[nSLUG] jpeg7: "you are in delusion"

Daniel Morrison draker at gmail.com
Sat Aug 8 14:52:37 ADT 2009

Hey George,

A little bit "stream of consciousness" writing here... not quite sure
what you're getting at!

2009/8/8 George N. White III <gnwiii at gmail.com>:
>  From the README for jpeg7:
> 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.

I don't have any reason to disrespect these folks, but... the
fundamentals of DCT-based JPEG are not publicly known? Really? After
almost 20 years of a phenomenally successful published standard? And
these free-software coders are keeping the knowledge secret
because...? Sounds to me like the README author has a little chip on
his/her shoulder...

> Why was I looking at the jpeg7 README?

Yes indeed, why?

> 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).

Disconnect here -- hdf-java needs PIC libjava.a, and so... you start
with jpeg6b sources.

I confess I have no idea what hdf-java is, but you might help us
establish the link... how are you getting to the jpeg sources based on
a need for libjava.a?

> 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.

What developments are you talking about? You're losing me here... From
jpeg6b -> jpeg7? Well, there are a number of new features listed on
the page that you referenced in your previous email...

Hope this helps,


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