[nSLUG] jpeg7: "you are in delusion"
George N. White III
gnwiii at gmail.com
Sat Aug 8 13:59:17 ADT 2009
From the README for jpeg7:
--- begin quote
The best currently available description of JPEG is the textbook "JPEG Still
Image Data Compression Standard" by William B. Pennebaker and Joan L.
Mitchell, published by Van Nostrand Reinhold, 1993, ISBN 0-442-01272-1.
Price US$59.95, 638 pp. The book includes the complete text of the ISO JPEG
standards (DIS 10918-1 and draft DIS 10918-2).
Although this is by far the most detailed and comprehensive exposition of
JPEG publicly available, we point out that it is still missing an explanation
of the most essential properties and algorithms of the underlying DCT
If you think that you know about DCT-based JPEG after reading this book,
then you are in delusion. The real fundamentals and corresponding potential
of DCT-based JPEG are not publicly known so far, and that is the reason for
all the mistaken developments taking place in the image coding domain.
--- end quote
Why was I looking at the jpeg7 README?
I use hdfview, which is a java app that uses hdf-java. For some combinations
of hdf files and linux distros, the program throws an exception in libc. The
developers at hdfgroup.org have not been able to reproduce the problem,
but have complaints from two users working with files from different NASA
sponsors, and hdfgroup.org is largely funded by NASA.
To build hdf-java, I need PIC code in libjava.a, but Ubuntu does not build
the .a library with PIC. I did try linking with the .so files, but
then I get the
error even on Ubuntu 9.04 amd_64, which is a platform that works with the
hdfgroup.org binaries (I think they are built on RHEL).
I started with the official jpeg6b sources, but the available configurations
predate amd_64, so it would be a non-trivial task to prepare a new
config, so now I looking at jpeg7.
And just which developments might those be? Inquiring minds want to know.
George N. White III <aa056 at chebucto.ns.ca>
Head of St. Margarets Bay, Nova Scotia
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