1) Convert the Image property of the PictureBox to a stream of bytes.
2) Send the stream of bytes to the client.
3) Convert the bytes to an Image.
4) Load the Image into a PictureBox.Image property.
Convert Image to byte[] array:
MemoryStream ms = new MemoryStream();
imageIn.Save(ms,System.Drawing.Imaging.ImageFormat.Bmp);
return ms.ToArray();
Convert byte[] array to Image:
MemoryStream ms = new MemoryStream(bytes);
Image returnImage = Image.FromStream(ms);
return returnImage;