myImageStream, myTumbsStream - MemoryStream объекты в которых сохранено
изображение и его tumbinail.
...
OracleConnection conn = new OracleConnection(ConfigurationSettings.AppSettings["ConnectionString"]);
OracleCommand cmd = conn.CreateCommand();
cmd.CommandType = CommandType.StoredProcedure;
cmd.CommandText = "INTRANET.PKG_IMAGES.add_image";
		
cmd.Parameters.Clear();
cmd.Parameters.Add("t_userIP", OracleType.VarChar,255).Value = imageName;
cmd.Parameters.Add("t_imageNormal", OracleType.Blob,myImageStream.Capacity).Value = myImageStream.GetBuffer();
cmd.Parameters.Add("t_imageSmall", OracleType.Blob,myTumbsStream.Capacity).Value = myTumbsStream.GetBuffer();
			
conn.Open();
cmd.ExecuteReader(CommandBehavior.CloseConnection);

System.Data.OracleClient.OracleException: ORA- 06550 : line  1 , column  7 : PLS- 00306 : wrong number or types of arguments in call to 'ADD_IMAGE' ORA- 06550 : line  1 , column  7 : PL/SQL: Statement ignored 

procedure add_image(
  t_imageName in images.imageName%type,
  t_imageNormal in images.imageNormal%type,
  t_imageSmall in images.imageSmall%type) as
begin

  insert into images
  (imageName,imageNormal,imageSmall)
  values
  (t_imageName,t_imageNormal,t_imageSmall);
  commit;

end add_image;