Information Technology Reference
In-Depth Information
in the form of rules, which constitute the building blocks of the knowledge base. The
application logic and the procedural information of the system are described by rules and
operated on objects, classes and slots [Stefanakis, Tsoulos 2005]. The structure and
organization of the knowledge base is critical for efficiency and the overall performance of
the system. Only features referred to the usage of a map can be presented and, on the other
hand, only important elements can be shown when there are too many features [Hua, 1991].
That is why it is necessary to include all the potential factors to the database when designing
such a system, or it is necessary to focus only on some issues in a map-making process.
In disrespect of the basic rules, there may be restrictions of expressing the ability of the map
or the cartographic expression becomes unreadable. Intelligent system can assist to the
correct selection of colour in accordance with the rules of cartography. E.g. conservation
principle of conventionality (blue colour for waters, brown colour for contour lines),
conservation principle of associativity (green forests for topographic maps), the right choice
of colours for the qualitative data or the correct shade of colour for expressing the intensity
of the phenomenon. They can take into consideration the type of imaging methods and the
people suffering from daltonism etc. There is also an art to displaying information visually,
and sometimes principles contradict each other [Andrienko, Andrienko, Voss, 2002].
The basic principle of the intelligent system is to divide the whole process into subsections,
which affect the result. The resulting proposed system must be coherent and
comprehensive. Good comprehensive intelligent system for thematic cartography should be
able to propose appropriate solutions of the problem. Excellent intelligent system should be
even able to offer not only one possible solution but also give the explanation and
justification to the user.
3. Cartographic intelligent systems with a specific knowledge
With the development of digital cartography and transfer maps to digital form there is an
increasing need to vectorize and generalize properly. Both processes are widely used in the
last decade. This process, however, requires the presence of expert and correction of the
process. Software that directly vectorize scanned image maps can be divided into automatic
and semi-automatic, depending on the modes of information processing [Hori, Tanigawa,
1993], [Eikvil, Aas, Koren, 1995]. Most of current automatic vectorial systems apply the same
method for all maps and do not take into consideration their different nature. It is expected
from the user as the most accurate manual setting as possible, which presupposes good
knowledge of the problems and knowledge of the system used [Hori, Tanigawa, 1993]. One
option is to use the knowledge base and thus reduce the overall demand of cartographic
literacy of the users and facilitate the whole process of vectorization. In conjunction with the
knowledge base we get a system that is able to give results very similar to the of outputs
highly sophisticated manual digitization. In addition, it provides more agreeable user
interface which allows the selection of appropriate parameters in accordance with the visual
information contained in the original map.
Even generalizing algorithms of existing systems often ignore the role of maps or fuzzy
logic to optimize the process. There are thus not able to extract hidden information. The
specific knowledge, which is not taken into account in so far known algorithms, is required
