<title>Lossless compression of prepress images using a novel color decorrelation technique</title>

Abstract

In the pre-press industry color images have both a high spatial and a high color resolution. Such images require a considerable amount of storage space and impose long transmission times. Data compression is desired to reduce these storage and transmission problems. Because of the high quality requirements in the pre-press industry only listless compression is acceptable. Most existing listless compression schemes operate on gray-scale images. In this case the color components of color images must be compressed independently. However, higher compression ratios can be achieved by exploiting inter-color redundancies. In this paper a new listless color transform is proposed, based on the Karhunen- Loeve Transform (KLT). This transform removes redundancies in the color representation of each pixel and can be combined with many existing compression schemes. In this paper it is combined with a prediction scheme that exploits spatial redundancies. The results proposed in this paper show that the color transform effectively decorrelates the color components and that it typically saves about a half to two bit per pixel, compared to a purely predictive scheme.© (1998) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.