A WEB DIALOGUE APPLICATION FOR CREATIVE PORTRAYAL
S. Christophe
Institut Geographique National (IGN France) COGIT Laboratory
sidonie.christophe@ign.fr
While Web access to mapping tools become more and more democratic, users
face difficulties to conceive personalized and effective legends adapted to
their taste and needs. Firstly, they seldom have technical and theoretical
skills to design efficient maps. Moreover, they may lack creative know-how to
draw innovative maps. Lastly, the creation of a legend via a standard graphic
interface may require time. Thus it is relevant to assist users in creating
innovating and customised legends. This requires methods to facilitate the
creation process and to ensure the semiological quality of map.
Our paper
deals with the design and implementation of such methods. Our objective is to
provide users with an interface to create innovating legends that both fit
their taste and needs and complies with cartographic rules.
A first
important choice has been to build a dialogue interface and not a classical
query or browsing interface. Dialogue techniques are actually required to
represent the user needs and to find a compromise solution between those needs
and what is cartographically correct.
An important result we rely on is the work of [Hubert]. He proposed a
mechanism of man-machine dialogue based on map samples in order to converge
towards a satisfying parameterisation in generalisation algorithm. We re-use
his proposal: as users could face problems with mapping semantics, the dialog
must be based on analogies, i.e. on map samples.
Our challenge is to define communication acts and associated methods to
manipulate samples – to select them, to build new ones. The first communication act of the
system is to build and to propose to the user a selection of map samples. Then
the user should express statement like ‘I don’t like the colour’ or ‘I like
this sample’. The system iterates a proposal which is more and more relevant
and more or less varied depending of the dialogue stage.
We propose a model of legend made of themes, objects, relations and
colours, which are halfway goals to be reached during the dialogue. In that way
we propose four associated strategies: a colour palette to define, theme by
theme to process, significant objects to choose, a map sample to refine.
Whatever order the user chooses to treat of this strategies, the ultimate goal
is reached when the intermediates are too. Lastly we consider that the legend
is satisfying when our model of legend is entirely completed.
Hubert F.,
Ruas A., 2003, A method based on samples to capture user needs for
generalisation, 5th Workshop on Progress in Automated Map
Generalization, Paris, France, 28-30 April 2003.