After some research, i finally got the solution.
All to do is to convert all Image objects into Strings, so it can be serializable.
At the server side:
public Bitmap img;
public String ImageToString(Bitmap img)
{
byte[] byteArray = new byte[0];
using (MemoryStream stream = new MemoryStream())
{
img.Save(stream, System.Drawing.Imaging.ImageFormat.Png);
stream.Close();
byteArray = stream.ToArray();
}
return Convert.ToBase64String(byteArray);
}
At the client side:
public Bitmap img;
public Bitmap StringToImage(string imageString)
{
if (imageString == null) throw new ArgumentNullException("imageString");
byte[] array = Convert.FromBase64String(imageString);
Bitmap image = (Bitmap)Bitmap.FromStream(new MemoryStream(array));
return image;
}