Discrete Wavelet Transformations: An Elementary Approach with Applications

CHAPTER 12

THE JPEG2000 IMAGE COMPRESSION STANDARD

In 1992, JPEG became an international standard for compressing digital still images. JPEG is an acronym for the Joint Photographic Experts Group that was formed in the 1980s by members of the International Organization for Standardization (ISO) and the International Telecommunication Union (ITU). The JPEG compression standard remains very popular. According to Charrier et al. [16], 80% of all images appearing on the World Wide Web¹ are stored using it. Despite the popularity of the JPEG standard, members of JPEG decided that the algorithm could be improved in several areas and that it should be enhanced so as to meet the growing needs of applications using digital images. In 1997, work began on the development of the improved JPEG2000 compression standard. The core system of the JPEG2000 compression method is now a published standard by the ISO (ISO 15444). Unfortunately, due to patent issues involving the encoding method, the complete algorithm is not yet an ISO standard. Thus, JPEG2000 is not supported by Web browsers such as Microsoft’s Internet Explorer or Mozilla’s Firefox. It is hoped that once the patent issues are resolved, JPEG2000 will replace the current JPEG standard as the most popular tool for image compression.

One of the biggest changes in the new JPEG2000 standard is the fact that the biorthogonal wavelet transform has replaced the discrete cosine transform as the preferred method for organizing data in a way ...