Obtaining the JPEGtool package

Introduction to
Information Theory and Data Compression

Darrel Hankerson, Greg A. Harris, and Peter D. Johnson Jr.

Obtaining the documentation and scripts

A package of Octave and Matlab scripts has been written to accompany material in this book. Documentation appears in Appendix A of the textbook, and is also available in Portable Document Fromat (PDF) as jpegtool.pdf (try jpegtool_compat.pdf if your software complains), or in PostScript form as jpegtool.ps.gz (compressed with gzip). PDF readers for many platforms may be obtained from Adobe; a very good alternative is xpdf.

The Linux Journal article Transform Methods and Image Compression (January 1999, pages 18-24), adapted from the text, covers some of the material; fetch tmic.pdf or tmic.ps.gz.

The scripts can be used to study JPEG-like schemes. At the simplest level, a standard JPEG transform and quantization scheme can be requested and the results displayed with commands of the form

The image at the top of this page shows the 64 basis elements in the transform used in JPEG, and was generated with ``imagesc(basisgrid(8))''.

The scripts are freely-distributable under the GNU General Public License, and are packaged as jpegtool.tar.gz (gzip), jpegtool.tar.Z (Unix compress), jpegtool.zip (Info-ZIP), and jpegtool.sit.hqx (binhexed for Mac). They are also available unpackaged.

Information Theory and Data Compression / hankedr@mail.auburn.edu / Octover 1999