<title>Radiological image compression: image characteristics and clinical considerations</title>

Abstract

Since most medical images are composed of different image characteristics, it has been demonstrated that applying a combined method to various image components can preserve a higher image quality. The major image components are: (a) smooth areas, (b) sharp edges, (c) texture, and (d) noise. In practice, sharp edges and general textures are two main components to be concerned for radiological images compression. A unified perspective of transform coding is reviewed to find out how a high compression ratio can be achieved with a lossy compression technique. Theoretically, the image quality in resolution power is associated with a composed module transfer function (MTF) when an image obtained from x-ray device coupling with a digitization module and processed by a lossy compression. It is very difficult to use a global MTF (or a band of MTF) to represent such a system. In this paper, we concentrate on clinical considerations for various applications in radiological image compression. Three different applications and associated compression strategies are discussed. Based on these compression strategies, we believe that many compression methods are suitable for clinical implementation with some clinical guidance and technical modifications.