[UFO Chicago] The Two-Stage Solution

[Neil R. Ormos]

Jay F. Shachter wrote:

> The problem, you will recall, is that the recent
> versions of ghostscript no longer convert from
> PostScript or PDF to GIF.  Ghostscript use to do
> it, but recent versions are unwilling to. [...]

> A two-stage solution has been proposed: use
> ghostscript to convert from PostScript or PDF to
> some other image format, [...]  and then use
> ImageMagick to convert from that other image
> format to gif: [...]  This works.

> I have, until now, been employing a different
> solution, [importing] the GIF conversion
> functions [from old versions gs], and I added
> them to the source code of the subsequent
> versions of gs, and then rebuilt gs. [...]  This
> worked until version 9.  Version 9 changed the
> interface to the conversion functions, and I was
> unwilling to spend the time necessary to rewrite
> the GIF conversion functions to support the new
> interface.  [...]

> Both of these solutions, though, are bogus.  Why
> was the GIF conversion functionality taken out
> of GhostScript version 5?  Because someone found
> out that it was patented?  Even if that was
> true, surely the patent has expired by now.
> Patents are short-lived.  GhostScript should
> support GIF conversion.  My original question
> remains: Why doesn't it?

That question, while appearing to be simple, has answers at several levels of abstraction, and might not even be a question, but rather a complaint.

At the simplest level, the question is answered by your own words: "I was unwilling to spend the time necessary to rewrite the GIF conversion functions to support the new interface."  Evidently, you haven't submitted a patch.  Have you filed a bug-tracker request that the GIF output driver be restored?

In case "why" is really a complaint arising from your sense of insult, from a Free Software perspective, that the GIF output driver should never have been removed in the first place, or that the GIF functionality should promptly have been restored by the upstream developers or Linux distribution maintainers upon the expiration of whatever patents were speculated to have required the removal, the fact that gs is licensed as Free Software (or something like it) also gives you the power to fix the problem yourself, and it would appear you already have the skills to do so.

I disagree with the assertion that the two-step solution of: (a) using gs to produce an intermediate image file; and (b) using Image Magick to convert the intermediate image file to a GIF is bogus.  You've acknowledged it works, and writing a shell wrapper to orchestrate the steps--including reasonable argument handling and error checking--would probably have taken you less time than did your posts here.