As a part of the development of the Italian Cartographic Reference System, the Italian Ministry of the Environment has developed, in collaboration with Planetek Italia, a public web site (www.atlanteitaliano.it), allowing unrestricted Internet access to various types of maps and photographic images covering the whole of Italy. The types of data available on-line include black and white and colour orthophotos at 1 meter resolution (nominal scale 1: 10.000); maps of the Italian Geographic Military institute (IGM, scale 1: 25.000, 1: 100.000, 1: 250,000 1: 1.000.000); and a digital elevation model (DEM). The data, compressed in ECW format, are distributed using Image Web Server with the specific advantage that the imagery may be accessed via the Internet in real time in two ways; either through the website using a common browser or directly inside any common supported desktop GIS application using the individual image URL (only registered and entitled users are permitted access to the URL’s).
By going to the website users are given three different ways to view the cartography: single view, double view and transparency.
Using ER Mapper, the thousands of individual images were all mosaiced together into single images, one for each data type for a specific region. After mosaicing, the images were colour balanced and then directly compressed into ECW format. This format produces a dramatic reduction in the size of the image files and permits the high speed serving of the data by Image Web Server.