Principles of Digital ‘Panneau’ Cartographic Visualisations

Abstract

A significant development in visualisation methods based on perspective rules has been observed recently. It is manifested in some examples worth mentioning, such as virtual walks, visualisations of 3D objects and panoramas. In order to assist users in the perception of such presentations, they are supplemented by typical cartographic elements, such as fragments of maps or city plans. One kind of such cartographic works, recently slightly forgotten, but still worth attention, are the so-called panoramic maps of ‘panneau’ type. A panoramic map of ‘panneau’ type is a form of a view panorama of 360° horizon, projected on a flat plane in the form of a closed circle. Landscape ‘panneau’ presentations are usually produced for characteristic points of observation, mainly in mountainous areas, but also at points of observation in cities (e.g. the Arch of Triumph in Paris) and they are located on special viewing platforms. They are additional tourist attractions and perform an educational function. ‘Panneaus’ are usually engraved or etched on special metal plates, on china or they are printed on other media, for example, on paper. The objective of such imageries was to allow users to familiarize themselves quickly with the landscape which may be seen from a given point of observation, directly at that point – and thus to provide them with the possibility to locate and identify (by name) such geographical features as mountain peaks, passes, localities and other characteristic points. This paper presents the principles, methodology and technology used to create panoramic images of ‘panneau’ type using digital techniques. The starting point to create the ‘panneau’ is a 3600 rectangular panorama of a given horizon. Depending on the image type, which should be obtained, appropriate technology of image recording is applied. Panoramic images acquired with the use of a standard analogue or digital camera are photomontages combining individual photographs that belong to a series of images encompassing the entire scene. Single shots must be geometrically and tonally matched, so that it should be difficult to differentiate them. In digital techniques, special software tools are applied for combining individual images, such as Panorama Factory or Panorama Maker.