Accession Number : ADA298558

Title :   A Comparison of the Compressed Aeronautical Chart and Compressed ARC Digitized Raster Graphics Compression Techniques for ARC Digitized Raster Graphics Compression.

Descriptive Note : Final rept.,

Corporate Author : NAVAL RESEARCH LAB STENNIS SPACE CENTER MS

Personal Author(s) : Guidry, Ruth A. ; Shaw, Kevin B.

PDF Url : ADA298558

Report Date : 14 JUL 1995

Pagination or Media Count : 17

Abstract : This study compares two Defense Mapping Agency databases, the Navy Standard Compressed Aeronautical Chart (CAC) database and the Air Force Compressed Equal Arc-second Raster Chart Digitized Raster Graphics (CADRG) database, that are made up of compressed ARC digitized raster graphics data. There continues to be a large demand for raster map data in both the Department of Defense and commercial communities. Attention is focused on the various algorithms used to implement the compressions for each database. Both databases follow the same three basic steps, although the CADRG database employs some filtering techniques as well. Results show that the CADRG database, which achieves a 55:1 compression, outputs images that are slightly sharper, clearer, and of a higher resolution than the CAC images, due in large part to the additional filtering techniques. The CAC database, which achieves a 45:1 compression, was developed several years earlier than the CADRG database and was proven in combat situations during Operation Desert Storm. Both databases suffer loss of data during compression, and the actual differences between the images output by the databases are slight.

Descriptors :   *DATA BASES, *AERONAUTICS, *COMPUTER GRAPHICS, *DATA COMPRESSION, *CHARTS, *DIGITAL MAPS, *RASTERS, ALGORITHMS, OUTPUT, MILITARY OPERATIONS, REQUIREMENTS, WARFARE, DEPARTMENT OF DEFENSE, IRAQ, COMMERCE, COMPARISON, HIGH RESOLUTION, IMAGES, FILTERS.

Subject Categories : Cartography and Aerial Photography
      Computer Programming and Software
      Computer Systems

Distribution Statement : APPROVED FOR PUBLIC RELEASE