1、已知路径，加载本地图片到Image中
Image img = Image.FromFile("路径");
2、数据库中读取二进制图片
string strSql = "Select Top 1 ImageContent From TT_ImageFileSave)";
Byte[] byteImage = new Byte[0];
byteImage = (Byte[])(DbHelperSQL.GetSingle(strSql));
MemoryStream stmBLOBData = new MemoryStream(byteImage);
picCarInfo.Image = Image.FromStream(stmBLOBData);
3、将已知路径图片转换为二进制
string strImagePath = AppDomain.CurrentDomain.BaseDirectory + "//Tickets//Ticket.jpg";
FileStream fileStream = new FileStream(strImagePath, FileMode.Open, FileAccess.Read);
BinaryReader binaryReader = new BinaryReader(fileStream);
byte[] byteImage = binaryReader.ReadBytes((int)fileStream.Length);
binaryReader.Close(); fileStream.Close(); File.Delete(strImagePath);
return byteImage;
4、将现有Image图片转化为二进制
MemoryStream mStream = new MemoryStream();
byte[] bytImagedata = null;
pictureBox1.Image.Save(Ms,System.Drawing.Imaging.ImageFormat.Bmp);
bytImagedata = mStream.GetBuffer(); return bytImagedata;
http://www.cnblogs.com/zhangpengshou/archive/2011/04/24/1749391.html