Spatial Indexing into Compressed Raster Images: How to Answer Range Queries Without Decompression

The maintenance of large raster images under spatial operations is still a major performance bottleneck. For reasons of storage space, images in a collection, such as satellite pictures in geographic information systems, are maintained in compressed form. Instead of performing a spatially selective operation on an image by first decompressing the compressed version, we propose to perform queries directly on the compressed version of the image. We suggest a compression technique that allows for the subsequent use of a data structure to guide a spatial search. In response to a range query, our algorithm delivers a compressed partial image. Experiments show that the new algorithm supports spatial queries on satellite images efficiently. In addition it is even competitive in terms of the compression that it achieves.

• Type: Conference
• Year: 1996
• Where: IWMMDBMS
• Authors: Renato Pajarola, Peter Widmayer
• Keywords: Compressed Partial Image, IWMMDBMS 1996, Large Raster Images, Spatial