WPF Images

hi, thanks for great answer 

i had problem in convert image in wpf to byte[] to send it to database

in window form is used this code 

 MemoryStream ms = new MemoryStream();
 picturebox.Image.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);
 byte[] pic_arr = new byte[ms.Length];
 ms.Position = 0;
 ms.Read(pic_arr, 0, pic_arr.Length);

in wpf 

picturebox.image  will be Image.Resourse

but i do not know the rest 

Image.Resourse.save,,,,,,it does not work 

please if you can help me