A tile-based system for the rapid display of symbolized Digital Nautical Chart data

For efficient retrieval and display of Digital Nautical Chart (DNC^®) imagery, a tiled-based approach is presented. By preprocessing the data into persistent image tiles, the presented method can minimize or eliminate image processing steps during the retrieval process. Tile-based approaches define constant image sizes and scales for geographic regions, therefore tiles can be pre-generated and stored in a format needed for transmission to users. This greatly improves the performance of applications that visualize DNC^® data and allows for advanced caching of DNC^® imagery tiles. In addition, the evenly-spaced and commonly-sized images are stored in files that are easily indexed allowing for simple and fast lookup of DNC^® imagery tiles for a given geographic area.