[poppler] about patterns

[Leonard Rosenthol]

At 06:55 PM 8/20/2006, Krzysztof Kowalczyk wrote:
>However, it takes ungodly amount of time to render (minutes on a 3.2
>GhZ machine)

         Rendered for me (finally!) as well - and incorrectly.


>  and slightly differs from how FoxIt renders it (the
>values in graph look like dithered grayscale while foxit renders it as
>solid grey).

         It also renders different than Acrobat - I've sent the file 
to Derek.  I assume that was OK.  If not, let me know and I'll tell 
Derek to kill it.


>  There must be some terrible edge case in poppler -
>rendering of a simple document like this should be instantenous.

         It's quite an unusual edge case - and a VERY EVIL PDF.

         The pattern consists of a VERY TINY inline image that has to 
be tiled across some interesting (irregular) paths.  And, as noted, 
since Xpdf/Poppler doesn't cache - it all gets processed and 
rerendered each time, leaving to quite a LOT of overhead.


>It would be great if someone figured out and fixed those super-slow 
>cases (I'm not
>much of a PDF expert).

         We are working on a variety of performance improvements to 
the Xpdf/Splash rendering engine (at a client's behalf) and will 
submit our changes directly to Derek for inclusion in Xpdf which will 
then find their way back to Poppler (sorry for the roundabout route, 
but that's what we have to do because of the GPL).


LDR

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Leonard Rosenthol                            <mailto:leonardr at pdfsages.com>
Chief Technical Officer                      <http://www.pdfsages.com>
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