PanoTools:
Re: Re: PTGui 5.0beta3
JD Smith 2005-Sep-14 00:54:19
On Tue, 13 Sep 2005 23:40:30 +0200, Fulvio Senore wrote:
> JD,
>
> let me disagree. First you are talking about "a powerful yet poorly
> integrated collection of GPL'd tools", but PTStitcher is not open source,
> and Autopano-SIFT came after Autopano that is not open source, and the
> SIFT algorithm is patented, so your argument seems to be a little weak.
>
> Panorama Tools has become a popular software only because somebody wrote
> two closed source front ends (hugin came later). Nobody in this planet
> would have used PT without front ends, so it does not seem to me that
> front ends have only taken without giving.
I answered that already, but PTStitcher had no compelling need to be
open, since Prof. Dersch owned the copyright on the PanoTools library,
and was free to release it however he liked (I personally think it was
an oversight, or poor timing w.r.t the IPIX situation). The fact that
PTStitcher wasn't open wasn't some sort of explicit permission to
create other non-free tools which linked to the PanoTools library.
The "patent-pending" SIFT algorithm has nothing to do with the
copyright issue I'm speaking of. The argument for GPL infringement is
not weak, it is absolute. You simply *cannot* link to GPL'd libraries
without also GPL'ing your source. This is made abundantly clear by
the GPL license, and in numerous FAQs. Running enblend as a separate
executable is less clear of an issue, but dynamically linking in
libpano12 is not an ambiguous situation: this code must be GPL'd.
You say no one would have used PT without the front-ends, I counter
with how many powerful flexible panorama programs would have been
written without PT, from scratch? PanoTools would exist (perhaps
languishing, perhaps unpopular) without PTGui/Assembler/Mac; these
would not have existed without PT, plain and simple. That said, I
first used PT without the front ends, and wholeheartedly agree with
you that they did much to popularize and attract attention to
PanoTools. Most developers here probably came to PanoTools via one of
the front-ends. This was the comfortable "look the other way"
situation we found ourselves in for many years. In a sense, they
needed each other, and while the front-ends kept the division clear --
contribute to the external libraries, improve the internal interface
to them -- everyone benefited. The front-end builders were giving as
well as taking, and even though it didn't follow the exact letter of
copyright law, it was a workable arrangement. Now, however, it seems
at least one of the front end tools is leveraging the position it
gained by having free and unfettered access to PanoTools/enblend/etc.,
and taking its full development closed source. Are there other
non-GPL'd tools in use? Of course (smartblend, autopano, PTLens,
etc.). This doesn't invalidate the point.