Bug#734373: OpenCV: please build SIFT and SURF modules

[Jonas Meurer]

Hello,

> > unfortunately, the Debian OpenCV packages don't provide the SIFT and
> > SURF modules.
> >
> > It seems like these modules were outsourced into a nonfree module, and
> > need to be enabled explicitely at build time with cmake flag
> > "-DBUILD_opencv_nonfree=ON".
> >
> > I didn't check the license of these modules, but as long as it's
> > possible to distribute them in non-free, I suggest to build them (or at
> > least make it easy to enable them at build time by simple flag in
> > debian/rules).
> 
> I understand that the processing speed of OpenCV can be improved by
> using a nonfree module. And, I also understand that many users want to
> use this module.
> 
> I think you also know that, because it contains the problem of patent,
> I have been removed from the source code in Debian this module.
> I do not know whether there is a need to remove the source code, but
> think of safety, I am that you do not distribute the source code in
> Debian.
> 
>   http://www.cs.ubc.ca/~lowe/keypoints/
> 
> You can see from the following information about the patent which is 
> for Debian.
>   http://www.debian.org/legal/patent
>   http://www.debian.org/reports/patent-faq.en.html

Was it your decision to remove the patent-protected modules from OpenCV 
Debian source package? Did you discuss this step with laywers before?

I'm not a lawyer and I'm not position to evaluate the scope of the 
patent in question. But I've a slightly different point of view. In 
particular, I don't think that patent issues should be treated with 
anticipatory obedience (no offense intended here). Most patents are only 
valid in specific countries anyway, or they're not enforced at all.

Do you know of any cases where the SIFT patent has been enforced by the 
patent holder?

To my knowledge, software distributed in Debian packages violates 
several patents.

Also, I understand the Community Patent FAQ in a way that it doesn't 
suggest to not distribute patent-protected software at all. In 
particular, source code distribution shouldn't be a problem at all. 
Actually, it's not clear yet from a legal point of view, whether 
sourcecode distribution violates patents at all. FLOSS laywers say it 
doesn't. See section "I have heard that distributing source code is 
safer than distributing object code. Is that true?" in the FAQ.

Last but not least, the patent in question is hold by a US university. I 
guess chances that they try to enforce the patent against open source 
projects i rather low. Maybe one should ask them explicitely?

I suggest to discuss this issue with patents at debian.org

Kind regards,
  jonas