulted)
                {
                    Status = t.Exception.InnerException.ToString();
                }
                else if (t.IsCanceled)
                {
                    Status = "Canceled";
                }
                else
                {
                    var mediaFile = t.Result;
                    ImageSource = ImageSource.FromStream(() => mediaFile.Source);

                    return mediaFile;
                }

                return null;
            }, _scheduler);
        }

This works fine and the image gets stored on the devices disc. What I would like to do is to create a smaller, thumbnail-version of the image that i can store in my SQliteDB.

Maybe I have a class like this:

  public class user
    {
        public int Id { get; set; }
        public TYPE?? TheThumbnail { get; set; }
        public string Name { get; set; }
    } 

I appreciate the help, thank you