[IPOL discuss] Vector graphics on IPOL: which format to use?

[Miguel Colom]

Dear all,

the SVG test page [1] has been updated to show the SVG --> PNG fallback.
That is, rendering an alternate PNG (or any other valid format) image when
the browser is unable to render a SVG file.

In my opinion, the web server should detect when it's been asked for a
fallback image and should generate the PNG version of the SVG on the fly.

Best,
Miguel

[1] http://dev.ipol.im/~colom/svg/test.html

> Hi miguel,
>
> If I didn't miss some mails, the issue of vector image formats is
> still not resolved. could you add the solution described hereafter to
> your test page? I'd like to come to a conclusion.
>
> ----- Forwarded message from Nicolas Limare
> <nicolas.limare at cmla.ens-cachan.fr> -----
>
> Date: Mon, 4 Jul 2011 12:10:26 +0200
> From: Nicolas Limare <nicolas.limare at cmla.ens-cachan.fr>
> To: IPOL general discussions <discuss at list.ipol.im>
> Subject: Re: [IPOL discuss] Vector graphics on IPOL: which format to use?
>
> [...]
>
>> I do like the idea of detecting old browsers and going with a
>> fallback.  Maybe the demo system could first determine the browser,
>> then set an "SVG supported" flag if the browser is known to support
>> SVG.  The demo would generate an SVG, and if the "SVG supported" flag
>> is not set, use for example ImageMagick's "convert" program to
>> rasterize to PNG.  The results page would then show depending on the
>> flag either the PNG or the SVG as an embedded SVG object.
>
> I think we don't need to detect and handle SGV support. It seems that
> with the <object> syntax we can display a PNG file if the browser
> doesn't support SVG.
> ->
> http://tavmjong.free.fr/INKSCAPE/MANUAL/html/Web-Use.html#Web-Use-Object
>
> I don't want to spend time doing web development, browser detection
> and javascript hacking[*], I prefer to work on, well, image processing
> code :) So, if the SVG+PNG fallback solution works well, we only need
> to add a generic svg-png conversion tool in the demo library, and use
> the <object> syntax for dual support in all our templates. Once 95% of
> the browsers support SVG, we can drop the PNG fallback.
>
> @miguel: could you add the SVG+PNG solution to your test page?
>
> Finally, even it IE8 users can see a PNG rendering of the svg image,
> they might want to download/edit a vector file. And here comes again the
> question, which format should be available for *download*? Which
> solutions are available on the desktop to view/edit vector files?
>
> If viewing is the only requirement, I think PDF is the good choice,
> because PDF readers are available everywhere. For editing, the
> Wikipedia comparison[1] tells me that all the major vector editors
> support SVG import, while some of them can't read PS/EPS/PDF.
> And lots of SVG viewers are available[2]. So maybe we can restrict
> ourself to SVG (simpler, less work, less maintenance) and hint at some
> software solutions, the same way we mention VRML readers for 3D data.
>
> [1]
> http://en.wikipedia.org/wiki/Comparison_of_vector_graphics_editors#File_format_support
> [2]
> http://en.wikipedia.org/wiki/Scalable_Vector_Graphics#Software_and_support_in_applications
> [*] all this web hacking is utterly unscientific, full of heuristics,
>     kludges, multi-layered partial solutions and undocumented bugs
>     turned features in a perpetually changing environment, and never
>     provides the satisfaction to obtain, even after long hours (days...)
>     of work, a solution that "just works"...
>
> --
> Nicolas LIMARE - CMLA - ENS Cachan
> http://www.cmla.ens-cachan.fr/~limare/
> IPOL - image processing on line
> http://www.ipol.im/
>
>
>
> ----- End forwarded message -----
>
> --
> Nicolas LIMARE - CMLA - ENS Cachan
> http://www.cmla.ens-cachan.fr/~limare/
> IPOL - image processing on line
> http://www.ipol.im/
>