The attempt to produce a cartographic desktop AR environment, having in mind the objectives stated previously in the paper, has certain advantages; some limitations are, however, unavoidable. Both positive and negative aspects can be summarized in terms of Data capture, Equipment and Tools, and Presentation of results. Most of the difficulties encountered are related to limitations and obstacles present during Data capture, Narrow streets, for instance, seem to be a major obstacle when recording buildings (A photomosaic from overlapping images can offer a solution, but increases the amount of work. Other solutions, such as the use of wide-angle lenses, are assumed not available for a common video camcorder). Other commonly encountered obstacles include lampposts, columns, tree-trunks and foliage, parked cars etc. Some of these are impossible to eliminate from images; often, therefore, they are recorded as part of building facades. Both Equipment for data capture (video) and Tools for data processing and display are easy to use, flexible and low cost. Although a variety of software tools was used for the step by step processing of the data, these are all general purpose, user-friendly, inexpensive and nowadays commonly available. The CAD environment used for the presentation -chosen for pragmatic reasons mentioned previously (the need for fast and cheap production and equipment)- is the simplest that can be used for AR purposes, as already mentioned, its most serious weakness being the lack of immersion. This can be overcome, to adegree, by the production and viewing of stereo images. The result has many options for overview of a project within a broader geographic area, although the data collection is done terrestrially. Furthermore realism is simulated to a satisfactory degree and the existing photorealistic effects can be manipulated at will (e.g. solar study, view of vegetation in various seasons etc.). Another advantage is the possibility offered by the CAD environment to reconstruct traditional inverse photogrammetric products (photo mountings, simulation of photographic shots) and even expand them through new products (i.e. video sequences with the new situation viewed in a realistic background).
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