[poppler] Trying to extend pdftoppm to use CairoOutputDev

[Adrian Johnson]

mpsuzuki at hiroshima-u.ac.jp wrote:
>> The resolution option "-r" is not required (and doesn't do
>> anything) when using -pdf or -ps.
> 
> I see. When the positions to crop are calculated from the
> options -x, -y, -W and -H , which unit is used? Fixed dpi
> (150 or 72) is assumed?

PDF and PS units are points. 1 point is 1/72 of an inch.