Back to articles
Volume: 1 | Article ID: art00044
Color Palette Reduction and Enhancement Techniques
  DOI :  10.2352/CIC.1993.1.1.art00044  Published OnlineJanuary 1993

The Naval Research Laboratory's Map Data Formatting Facility is developing a seamless, compressed, digital database of the world called the Compressed Aeronautical Chart (CAC). The CAC consists of scanned, aeronautical chart images. The CAC's primary purpose is to support Navy and Marine Corps aircraft mission planning and digital moving map systems. However, other users on various platforms have expressed interest in using the CAC. Therefore, the CAC must be capable of adapting to the graphics capabilities of other platforms.The CAC uses a set of custom color palettes that consists of 240 distinct colors. Each pixel from the precompressed data at full color (24-bit) indexes to its closest color palette entry as decided by its Euclidean distance. Custom color palettes tend to maintain color integrity between the CAC and the original data.Since graphics capabilities vary from platform to platform, the ability to reduce and remap a color palette is a useful tool. This paper describes the technique chosen to remap the CAC color palettes to the desired, reduced set of colors. An enhancement technique that uses a contrast stretch algorithm is also described. The enhancement is achieved by first calculating a given palette's luminance (Y) values. Then, a ratio of the contrast stretch luminance to the original luminance value is derived for each color in a given color palette.

Subject Areas :
Views 5
Downloads 0
 articleview.views 5
 articleview.downloads 0
  Cite this article 

Michael E. Trenchard, Lancelot M. Riedlinger, Stephanie A. Myrick, Marlin L. Gendron, "Color Palette Reduction and Enhancement Techniquesin Proc. IS&T 1st Color and Imaging Conf.,  1993,  pp 178 - 180,

 Copy citation
  Copyright statement 
Copyright © Society for Imaging Science and Technology 1993
Color and Imaging Conference
color imaging conf
Society of Imaging Science and Technology
7003 Kilworth Lane, Springfield, VA 22151, USA