Arithmetic coding in Fedora libjpeg (bug #639531)

[Gregory Maxwell]

On Sat, Oct 2, 2010 at 1:34 PM, Paul F. Johnson
<paul at all-the-johnsons.co.uk> wrote:
> Hi,
>
>> "You shall not create images with arithmetic coding" is like saying "You
>> shall not create images of the flying sphagetti monster." It's not up to
>> Fedora to make this choice for me.
>
> It is though - you have chosen to use Fedora therefore have to live with
> the decisions the Fedora legal people (I'm assuming they said no to
> arithmetic coding) have said goes.

The relevant patent expired last year. I believe the SUN OMS team had
researched this extensively as they were using the JPEG arithmetic
coder in their aggressively researched royalty free video codec
design.

If someone doing legal research on this needs more information, you
can contact me offlist and I can connect you with people who have
researched this topic and may be willing to provide some useful
pointers.

2010/10/2 Björn Persson <bjorn at xn--rombobjrn-67a.se>:
> It's well known around the Internet that to achieve compatibility you should
> be conservative in what you send and liberal in what you accept. Applied to
> JPEG: Use only Huffman coding when encoding – except maybe if you know that all
> recipients can handle arithmetic coding – but support both encodings when
> decoding.

Absolutely. This is an excellent argument and I think is sufficient to
justify the inclusion alone.