ILIAD — a High Level Dialogue System for Picture Analysis

ILIAD is a comprehensive digital picture analysis system that interacts with the user, through a high level language. The system is constructed to be a general tool for picture processing and picture analysis in different environments. It runs on a general purpose computer but it also contains provisions for utilizing different kinds of special hardware.The high level language makes ILIAD programmable at monitor level. This means that different picture processing algorithms can be programmed directly using the PASCAL like command language.The ILIAD system includes a procedure facility. A procedure is a self contained piece of ILIAD code stored in a special library or an external independent program that communicates with ILIAD via certain parameter transfer functions. Using such procedures a hierarchical structure of procedures can be built. This means that each picture processing problem can be expressed in such a structure, which simplifies the use of the system. Thus the experienced user can use the full system while a novice user may restrict himself to preprogrammed procedures which are simpler to use.The system has been implemented on a VAX 11/780 under the operating system VMS and on a PDP 11/55 using RSX-11M. It is mainly programmed in PASCAL and is thus transportable to other computers. The design of the system was influenced by experiences gained from earlier picture analysis systems.In this paper the first section, a general introduction, is followed by a short overview of the ILIAD system in section two. The reader who only needs a brief description of the system may restrict study to these two sections. The rest of the paper gives a more detailed description of the ILIAD language and its implementation. In the last two sections, an example of an application is given and some possible future developments are discussed.