Mathematical Backgrounds of JPEG Image Compression Method

Abstract

JPEG (,Joint Photographic Experts Group) is a standard compression method for continuous-tone still image both in full-color and in gray scale. JPEG is intended for ''real world" scene and the standard aims to be generic, to support a wide variety of applications for continuous-tone still images. To meet various needs of many applications, the JPEG standard includes two basic compression methods, each with various modes of operations. A DCT- based method is specified for "lossy'' compression, and a predictive method for "lossless" compression. JPEG features a simple lossy technique known as the Baseline method, a subset of the other DCT-based modes of operation. The Baseline method has been by far the most widely implemented JPEG method today, and is sufficient in for a large number of applications. This article provides an overview of the JPEG, and focuses in detail on the Baseline method.