[poppler] optimized pdf rendering

[Erik Rehn]

Hey Popplers!

This is my first message to this list, hope there is some activity. :)

Anyway, im doing some research into the field of pdf rendering and came 
across poppler/xpdf which seems to be quite easy to work with. Now I 
have some questions for you guys :)

How fast is Poppler compared to other pdf libraries, commercial and open 
source? What im looking for is the fastest way possible to render pdfs 
into bitmaps. Ive done some testing with the pdftoppm tool and it  seem 
to be slightly slower than for instance Foxit's SDK.

Is there any optimization that could be done to speed up the rendering? 
My goal is to develop a server side pdf rendering engine which clients 
can request individual pages from. If for instance the same page is 
requested twice but in different sizes is there any part of the 
rendering process that could be cached to save work?
One thing would be to cache PDFDoc objects to avoid parsing the same pdf 
over and over, does anyone have any thoughts on that?

Thanks for your help!

Best regards,
Erik Rehn