Bitmap bmp = new Bitmap("d:\\temp\\DSC04618.jpg");
MemoryStream mstream = new MemoryStream();
bmp.Save(mstream, ImageFormat.Jpeg);
byte []bytes = new byte[mstream.Length];
mstream.Read(bytes, 0, (int)mstream.Length);
for more details please see
http://bimbim.in/post/2010/08/21/How...b-service.aspx