A Tile-Based System for the Rapid Display of Symbolized Digital Nautical Chart Data

For efficient retrieval and display of Digital Nautical Chart (DNC (R)) 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 (R) data and allows for advanced caching of DNC (R) 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 (R) imagery tiles for a given geographic area.