The new contribution of this work combines the design of a comprehensive digital image database on-line query access strategy through the development of a feature library, image library and metadata library and the necessary matching tools. The exponential network growth and the global connectivity reached in the last few years have had a great impact on the requirements of contemporary and next-generation geographic information systems. The capability to access and deliver data efficiently can be achieved by enabling a geographic information system to transmit data progressively. Progressive transmission of raster images over the World Wide Web has been successfully applied to provide the user with coarser versions of the data before downloading a complete image. This process is particularly useful when trying to access remote data through a slow communication link or in the case of wireless communication, and when datasets are very large.
Progressive transmission is still a challenging topic in the vector domain, however.
Increasing or decreasing the level of detail of a vector dataset is a complex and time-consuming process. A possible solution relies on the pre-computation of multiple coarser versions of the data to be stored on the server and delivered progressively upon request. The generation of pre-computation of multiple coarser versions of the data to be stored on the server and delivered progressively upon request. The generation of such versions must be done on the basis of sound cartographic principles to preserve consistency. Within this framework, we have developed a model for generating less detailed representations of maps in vector format within a spatial database.