JPEG and JPEG2000

This chapter focuses on the lossy compression component of the Joint Photographic Experts Group (JPEG) and the JPEG2000 standards. Joint Photographic Experts Group lossy compression entails an irreversible mapping of the image to a compressed bitstream, but the standard provides mechanisms for a controlled loss of information. Lossy compression produces a bitstream that is usually much smaller in size than that produced with lossless compression. The JPEG standard has proved to be a tremendous success over the past decade in many digital imaging applications. However, as the needs of multimedia and imaging applications evolved in areas such as medical imaging, reconnaissance, the Internet, and mobile imaging, it became evident that the JPEG standard suffered from shortcomings in compression efficiency and progressive decoding. This led the JPEG committee to launch an effort in late 1996 and early 1997 to create new image compression standard. The intent was to provide a method that would support a range of features in a single compressed bitstream for different types of still images such as bi level, gray level, color, multicomponent—in particular multispectral—or other types of imagery.