Research on the Storage Method of Raster Image Based on File Directory

In order to increase the efficiency of raster image storage, a block file directory tree (BFDT) framework is introduced in this paper as a new index structure of raster blocks. Through changing the container of raster blocks from the database to the file system, and depends on the file system´s storage advantage of high efficiency, the BFDT framework improves the storage method used by GeoRaster. The BFDT framework is designed to have a quad-tree structure, and implemented based on the open source database management system-Ingres. For verification, some comparative experiments of raster image storage are conducted. The experimental results prove that the performance of the BFDT framework is more efficient than GeoRaster. Therefore the BFDT framework can effectively solve the storage problem of massive raster image data.