provides the necessary parameters ( X,y,w,z). In 
this process he does not need to know much of the 
graphic system he is using. 
In fact the primitives are acting on the 
represented knowledge using the frame language 
referred to previously. This makes the user's 
procedures and parameters specification a high 
level abstraction task, 
As mentioned before the knowledge representation 
and the inference rules are specified using the 
PROLOG language. The PROLOG language is a 
declarative language that permits easy rules 
coding for users, Besides it has an inference 
motor adequate for the proposed environment. 
The environment can be adapted to any other 
domain as mentioned previously, Other inference 
rules may be needed and then the user must code 
other primitives to perform the tasks, In the 
Digital Image Processing domain the environment 
may be able to translate queries as in example 2 
(interactions in Portuguese). 
Exemplo 2: 
USUARIO : Suavizar a imagem. 
(USER : Smooth image) 
AMBIENTE : Especifique a imagem a ser 
filtrada. 
( ENVIRONMENT : Specify the image to be 
filtered) 
USUARIO : (Fornece o nome da imagem) 
( USER: (Provides the name ) 
AMBIENTE : O filtro passa-baixa deve 
preservar a borda? 
(ENVIRONMENT : Is it an edge preserving 
smoothing filter?) 
USUARIO : (0 usuario pode responder de 
acordo com a pergunta do sistema ou pode 
indagar o que significa preservar a borda, ao 
que o sistema pode atender explicando o 
efeito de preservarcao da borda e 
exemplificando) 
(USER : May answer accordingly or ask about 
edge preserving which the environment may 
explain and give examples). 
All the information provided in example 2 may be 
Stored so that in the next user's interaction 
requesting the same processing the environment 
can promptly perform its tasks recalling the 
definitions stored. 
2.3 Results Obtained 
The environment discussed here is implemented for 
the 2D Computer Graphics domain. Instead of 
trying to solve all of the problems concerned to 
2D transformations the work aims to show the 
usefulness of designing Natural Language 
environments for Man-Machine Interaction in 
system development in any application domain. The 
task involves people dealing with Artificial 
382 
Intelligence such as Knowledge Engineers, and 
domain experts such as those working in Computer 
Graphics, Remote Sensing, Image Interpretation, 
Digital Signal Processing, etc. 
The way the prototype is designed permits some 
interactions with the user, So that environment 
successfully performs tasks as stated in example 
le While building up his request the user 
maintains a high level dialog with the machine. 
That is, he specifies everything in his own 
language and does not get involved with detailed 
parameters specification, Thus establishing an 
improved Man-Machine Interaction. 
Providing the linguistic universe for Natural 
Language interaction the environment can show its 
efficiency with people without much experience in 
computer use and/or the application domain 
considered, The storage of knowledge involved in 
problem solution permits that most of the 
situations be treated automatically from the 
user's viewpoint thus avoiding redefinition of 
the user's intention, 
3, CONCLUSIONS 
The prototype developed showed the possibility of 
using Natural Language in knowledge-based systems 
which improves Man-Machine Interaction. Thus 
users can face computational systems as real 
helping tools once they do not need to get 
involved with detailed specifications that make 
them learn several lessons on systems use before 
efficiently use them to solve their problems. 
Then time used before for training purposes can 
now be dedicated to new solution strategies and 
methods discoveries. Besides, the tasks can be 
executed automatically under user's viewpoint, so 
that, the efforts for problem solution can be 
measured and evaluated. 
Natural Language has not been used in system 
design because of the problems involved, It is a 
very dynamic subject where the rules are 
constantly changing according to customs, 
culture, etc., within a region. This means new 
rules and data storage. Also, the same feeling 
can be expressed in several different ways which 
requires a complete linguistic knowledge 
representation that may require great memory 
capacity from the hardware used,  Restricting the 
domain it is possible to use free NL to treat a 
reduced number of situations, 
The initial work objective was to design a system 
where the Remote Sensing experts would perform 
several Digital Image Processing activities, 
specially those related to Image Interpretation 
involving different knowledge sources. The 
greatest problem found concerned image knowledge 
representation, And then, an environment for 2D 
Computer Graphics domain was developed. The 
objects treated in this domain are simple to be 
represented, However, image knowledge 
representation has been studied by some authors 
already and the prototype described can now be 
tested in Image Processing. The same system 
philosophy design has been used to develop an 
interface for an image processing software that 
performs morphological processing on images. 
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